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January 16, 2004 Pete Dye King County Department of " Development & Environmental Services 900 Oakesdale Avenue SW Renton, WA 98055-1219 RE: East Renton Property: L02POOOS Site Access Exhibit Dear Pete, A few weeks back I inquired about the need for the future southerly access we had proposed for the East Renton Plat. It is our hope to remove this access from the 'proposaL There are five existing homes located in between the East Renton and Shamrock proposals. Given the extent and proxiinity of what is lo~ated on these parcels, we would like to know if we can remove the' proposed southerly access. The northerly access to the future Ironwood plat is still shown. Enclosed is a copy of the·aeria·l site plan exhibit by Triad which shows the East Renton & Shamrock plats along with all proposed accesses. Should you have any questions or need any additional information, please contact me at (425) 825-1955. Thank you for your attention to this matter. Sincerely, ?fA Sara Slatten CamWest Development, Inc. enclosure ( .. ' .. OFFICE OF THE HEARING EXAMINER KING COUNTY, WASHINGTON 400 Yesler Way, Room 404 Seattle, Washington 98104 Telephone (206) 296-4660 Facsimile (206) 296-1654 Email: hearex@metrokc.gov April 5, 2007 REPORT AND DECISION SUBJECT: Department of Development and Environmental Services File No. L02P0005 Proposed Ordinance no. 2007-0010 EAST RENTON Preliminary Plat Application Location: West of 148th Avenue Southeast at approximately Southeast 120th Street, Renton Applicant: CamWest Real Estate Dev., Inc. represented by Robert Johns, Attorney Johns Monroe Mitsunaga 1601 -I 14th Ave. SE, # 110 Bellevue, Washington 98004 Telephone: (425) 467-9960 Facsimile: (425) 451-2818 King County: Department of Development and Environmental Services (DDES) represented by Karen Scharer 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 Telephone: (206) 296-7114 Facsimile: (206) 296-7051 SUMMARY OF RECOMMENDATIONSfDECISION: Department's Preliminary Recommendation: Department's Final Recommendation: .Examiner's Decision: EXAMINER PROCEEDINGS: Hearing Opened: Continued for Administrative Purposes: Hearing Closed: Approve subject to conditions Approve subject to conditions (modified) Approve subject to conditions (modified) March 22, 2007 [~~ M~h-22, ~W+1 'Q) o /. ~feii 23, 2001', I 0 ru DEC 2 6 ZD87 07 V()cJ.~.~. L02P0005-East Renton 2 The public hearing on the proposed subdivision of East Renton was conducted concurrently with the public hearing on the proposed subdivision of Rosemonte (DDES File No. L03POOI8). Participants at the public hearing and the exhibits offered and entered are listed in the attached minutes. At 12:31 p.m. the hearing was continued for administrative purposes, to allow for the submission of proposed exh. no. 29, that would set forth the final recommendation of the department concerning revisions to recommended conditions #'s 6, 20, 21 and 22. Exhibit 29 was received by the Hearing Examiner on March 22, 2007, and the hearing was declared closed on March 23, 2007 A verbatim recording of the hearing is available in the office of the King County Hearing Examiner. ISSUES AND TOPICS ADDRESSED: Future development tract Red-tailed hawks nest Safe walking conditions SUMMARY: • • • Recreation area Wetland buffers Surface water drainage The proposed subdivision of 17.01 acres into 66 lots in the urban area is approved subject to conditions. FINDINGS, CONCLUSIONS & DECISION: Having reviewed the record in this matter, the Examiner now makes and enters the following: FINDINGS: I. General Information: Developer: Engineer: STR: Location: Zoning: Acreage: Number of Lots: Density: Lot Size: Camwest Real Estate Development, Inc. 9720 NE 120" Place, Suite 100 Kirkland, W A 98034 Contact: Sars Slatten 425-825-1955 Triad Associates 12112115" Ave NE Kirkland, W A 98034 Contact: Gerry Buck 425-821-8448 10-23-05 West of 148" Ave SE at approximately SE 120" St. Parcel -1023059023 R-4 17.01 acres 66 Approximately 3.9 units per acre Approximately 5,000 square feet in size .,} , . ' .' ',' L02P0005-East Renton Proposed Use: Sewage Disposal: Water Supply: Fire District: School District: Single Family Detached Dwellings City of Renton Water District # 90 City of Renton Issaquah School District Complete Application Date: April 17,2002 3 2. Except as modified herein, the facts set forth in the King County Land Use Services Division's preliminary report to the King County Hearing Examiner for the March 22, 2007, public hearing are found to be correct and are incorporated herein by this reference. The LUSD staff recommends approval of this subdivision,subject to conditions. 3. Development of this subdivision may affect, and lead to the abandonment of, a red-tailed hawks nest on the subject property. The red-trail hawk is not an endangered or threatened species, and no protection of the red-tail hawk is afforded by law or the King County Code within the designated urban area of King County. 4. The applicant has proposed the establishment of Tract E as a "future development" tract. DDES determined that there is no reasonable access available to Tract E that would not cross wetland or wetland buffer. At the hearing the applicant abandoned its request to designate Tract E as a "future development" tract, and proposes to establish that tract as recreation area, to be connected by trail with the designated recreation/detention Tract G within this subdivision and adjacent to the proposed plat OfRosemonte. 5. The applicant has submitted a revised recreation plan for this subdivision and the adjacent plat of Rosemonte (exh. 26). This plan provides adequate area within Tracts C, G and E and within the proposed recreation tract and trail within Rosemonte to serve these plats jointly with well conceived amenities for recreation and open space, consistent with the requirements of the King County Code. To the extent that a portion of the recreation area necessary to meet the requirements for the plat of Rosemonte is located on the East Renton property, that can be corrected by boundary line adjustment or recording the two plats as a single plat, ifDDES determines that it is necessary to do so. 6. Wetland buffers within this subdivision will need to be modified, utilizing the buffer averaging provisions of the critical areas code, to accommodate the proposed alignment of 145th Avenue Southeast in the vicinity of the north property line, and adding buffer to mitigate the impacts of the proposed trail corridor within Tract F (between Tracts E and G), in accordance with the provisions ofKCC 2IA.24.045.D.47.b. 7. The proposed subdivision will provide for safe walking conditions for students who will walk to Apollo Elementary School on southeast I I 7th Street by constructing urban improvements to 148th Avenue Southeast from the plat to Southeast I I 7th Street. A school crosswalk (crossing 148th Avenue Southeast) is located on the north side of Southeast I I 7th Street, where an existing walkway is used by students to travel along the north side of Southeast I I 7th Street east from 148th Avenue Southeast to the school. This crosswalk also serves students walking from the area north of Southeast I 17th Street. Consequently', the crosswalk should be maintained on the L02P0005-East Renton 4 north side of Southeast I I 7th Street unless it is physically impractical to do so because of constraints resulting from the topography within the right-of-way for 148th Avenue Southeast, south of Southeast II 7th Street. If those constraints preclude extending curb, gutter and sidewalk from the plat of East Renton to the north side of Southeast I I 7th Street, the crosswalk can be relocated to the south, and improvements made on the east side of 148th Avenue Southeast to Southeast I 17th Street. 8. The conceptual review of drainage plans has shown that there are no downstream impacts likely to OCCur from development of the subject property if Level I flow control and basic water quality treatment improvements are designed and constructed in accordance with the 1998 King County Drainage Manual. The final drainage plan will include calculations to assure that the capacity of drainage facilities and discharge rates will be consistent with those flow control standards. CONCLUSIONS: I. If approved subject to the conditions recommended below, the proposed subdivision will comply with the goals and objectives of the King County Comprehensive Plan, subdivision and zoning codes, and other official land use controls and policies of King County. 2. If approved subject to the conditions recommended below, this proposed subdivision will make appropriate provision for the public health, safety and general welfare, and for open spaces, drainage ways, streets, other public ways, transit stops, potable water supply, sanitary waste, parks and recreation, playgrounds, schools and school grounds and safe walking conditions for students who only walk to school; and it will serve the public use and interest. 3. The conditions for final plat approval recommended below are in the public interest and are reasonable and proportionate requirements necessary to mitigate the impacts of the development upon the environment. 4. The dedications ofland or easements within and adjacent to the proposed plat, as required for fmal plat approval or as shown on the proposed preliminary plat submitted by the Applicant on March 17, 2006 and the conceptual recreation plan .submitted March 22,2007 (exh. 26), are reasonable and necessary as a direct result of the development of this proposed plat, and are proportionate to the impacts of the development. 5. No provisions are required to be made by this subdivision for the protection of the red-tail hawks nest(s) on the site. 6. The proposed future development designation for Tract E has been withdrawn by the applicant, and that tract shall be a portion of the designated recreation area for the current development. 7. The proposed conceptual recreation plan submitted as exh. no. 26 is a reasonable and appropriate plan to serve the plats of East Renton and Rosemonte jointly. Minor alterations may be made in the final design and review by DDES, and boundary adjustments, if necessary, may be made to comply with provisions ofKCC 2IA.l4.180-200. , . L02P0005-East Renton 5 8. Revisions to the wetland buffers will be necessary to comply with the provisions of the King County Critical Areas Code, to permit construction of l45th Avenue Southeast in the vicinity of the north property line and to mitigate the impacts of the trail connecting Tracts E and G. 9. In order to provide for safe walking conditions for students walking from this development to Apollo Elementary School, urban improvements must be made to 148th Avenue Southeast north from the proposed plat to the north side of Southeast II 7th Street. These improvements should .be made to the west side of 148th Avenue Southeast to the extent it is feasible to do so. In the event it is not practical to construct improvements extending to the existing crosswalk located at the north side of Southeast I 17th Street, a crosswalk may be established south of Southeast I I 7th Street and a safe wallcWay provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast I I 7th Street. 10. Calculations for surface water detention facilities shall assure that the release of storm water from the site does not exceed the rates allowed by the 1998 King County Drainage Manual for achieving Level I flow control. DECISION: The proposed preliminary plat of East Renton, as revised and received on March 17,2006, is approved, subject to the following conditions of final plat approval: I. . Compliance with all platting provisions of Title 19A of the King County Code. 2. All persons having an ownership interest in the subject property shall sign on the face of the final plat a dedication that includes the language set forth in King County Council Motion No. 5952. 3. The plat shall comply with the base density and minimum density requirements of the R-4 zone classification. All lots shall meet the minimum dimensional requirements ofthe R-4 zone classification or shall be as shown on the face of the approved preliminary plat, whichever is larger, except that minor revisions to the plat which do not result in substantial changes may be approved at the discretion of the Department of Development· and Environment Services. Any/all plat boundary discrepancy(ies) shall be resolved to the satisfaction ofDDES prior to the submittal of the final plat documents. As used in this condition, "discrepancy" is a boundary hiatus, an overlapping boundary or a physical appurtenance which indicates an encroachment, lines of possession or a conflict of title. 4. The applicant must obtain final approval from the King County Health Department. 5. All construction and upgrading of public and private roads shall be done in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). (Also see conditions 8 and 24.) L02P0005-East Renton 6. The applicant must obtain the approval of the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the King County Code. 6 All future residences constructed within this subdivision are required to be sprinklered (NFPA 13D) unless the requirement is removed by the King County fire Marshal or hislher designee. The Fire Code requires all portions of the exterior walls of structures to be within 150 feet (as a person would walk via an approved route around the building) from a minimum 20-foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement, driving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. The road width requirement applies to both on-site access and roads accessing the subdivision. 7. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location oflots as shown on the preliminary approved plat. Preliminary review has identified the following conditions of approval, which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual. DDES approval of the drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review shall be shown on the engineering plans. c. The following note shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DDES and/or the Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for individual lot infiltration systems, the systems shall be constructed at the time of the building permit and shall comply with the plans on file." d. Storm water facilities shall be designed using the KCRTS level one flow control standard. Water quality facilities shall also be provided using the basic water quality" protection menu. The size of the proposed drainage tracts may have to increase to accommodate the required detention volumes and water quality facilities. All runoff control facilities shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for recreation space in accordance with KCC 2IA.14.lS0. ' .. L02P0005-East Renton 7 e. The applicant has received approval for two drainage adjustment applications regarding designs for the discharge of stonn water and a shared facility detention pond. The adjustment decisions are contained within file numbers L02V0089 and L04V0103. During final review of the engineering plans, all applicable conditions of the adjustment approvals shall be satisfied including requirements for the shared facility located offsite within the plat of Rosemonte. f. As stated in the drainage adjustment decision, the ofTsite drainage pond shall be designed using the Level I flow control standard. Basic water quality standards are also required for design of the facility. If a wet pond facility is provided for water quality, the design shall comply with the 3:1 flow length ratio as outlined on page 6-72 in the drainage manual. For evaluation of the onsite stonn vault and the offsite detentionpond, a soils report shall be prepared by a geotechnical engineer to evaluate the soils and groundwater conditions. g. For any proposed bypass of stonn water from the flow control facility, the final drainage designs shall comply with applicable design requirements in the drainage manual as outlined on pages 1-36 and 3-52. h. As required by Special Requirement No.2 in the drainage manual, the 100-year floodplain boundaries for the onsite wetlands shall be shown on the final engineering plans and recorded plat. Access and Roads 8. The proposed subdivision shall comply with the 1993 King County Road Standards (KCRS) including the following requirements: a. During preliminary review the applicant submitted a road variance application (File No. L03V0049), regarding the crest vertical curve and substandard stopping sight distance along the plat frontage. In response to the variance application, the King County Road Engineer provided a decision letter dated October 20, 2004 which approved the variance based upon specific design criteria for constructing 148 th Ave SE. -As noted in the variance decision, the crest curve on 148 th Ave SE must be reconstructed to provide 455 feet of stopping sight distance based upon design criteria with a 2-foot target. The final road improvements and design plans for the project shall demonstrate compliance with all applicable conditions of approval as stated in the variance decision. b. 148 th Avenue SE shall be improved along the frontage as an urban collector arterial including all design criteria from the road variance decision. In accordance with KCRS 2.02, the curb location shall be designed at 22-feet from the road crown to provide full width travel lanes and a bike lane. The preliminary design plans for East Renton shows road grading extending outside the right-of-way on the east side of 148 th Ave SE. During final engineering review, the applicant shall acquire easements for any proposed construction on private property or provide an alternative design which is acceptable to King County for road construction within the existing right-of-way. L02P0005-East Renton 8 c. The project entry road to 148 th Ave SE shall be improved as an urban neighborhood collector. As shown on the preliminary plat, the required right-of-way width is 56 feet d. The proposed roads within the subdivision shall be improved using urban design standards and in accordance with the street classifications shown on the preliminary plat map. e. Tract D shall be improved as a private joint use driveway serving a maximum of two lots. The lots served shall have undivided ownership of the tract and be responsible for its maintenance. As specified in KCRS 3.0IC, improvements shaH include an IS foot paved surface and a minimum tract width of 20 feet. Drainage control shall include a curb or thickened edge on one side. f. Street trees shall be included in the design of all road improvements and shall comply with Section 5.03 of the KCRS. g. Street illumination shall be provided along the plat frontage and at intersections with arterials in accordance with KCRS 5.05. h. The proposed road improvements shall address the requirements for road surfacing outlined in KCRS Chapter 4. As noted in section 4.0IF, full width pavement overlay is required where widening existing asphalt, unless otherwise approved by King County. 1. 14Sth Ave SE is classified as an arterial street which may require designs for bus zones and turn outs. As specified in KCRS 2.16, the designer shall contact Metro and the local school district to determine specific requirements. J. Modifications to the above road conditions may be considered by King County pursuant to the variance procedures in KCRS I.OS. 9. All utilities within proposed rights-of-way must be included within a franchise approved by the King County Council prior to final plat recording. 10. The site plans for East Renton show the northerly road stub for 145 th Ave SE which may extend into the wetland buffer and associated setback within the Rosemont plat. During engineering review for East Renton, a revised road alignment and grading plan shall be provided which demonstrates that road construction within Rosemonte will comply with applicable sensitive area codes. The revised road design and grading plan may result in modification or loss of lots as shown on the preliminary plat. Alternatively, the applicant may seek approval to use buffer averaging as a means to revise the location of the buffer and BSLB to achieve code compliance within Rosemonte. II. There shall be no direct vehicular access to or from 14Sth Ave SE from those lots which abut it. A note to this effect shall appear on the engineering plans and the final plat. 12. The applicant shall provide a safe walking access to Apollo Elementary School with urban improvements along the west side of 14Sth Ave NE to the existing crosswalk on the north side of · . '.' L02P0005-East Renton 9 SE 1170. Sf. This improvement includes urban frontage improvements along property frontage of the Plat of East Renton, urban improvements along frontage of Rosemonte and urban improvements north to the existing crosswalk on the north side of SE 1170. ST. (It is noted that the adjoining plat of Rosemonte also will be subject to urban frontage requirements and urban improvements north to the existing crosswalk on the north side of SE I 17 th ST.) In the event it is not practical to construct urban improvements on the west side of 148th Avenue Southeast extending to the existing crosswalk, a new crosswalk may be established south of Southeast I I 7th Street and a safe walkway provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast I 17th Street. This alternative may use a graded surface on the east side of 148th Ave SE to ensure that school-age pedestrians are provided an acceptable-width walkway surface behind the curbing. The walkway shall be designed to the satisfaction of the school district and DDES. MitigationlImpact Fees 13. The applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either: (I) pay the MPS fee at the Tmal plat recording, or (2) pay the MPS fee at the time of building permit issuance. If the first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All fees required by King County Code 14.75, ,Mitigation Payment System (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building permit application. 14. Lots within this subdivision are subject to King County Code 2IA,43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shall be assessed and collected immediately prior to the recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shall be allocated evenly to the dwelling units in the plat and shall be collected prior to building permit issuance. Wetlands 15. Preliminary plat review has identified specific requirements which apply to this project as listed below. All other applicable requirements from K.c'C. 21A.24 shall also be addressed by the applicant. a. The Class 2 wetland shall have a minimum 50-foot buffer of undisturbed vegetation as measured from the wetland edge. b. Sensitive area tract(s) shall be used to delineate and protect sensitive areas and buffers in development proposals for subdivisions and shall be recorded on all documents of title of record for all affected lots. LD2P0005-East Renton 10 c. Buffer width averaging may be allowed by King County if it will provide additional protection to the wetland/stream or enhance their functions, as long as the total area contained in the buffer on the development proposal site does not decrease. In no area shall the buffer be less than 65 percent of the required minimum distance. To enstire such functions are enhanced a mitigation plan will be required for the remaining on-site sensitive areas. An enhancement plan shall be submitted for review during engineering review. d. A IS-foot BSBL shall be established from the edge of buffer and/or the sensitive areas Tract(s) and shown on all affected lots. e. To ensure long term protection of the Sensitive Areas a split-railed fence of no more than 4 feet in height shall be installed along the Sensitive Area Tract boundaries in the area of proposed lots. Sensitive Area signs shall be attached to the fence at no less than 100 foot intervals. f. If alterations of streams and/or wetlands are approved in conformance with K.C.C. 21 A.24, then a detailed plan to mitigate for impacts from that alteration will be required to be reviewed and approved along with the plat engineering plans. A performance bond or other fmancial guarantee will be required at the time of plan approval to guarantee that the mitigation measures are installed according to the plan. Once the mitigation work is completed to a DDES Senior Ecologist's satisfaction, the performance bond may be replaced by a maintenance bond for the remainder of the five-year monitoring period to guarantee the success of the mitigation. The applicant shall be responsible for the installation, maintenance and monitoring of any approved mitigation. The mitigation plan must be installed prior to final inspection of the plat. g. Prior to commencing construction activities on thi: site, the applicant shall temporarily mark sensitive areas tract(s) in a highly visible manner, and these areas must remain so marked until all development proposal activities in the vicinity of the sensitive areas are completed. h. During engineering plan review the applicant shall provide a wetland hydrology analysis to demonstrate how the wetland hydrology will be maintained post-construction. i. Detention out-fall structures maybe permitted within the wetland/stream buffers, however, structures shall be located in the outer edge of the buffer, if possible. All buffer impacts shall be mitigated. 16. Development authorized by this approval may require other state and/or federal permits or approvals. It is the applicant's responsibility to correspond with these agencies prior to beginning work on the site. 17. During engineering review, the plan set shall be routed to the sensitive areas group to determine if the above conditions have been met. ' .. ' L02P0005-East Renton 11 Geotechnical 18. The applicant shall delineate all on-site erosion hazard areas on the final engineering plans (erosion hazard areas are defined in KCC 21A.06.415). The delineation of such areas shall be approved by a DOES geologist. The requirements found in KCC 21 A.24.220 concerning erosion hazard areas shall be met, including seasonal restrictions on clearing and grading activities. Sensitive Area 19. The following note shall be shown on the final engineering plan and recorded phil: Other RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tract/sensitive area and buffer conveys to the public a beneficial interest in the land within the tract/sensitive area and buffer. This interest includes the preservation of native vegetation for all purposes that benefit the public health, safety and welfare, including control of surface water and erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tract/sensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tract/sensitive area and buffer the obligation, enforceable on behalf of the public by King County, to leave undisturbed all trees and other vegetation within the tract/sensitive area and buffer. The vegetation within the tract/sensitive area and buffer may not be cut, pruned, covered by fill, removed or damaged without approval in writing from the King County Department of . Development and Environmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tract/sensitive area and buffer and the area of development activity must be marked or otherwise flagged to the satisfaction of King County prior to any clearing, grading, building construction or other development activity on a lot subject to the sensitive area tract/sensitive area and buffer. The required marking or flagging shall remain in place until all development proposal activities in the vicinity of the sensitive area are completed. No building foundations are allowed beyond the required 15-foot building setback line, unless otherwise provided by law. 20. The plat design shall be revised to provide the minimum suitable recreation space consistent with the requirements ofK.C.C. 2IA.14.IBO and K.C.C. 21A. 14.190 (i.e., minimum area, as well as, sport court[s], children's play equipment, picnic table[s], benches, etc.), as shown on hearing ew. no. 26. a. A detailed recreation space plan (i.e., location, area calculations, dimensions, landscape specs, equipment specs, etc.) shall be submitted for review and approval by DOES prior to or concurrent with the submittal of engineering plats. L02P0005-East Renton b. A perfonnance bond for recreation space improvements shall be posted prior to recording of the plat. 12 21. Tract E shall be designated for recreational area, With an approved trail (across wetland buffers) extending from the recreational Tract'G and functioning as an extension of recreation from Tract G. Plans for the tract -designation and design, shall comply with codes and shall be to the satisfaction of DDES prior to engineering approval. 22. A homeowners' association or other workable organization shall be established to the satisfaction of DDES which provides for the ownership and continued maintenance of the recreation, open space and/or sensitive area tract(s) which combines usageofrecreation area within L03POOl8, the plat of Rosemonte, pursuant to hearing exh. nO. 26. (See condition no. 25.) 23. Street trees shall be provided as follows (per KCRS 5.03 and K.C.C. 21A.16.050): . a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. c. If King County determines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right-of-way line. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the county has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DDES if located within the right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or stonn sewers, or that is not compatible with overhead utility lines. f. The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DDES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at (206) 684-1622 to detennine if 148 th Ave SE is On a bus route. If 1 48 th Ave SE is a bus route, the street tree plan shall also be reviewed by Metro. h. The street trees must be installed and inspected, or a perfonnance bond posted prior to recording of the plat. If a perfonnance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the L02P0005-East Renton 13 SEPA trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year. After one year, the maintenance bond may be released after DDES has completed a second inspection and detennined that the trees have been kept healthy and thriving. 1. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on the current county fees. 24. The following have been established by SEPA as necessary requirements to mitigate the adverse environmental impacts of this development. The applicants shall dernonstrate compliance with these items prior to final approval. (I.) To mitigate the significant adverse impact the plat of East Renton will have on the intersections ofSR 900/14Sth Ave SE and SR 900/1 64th Ave SE, the applicant shall install, either individually or in conjunction with other development projects in this area, the following improvements at the SR 900/l4S th Ave intersection: • A traffic signal, and • Eastbound and westbound left turn lanes The design for the SR 900/l4Sth Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by King County to the extent such improvements are located in County right-of-way). In addition, at a minimum, the existing " entering sight distance looking east for the north and south legs of the intersection (602 feet and "386 feet, respectively) shall not be reduced as part of the intersection improvements. Documentation shall be submitted to show this requirement is met. All construction work associated with the intersection improvements shall be completed between April I ~ and September 30th • This seasonal restriction shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantee with WSDOT which assures the " installation of these improvements within two years of the recording of East Renton. In this event, intersection improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-rata share dollar amount to be paid shall be set by WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip distribution for East Renton L02P0005-East Renton 14 • The total trips contributed to the intersection of SR 900.148 th Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P3008), East Renton (L02P0005), Shamrock (L02POO 14), Rosemonte (aka Ironwood -L03POO 18), Martin (L05POO 19) and any future land use applications submitted to King County for which compliance with the King County Intersection Standards (KCC 14.80) is required at either the SR 900/148 t1i Ave intersection, or the SR 90011 64 th Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu of the approach described above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years of the date of . recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21 A.28.060A] (2.) Documentation shall be provided to demonstrate to the satisfaction of WSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900/148 th Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 148 th Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 21A.28.060A] 25. The recreation area may serve the adjacent plat of Rosemonte. Ifnecessary, boundary line adjustments may be approved to establish a portion of the East Renton plat recreation area as a part of the Rosemonte Plat, or the two plats may be recorded as a single plat. 26. Wetland buffer averaging or additional buffer are required to compensate for reduction of wetland buffers adjacent to 145th Avenue southeast, as proposed in the vicinity of the north property line, and to compensate for construction of the recreation tract trail through wetland buffer between Tracts E and G. ORDERED this 5th day of April, 2007. TRANSMITTED this 5th day of April, 2007, to the parties and interested persons of record: Robert L. Anderson PO Box 353 Maple Valley W A 98038 CamWest Devel., Inc. Attn: Sara Slatten 9720 NE 120th PI. #100 Kirkland W A 98034 Kristine & Keith Childs 12004 -148th Ave. SE Renton W A 98059 • • L02P0005-East Renton 15 Claudia Donnelly Renee & Mark Engbaum John Graves 10415 -147th Ave. SE 5424 NE 10th St. Lozier Homes Renton W A 98059 Renton W A 98059-4386 1203 I 14th Ave. SE Bellevue W A 98004 Ralph Hickman Robert D. Johns Rebecca Lind 9720 NE 120th PI. #100 Johns Monroe Mitsunaga City of Renton, EDNSP Kirkland W A 98034 1601 -114th Ave. SE, # 110 \055 S. Grady Way Bellevue W A 98004 Renton W A 98057 Seattle KC Health Dept. Triad Associates Kim Claussen E. Dist. Environ. Health 12112 -115th Ave NE DDESfLUSD 14350 SE Eastgate Way Kirkland W A 98034 MS OAK-DE-OIOO Bellevue W A 98007 Lisa Dinsmore Peter Dye Nick Gillen DDESfLUSD DDESfLUSD DDESfLUSD MS OAK-DE-OIOO MS OAK-DE-OIOO MS OAK-DE-OIOO Shirley Goll Kristen Langley Karen Scharer DDESfLUSD DDESfLUSD DDESfLUSD MS OAK-DE-OIOO MS OAK-DE-OlOO MS OAK-DE-OIOO Steve Townsend Larry West Kelly Whiting DDESfLUSD DDESfLUSD KC DOT, Rd. Srvcs. Div. MS OAK-DE-OIOO MS OAK-DE-OIOO MS KSC-TR-0231 Bruce Whittaker DDESfLUSD MS OAK-DE-OIOO NOTICE OF RIGHT TO APPEAL In order to appeal the decision of the Examiner, written notice of appeal must be filed with the Clerk of the King County Council with a fee of $250.00 (check payable to King County Office of Finance) on or before April 19, 2007. Ifa notice of appeal is filed, the original and six (6) copies ofa written appeal statement specifYing the basis for the appeal and argument in support of the appeal must be filed with the Clerk of the King County Council on or before April 26, 2007. Appeal statements may refer only to facts contained in the hearing record; new facts may not be presented on appeal. Filing requires actual delivery to the Office of the Clerk of the Council, Room 1025, King County Courthouse, 516 3nl Avenue, Seattle, Washington 98104, prior to the close of business (4:30 p.m.) on the date due. Prior mailing is not sufficient if actual receipt by the Clerk does not occur within the applicable time period. The Examiner does not have authority to extend the time period unless the Office of the Clerk is not open on the specified closing date, in which event delivery prior tothe close of business on the next business day is sufficient to meet the filing requirement. L02P0005-East Renton 16 If a written notice of appeal and filing fee are not filed within fourteen (14) calendar days of the date of this report, or if a written appeal statement and argument are not filed within twenty-one (21) calendar days of the date of this report, the decision of the hearing examiner contained herein shall be the final decision of King County without the need for further action by the Council. MINUTES OF THE MARCH 22, 2007, PUBLIC HEARING ON DEPARTMENT OF DEVELOPMENT AND ENVIRONMENTAL SERVICES FILE NO. L02P0005 James N. O'Connor was the Hearing Examiner in this matter. Participating in the hearing were Karen Scharer, Pete Dye and Kristen Langley, representing the Department; Robert Johns representing the Applicant; and Renee Engbaum. Exhibit No. I Exhibit No.2 Exhibit No.3 Exhibit No.4 Exhibit No.5 Exhibit No.6 Exhibit No. 7 Exhibit No.8 Exhibit No.9 Exhibit No. 10 Exhibit No. II Exhibit No. 12 Exhibit No. 13 Exhibit No. 14 Exhibit No. 15 DDES file L02P0005 DDES preliminary report for L02P0005, prepared 1212912006 with attachments as follow: 2.1. Plat Map w/66 Lot Plat Design 2.2. City of Renton Sewer Availability 2.3. Road VarianceIL03V0049 2.4. Surface Water Management VarianceIL02V0089 2.5 Surface Water Management VarianceIL04VOI03 2.6. Density Calculations wlR-4 zoning 2.7 Recreation cross section for Tract G (previously labeled Tract C) Application for land use permit no. AOIPOO71 received 4/3/2002 Environmental checklist received 4/3/2002 Revised SEPA Mitigated Determination of Non significance, date of revised issuance: 12/2912006 Affidavit of posting of Notice of Application indicating posting date of 5/3/2002, received by DDES on 5/312002 Revised Site plan (66 lot preliminary plat map) received 3/17/2006 Assessor's maps (2) SE 10-23-05 & SW 11-23-05 Revised Level I Downstream Analysis by Triad & Associates, received 11124/2004 Traffic Impact Analysis by Gary Struthers Associates received 4/312002 Request for School Information form from the Issaquah School District, received 4/25/2002 King County Certificate of Water Availability, received 4/03/2002 Vicinity Map for L05POOI9, L03POOl8 & L02P0005, prepared by KC staff on 3/19/2007 DDES Field Report and GIS Information dated 5/112002 Revised Wetlands Determination and Habitat analysis by C. Gary Schulz dated 9112/2002 '.it' L02P0005-East Renton 17 Exhibit No. 16 Exhibit No. 17 Exhibit No. 18 Exhibit No. 19 Exhibit No. 20 Exhibit No. 21 Exhibit No. 22 Exhibit No. 23 Exhibit No. 24 Exhibit No. 25 Exhibit No. 26 Exhibit No. 27 Exhibit No. 28 Exhibit No. 29 JNOC;gao L02POO05 RPT Watertype/stream Classification Survey comments from Washington Trout, dated 10/1512004 Drainage outfall report by Associated Earth Sciences, Inc., dated 912412002 Boundary line adjustment proposal with attached map, dated 5/312004 Not entered Response to East Renton Transportation Comments by Gary Struthers Associates, Inc., dated 1123/2003 Washington State Department of Tranportation comments regarding Traffic Impact Analysis, dated 11113/2002 Letter from Claudia Donnelly dated 6/13/2003 regarding basin plan, with 2 attachments Note from Claudia Donnelly with attached copy of 11112/03 newspaper article regarding transportation model City of Renton comments, regarding sewer service, dated 3/28/2002 Revised language for Condition 6 Conceptual recreation plan by Triad Associates Revised preliminary plat received March 22, 2007 Letter from Renee and Mark Engbaum dated March 22, 2007, with attached map indicating the location of their property Revisions to Conditions 20, 21 and 22 ., <® King County DEPARTMENT OF DEVELOPMENT AND ENVIRONMENTAL SERVICES , LAND USE SERVICES DIVISION KING COUNTY, WASHINGTON PRELIMINARY REPORT TO THE HEARING EXAMINER March 22, 2007 -PUBLIC HEARING AT 9:30 A.M. DOES Hearing Room 900 Oakesdale Avenue Southwest Renton, WA 98057-5212 Phone: (206) 296-6600 PROPOSED PLAT OF EAST RENTON FILE NO: L02P0005 PROPOSED ORDINANCE NO: 2007-0010 A. SUMMARY OF PROPOSED ACTION: This is a request for a subdivision of 17.01 acres into 66 lots for detached single· family dwellings. The propDsed density is 3.9 dwelling units per acre based on gross area. Density based on net buildable area of 1,1.88 acres is 5.6 units per acre. The lot sizes are predominately 5,000 square feet. Sec Attachment 1 for a 'copy of tho proposed plat map. B. GENERAL INFORMATION: Developer. Engineer: STR: Location: Zoning:' Acreage: Number of Lots: Densny: Lot Size: Proposed Use: Sewage Disposal: Water Supply: Fire District: School District: Camwest t;:eal Estate'Oevelopment, Inc. 9720 NE 120~ Place. SUite 1 DO Kirkland, WA 98034, Contact: Sars Slatten 425-825-1955 Triad Associates 12112115" Ave NE Kirkland, WA 98034 Contact: Gerry BUCK 425·821-8448 10-23·05 West of 148~ Ave SE at approximately SE120~ SI. Parcel -1023059023 R-4 17.01 acres 66 Approximately 3.9 units per acre Approximately 5,000 square feet in size Single Family Detached Dwellings City of Renton Water District # 90 City of Renton Issaquah School District Complete Application Date: April 17, 2002 C. HISTORY/BACKGROUND: The Subdivision Technical Commitlee (STC) of King County has conducted an on- site examination of the subject property. The STC has discussed the proposed devolopment with the applicant to clarify technical details of tho application, and to determine the compatibility of this project with applicable King County plans, codes, and other official documents regulating this development. As a result of proliminary discussions, the applicant presented the Technical Committee with numerous revision~ with the most recent plat revision 011 March 17, 2006. Tho modifications from "the initial submittal include; • Rovlsed entrance to the plat • Rovised location of recreational space • Clarificaiion of t~e sidewalk improvements to be constructed along frontage and within the plat. • Adjustment to the buffer and BSBL lines associated with the on site wetlands. • Revised plat boundaries, eliminating the far west portion (2+ acres) from the plat application. Boundary revision was completed under file L04L0055 end recorded under # 20041223900001. The purpose of the boundary adjustment was to separate that portion of the site annexed into the City of Renton under Ordinance 5147, effective on July 6, 2005. • SWM Adjustment L02VOOa9 approved allowing the diversio'1 of runoff to a single facility, ' • Subsequontly SWM Adjustment L04V0103 was approved 3124105 for shared facility concept of the northeast comer of East Renton to utilize eastern drainage facility in Rosemonte. • Road Vartanco L03V0049 approved 10/2012004 for a 620 -foot vertical curve with 455 feel of stopping sight distance, utilizing a two-foot target. Additionally approved is the slight grade break (under 1%) aUha north end of the vertical curve. D. THRESHOLD DETERMINATION OF ENVIRONMENTAL SIGNIFICANCE: Pursuant to the State Environmental Policy Act (SEPA), RCW 43.21 C, the responsible official of LUSD issued a mitigatod threshold determination of non- significance (MDNS) for the proposed development on December 15, 2006. This detennlnation was based on the review of the environmental checklist and other pertinent documents, resulting in the conclusion that the proposal would not cause probable significant adverse Impacts on the environment provided mitigations measures are implemented. Subsequently, staff recognized Incorrect references to other subdivisions and Issued a REVISED MDNS on December 29, 2006 referencing the following mitigations: 1. To m~igate the significant adverse impact the pial of East Renlon will have on the intersections of SR 900/148'h Ave SE and SR 9001164~ Avo SE, the applicant shall install, either individually or In conjunction with other development projects In this area, the following improvements at the SR 900/148th Ave intersection: • A traffic signal, and • Eastbound and westbound loft tum lanes FILE NO L02P0005 Page 2 The. design for the SR 900/148'h Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by . King County to the extent such improvemAnts are located in County right-of- way). In addition, ot a minimum, the exlsling entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet, respectively) shall not be 'reduced as part of the intersection improvements. Documentation shall be submittod to show this requirement is met. All ' construction work associ£lted with the intersection improvements shall be completed between April 1 st and September 30 th . This sOflsonat restriction shaH be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantoe with WSDOT which assures the Installation of these improvements within two years of the recording of East Renton. In this event, intersection improvement design must be approved by WSDOT prior to King County approval of the.engineering plans for Ens! Renton. If the above-noted intersection improvements have already been made by others prior to the. recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these Improvemonts, thon the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or -bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-ratn sharo dollar amount to be paid shall be set by W800T, and documentaUon shall be pruvided by the East Renton applicant to the King County land Use Services Division to show this payment hEls been mada, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: The final East Renton lot count • The trip distribution for East Ronton • The total trips contributed to the intersection of SR 900.148'h Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P300B), East Renton (L02P0005), Shamrock (L02P00141, Rosemonte (aka lronwood- L03P0018), Martin (L05P0019) and any future land use applications submitted to King County for Which compliance with the King County Intersection Standards (KCC 14.80) is requlreg at either the SR 900/148'h Avo intersection, orthe SR 9001164' Ave High Accident Location. In the event that oither King County or WSDOT adopts a formal ~Ialacomer's" system prior to final plat recording, that system may be fOl!owed in lieu of the approach doscribed above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection fmprovements will be installed within two years of the dale of rocording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21A.28.060A] 2. Documentation shall be provided to demonstrate to the satisfaction of WSDOT that stop~ing sight distance (360 feet) is availablo on tha east leg of the SR 900/148 1 Ave Intersoction. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition,.the app~cant shall clear vegetation within the right-of-way along SR 900, east of 148' Ave., to maximize the entering sight distance for the north and south legs of the Intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy 1-303 and King County Code 21A.2B.060A] An"environmental impact statement (EIS) was not required as a result of issuing"" the MDNS. The appeal period for the revised threshold determination ends at the. close of business on January 22,2007. The specific mitigation measures have baen incorporated as part of the applicant's proposal and are included in the list of recommended conditions of preliminary approval. Agoncies, affected Native American tribes and the public are offered the opportunity to comment on or appeal the determination until January 22, 2007. FILE NO L02P0005 Page 3 · , E. AGENCIES CONTACTED: 1. King County Department of Natural Resources and Parks: Comments are incorporated in the discussion in this report regarding wildlife, 2. King County Fire Protection Engineer: Fire protection engineering preliminary approval has been granted subject to the standard code requirements and requirement for sprinkloring of homos unless higher standards for road improvements are met. 3. Issaquah School District: The comments from this dislrlct have been incorporated into this report. 4. King County Waler Dislrict #90: The comments from this district have been incorporated into this report. 5. City of Renton (sewer pmvlder): See Attachmont 2. 6. METRO: No response. 7. Washington State Department of Ecology: No response. 8. Washinglon State Department of Fish and Wildlife: No response. 9. Washington State Department of Natural Resources: No Response 10. Washington Stale Department of Transportation: The comments from WSDOT have boon incorporated into the SEPA TD and in this report. F. NATURAL ENVIRONMENT: 1. Topography: The site slopes from east down to th 8 west with an overall elevation change of approximatoly 60 feet across the site with 20-30 percent slopes on the central 1/3rd of the site. 2. Soils: Two types of surfaces soils are found on this site per King County Soil SUNOY, 1973. a. The east 2/3rds of the site is classified as AgD -Alderwood gravely, sandy loam; 15-30% slopes. Runoff Is medium and the erosion hazard Is severe. This soil has a severe limitatlon for foundations due to slope, and a moderate s!Jppage potential. It has severe limitations for septic tank filter fields due to very slow permeability In the substratum. b. The west 1/3" of the site is classified as AgB -Aldenwood gravely, sandy loam; 0-6% slopes. Runoff is slow and the erosion hazard is slight. This soil type has a moderate limitation for low building foundations due to a seasonally high water table, and severe limitations for septic tank filter fields due to very slow permeabllily in the substratum. SoU exploration was preformed by Assoclated Earth ScIences, Inc. in April of 2001 and Technical Memorandum, dated September 24,2002 indicates slopes 15 % or over are moderately susceptible to erasion, however they concluded is that with the design of the outfall tho storm waler flows will not be susceptible to erosion. 3. Wetland/streams: A wetland/and or stream report was prepared by C. Gary Schultz dated April 3, 2001 and revised September 12, 2002. The wellands (A, B & C) are classified together as Class 2 Wetlands. These wetlands are part of a weIland system exceeding one acre in size and include forested area as the headwaters of Honey Creek. Some buffer averaging Is proposed along the east side of the on-site wetland. FILE NO L02P0005 Page 4 While this subdivision as presented has been determined to comply with sensitive area provisions, the adjoining plat of Rosemonte currently as designed will either need to shift tho street east so that the retaining wall is outside of the BSBL (this would change the street alignment of 145'h Ave SE) or instead propose additional buffer av~raging in Rosemonte to allow the BSBL to be shiftell west. According to the Conservation District maps, the site is characterized by a high water table. . The sl~e lies within the Honey Creek subbasin of the May Creek drainage basin. 4. . Vegetation: The west third of the site is heavily wooded with a second and third-growth mixture of coniFerous and broad-Ieafod trees native to the Pacific Northwest. Within the wetland Itself, there is predominalely Red Alder. Tt19 remaining portion of the site (east 2/3rds) Is primarily covered in pasture grasses. Scattered evergreen/deciduous trees and brush occur in limited numbers. ' 5. Wildlife: Two Red Toll Hawk Nests were identified back in 2001 wilh the central one determined to be abandoned and the northerly one activo. The applicant has proposed on the most recent plat plan location of lots at a minimum of 250 feet from the nest. Such birds are not listed as 1hreatened or endangerod species nor are they protected in the Urban area of King County. Other small birds and animals undoubtedly inhabit this site; and larger species may visit thIs site on occasion, however, the population of specie:::; is limited due to increased nearby development. . 6. Mapped Sensitive Areas: The Sensitive Areas Map Folio indic.ates that there is a wetland which crOsses over from this property onto the property to the north and south. G. NEtGHBORHOOD CHARACTERISTICS: The property lies In southeast King County, north of lhe City of Renton on the west side of 148Ui Avo SE which provides arterial access to tho site. Tile site is designatod as Urban and is within the urban growth boundary. In recent years there have been numerous plats in the local area approved by King County_ This East Renton area is in transit10n from a rural residential area to a low to medium density urban setting, On this site there Is an existing residence and detached garage and the remaining upland portion is manly In pasture: The forested area on the wost third is the lowest portion of the site and contains the wetland noted In this report. This property and other surrounding properly In the Urban area are zoned R-4 (Residential-4 du's per acre). Properties easl of 148'h Ave SE and'norlh of SE 120~ St. are zoned RA-5 (Rural Area -1 du per 5 acres). Additionally, these properties are outside the Urban Growth Boundary. 148'h AveSE is a 60 foot public right-of way and the right-ai-way is within the Urban Growth Boundary. H. SUBDIVISION DESIGN FEATURES: 1. Lot Pattern and Density:' The proposed lot and street layout is in conformance . with King County Codes (i.e. KCC 21A and the 1993 King County Road Standards. Density calculation for the plat average Is 3.9 d.u.'s per acre based on total acreage of 17.01 acres. Code would allow 68 lots under the base density provisions. Minimum density code provisions requIre development of at least 35 lots. Density of the net buildable area of 11,88 acres would be 5.6 dwelling units per acre. Th.9 66 lots are . generally 5,000 square feet in area and have a width typically of 50 feet. See Allachment 6 for thE> Density & Dimension Calculation Worksheet for further details. Additionelly, Tract E a future growth developmenllracl is proposed between wetlands on the lar west potion of the property. This tract is 48,128 square feet in size and is FILE NO LD2PD005 Page 5 almost totally surrounded by sensitive area/wetlands except on the south tract boundary which 81so is the south properly line of the plat. Future development of Ihis tract would be suuject to Critical An~a Code requirements which could require additional property be set aside as buffers. 2. Internal Circulation: Lots will front onto the internal public streets that provide access within the subdivision and exits out to 1401h Ave SE. Additionally street stubs connections are planned which would provide access to properties both north (145~ and 147 1h Ave SE) and south (145 1h AveSE). See the proposed plat layout. Attachment 1 to this rcport. The applicant has stated that the future development tract CQuid be served with access from the southerly aburting property. however though preapplicatlon review of the abutling parcol, it appears access to the proposed future development Irecl on East Renton could not be provided due to the extent o(wellands to the south on the o abutting parcel when applying code limitations of KCC 21A.24. . 3. Roadway Section: As proposed by the applicant. 148~ Ave SE frontage will be improved \A.'ith urban'impravements, Including curb, gutter, and sidewalks. A road variance was approved allowing an alternative design for Improvement (see AtI~chment 3. The internal public street planned as SE 1191h SI. will be improved 35 a subGoliector street, as will tile proposed 145~ Ave SE from SE 119'" 10 the south property line. SE 1201/1 81 and 147u1 Ave SE south of SE 119111 St will function as a subaccess street and 1461h Avs'SE will be' a minor access. 4. Drainage: The proposed subdivision Includes an underground storm water vault located within Tract G shown on the preliminary plat. Since the drainage facility will be located below ground, the surface area will be utilized as a recreation space for the future homeowners. A portion of the subdivision drains northerly to the property currently proposed for developmenl as the Rosemonte subdivision. Since the King County drainage manual requires storm water to be discharged at the naturaillocatlon, the applicant requested a drainage adjustment to divert storm water from the northern portion of tho sito to the proposed storm vault. This adjustment was approved' by King County in 2002; however, the applicant revised tho proposed drainage plan in 2003 after the adjacent parcel of land was proposed for development as the Rosemont subdivision. The current drainage plan shows an offsite delentlon pond located within Rosemonte which is designed to accommodate drainage for.Rosemonte and the northern portion of East Renton. To allow an ollsile drainage facility, the ap~licant requested approval for a second drainage adjustment to allow a shared facility for bolh subdivisions. As shown on the preliminary plat map for Rosemonte, a deteption pond is proposed within Tract C (per 3/8/06 revised plan) which will provide designs for flow control and water quality treatment. The dralnago adjustments for the original diversion and the subsequent adjustment for a shared facility are both shown in the staff report as 'Attachments 4 and 5. . In accordance with the 1998 King County drainage manual, the drainage fadiities will be designed for Level 1 flow control and basic water quality treatment. Tho site is located within the Honey Creek subbasin which drains to the targer May Creek watershed. The King County basin plan for May Creek has evaluated the Honey Creek basin and recommends that future development in this area use the level one flow control slandard as shown In the drainege manual. A review 01 the downstream corridor in the immediate vicinity of the project did not identify any specific drainage problems. After construction and acceptance of tho storm water vault and detention pond for the subdivisions, Ihe drainage facilities will be maintained in the future by King County. FILE NO L02P0005 Page 6 I. TRANSPORTATION PLANS: 1. Transportalion Plans: The King County Transportation Plan indicates that 148~ Avenue Southeast (adjoining east boundary) is doslgnated as a collector arterial. The King County Non-motorized Transportation Plan indicates 14alh Avenue Southoast as part of the plan and is to accommodato bicycles as a shared roadway. 2. Subdivision Access: The East Renton subdivision will provido urban road improvements with curb, gutter, and sidewalk for both the internal roads and frontage improvements along 148 1t1 Ave SE. During preliminary 'review of the roadways, King County determined that the existing crest vertical curve along 148111 Ave SE did not meel design slandards for stopping sight distance. Due 10 the substandard road design and tho need for improvirig the property frontage, the applicant submitted a road variance application to evaluate design requirements for the roadway. As shown in Attachment 3, the road variande was approved by the King County Department of Transportation to allow reconstruction of the frontage road to provide 455 feet of stopping sight distance. To provide adequate walking conditions for sChool children, an offsite sidewalk will also be proVided along 148-Ave SE, extending northorly from the slto to an existing crosswalk at tho intersection of SE 117 tl1 Street. Due to the topography and existing road improvements near the crosswalk, the applicants design for the . sidewalk shows a rockery located outside the right-of-way on private property. The . applicant has contacted the property owner regarding acquisition of a road easement, however this property owner has not clarified in writing a willingness to negotiato to allow easement rights, therefore final resolution has not beon provided at this time. During fjnal engine~ring, the applicant will need to obtain an easement for construction on private property or prepare an alternative walkway design which satisfies the design requirements within the eXlsttng right-of-way. It is possible that the applicant could design improvements on the east side of 1481h that would meet the walkway reqUirements, as well. Access into the plat will be provided off 148~ Ave SE. The planned stub street to tho south may someday provide for a secondary access out to 148'h Ave SE. and will Improve the connoctivlty between subdivisions. 3. Traffic 0enerallon: It Is expecled thai approximately 660 vehicle trips per day will be generated with full development of the proposed subdivision. This'calculation' includes service vehicles (Le., mail dolivery, garbage pick~up, school bus) which may currently serve this neighborhood, as wen as work trips, shopping, etc. 4. Adequacy of Artorial Roads: This proposal has been reviewed under the criteria In King County Code 14.70, Transportation Concurrency Management; 14.80, Intersection Standards; and King County Code 14.75; Mitigation Payment System. a. King Counly Code 14.70 -Transportation Concurrency Management: The Transportation Certificate of Concurrency dated April 9, 2002, indicates that transportation improvements or strategies will be in place at tho time of development, or that a financial commitment Is In place to complete the improvements or strategies within six (6) years, according to RCW 36.70A.070(6). b. King County Code 14:80 -Intersection Standards: The existing arterial system requires Improvements to accommodate the increased traffic volume generated by this proposal. As a result, DDES issued a MDNS which calls for the mitigation needed to address the Impacts resulting from added traffic onto local intersections rather than requiring an EIS prior to action on the preliminary plat application, see Section D of this report. The appeal period for the Threshold Dolermination closes January 11, 2007. FILE NO L02P0005 Page 7 " c. King County Code 14.75 -Mitigation Payment System: King County Code 14.75, Mitigation Payment System (MPS), requires the payment of a traffic impact mitigation fee (MPS fee) and an administmtion fee for each single-family residential let or unit created. MPS fees are determined by the zone in which the site is located. This site is in Zone(s) 442 per the MPS/Quartersection list. MPS fees may be paid at tho time of final plat recording. or deferred unlll building permits are issued. The amount of the fee will be determined by the appticable fee ordlnanco at tho time the fee is collected. J. PUBLIC SERVICES: 1. Schools: This proposal has been reviewed under RCW 50.17.110 and King County Code 21A.20 (School Adequacy). a. School Facilities: Students from the proposed plats of East Renton and Rosemont will be served by Apello Elementary, Maywood Middle, and Liberty High School. As a result of the passage of time (nearly 5years between the April 2002/East Renton Request for School Information and the date of preparation of this staff report) following the receipt of the response from the District, the STC has reconfirmed the school service boundaries by checking the School District's web site, and the 'service area'/Attendance map pages for each of the applicable schools. b. School Impact Fees: Currontly the Issaquah School District required that an impact fee per lot be imposed to fund school system improvements to serve new development within this district. Payment of this fee in a manner consistent with K.C.C. 21A.43 will be a condition of subdivision approval. c. Schoot Access: Apollo Elementary School is located to the north of the subject subdivision, off of SE 117'" Street, east of 148" Avenue SE. According to information provided by the Issaquah School District, students of Ihis age group would be provided bus transportalion to Ihe school due to conditions along the walkway route unless sidewalk improvements would be provided along 148-Avenue SE (see Condition 12). The Subdivision Technical Committee (STC) has reccmmended that, in addition 10 the llrban shoulder improvements across the frontage ofths"proposed subdivision, that urban improvements be provided oeross the frontage of the abutting (and, relatod by ownership, access and required off-site mitigation) proposed plat of Rosemonte (FKA Ironwood), DOES Fila II L03P0016. The existing designated crossing across 148 lh Avenue SE is Idcated immediately off-frontage from the tlorthem subdivision "boundary of Rosemonte, therefore, the STC believes that additional improvements "-off-site to both plats' frontage -is necessary to provide adequate walkways for this age group. Such improvements should m~et tho urban standards for sidewalks and curbs due to location on the north side of the intersection, the need for a railing, and treffic volumes on 148" Ave SE. Additionally, due to the potential need to construct a curb and gutter section along the east side of 148'h Avenue SE (to ro-pr6fi1e 148-Avenue SE, and maintain the resultant slope grading within existing right-of-way), the STC recommends that if the project proponent elects to implement this option, that a graded surface be provided to ensure that school-age p.edestrians are provided an acceptable-width walkway surface behind the curbing. Maywood Middle School is located to the south of the proposed subdivision, on the opposIte side of Southeast 12Slh Street, in the 14400 block of 16S lh Avonue SE. Students of this age group are provided bus transportatiom to/from the school due to distance and the traffic conditions along any potential walking routes. The District had requested that a safe waiting area be provided at the intersection of Southeast 120~ StreeU14S'h AvenueSE. The STC recommends in the plat conditions that a level concrete 'pad' be constructed to augment the required sidewalk improvements aUnear the FILE NO L02P0005 Page 6 indicated intersection. See Condition S.h. This improvement will serve the middle and high school~aged residents of t;>oth the subject subdfvision and the proposed plat of Rosemonte. Liberty High School is localed to the south of the proposed subdivision, on tho opposite side of Soulheasl12S'" Sireet, in the 16600 block of Southeast 136'" Street. Studenls of Ihis age group are provided bus transportation to/from tho school due to distance and the traffic conditions along any potential walking routes. The Issaquah School District had requested, In its April 2002 response, that a safe waiting area be provided at the intersection of Southeast 120lh StreotJ14S lh Avenue SE. The STC recommends in the plat conditions that a level concrote 'pad' be constructed to augment the required sidewalk improvements aUnear the indicated intersection. See Condition B.h. This improvement will serve the middle and high school- aged residents of both tho subject subdivision and the proposed plat of Rosomonte. 2. Parks and Recreation Space: K.C.C. 21A.14 requ.ires subdivisions in the UR and R zone classifications to either provide on-site recreation space or pay a fee to the Parks Division for establishment and maintenance of neighborhood parks. At this time, it does not appear that tho applicant's plan will provide suitable recreation space as required by code. Additionally, thero are no nearby parks where a "foe in lieu" could be applied. In total 25,740 square feet of recreational area is required (390 square feet por lot). East Renton Tract C at the comer of 147~ Ave. SE. with SE 111" St. Indudes 9,335 sf and Tract G at the corner 145~ Ave. SE. with SE 11/'lh St. is shown to contain 16,407 ·sf. Togethertheso tracts equat 25,742 sf.: however all ofTract G currently does not fit the definition of flat, dry and usable area. With placement of a drainage vault on the tract. that recreation area on top the vault and any additional area in the tract contoured for recreational use (aU 5% slope or less) would be counted towards the total needed square footage. Staff estimates that the vaul1 has an 8,400 sf surfE\ce area and given the existing topography not all the remaining tract area could possibly be counted towards the total flat, dry, useable area due to topography beyond the tract. Attachment 7. shows the limiting factors in the cross section of an earlier configuration of Tract G (Iaboled Tract C). Options to comply with minimum area . would include adding additional area to either the current Tract C or Tract G. Staff would not be in support of creatIng a third tract for recreation, except if such tract W<lS connected to either Tract C or Tract G by trail (i.e. conversion of Tract E to recreation area minimally providing a trail). K.C.C. 21A.14.190 requires subdivisions to provide a toVchildren play area within tho rocreation space on site and two additional recreational facilities as listed in K.C.C. 21A.14.190 E.2. Staff would support a plan with at least one recreation facility on ono tract and two on the other tract. Both recroation tracts are located on tracts easily accessible to plat residonts. Tmcl C is near the plat entry on a comor so to provide good visibility and access. Tract Gis at a location that takes advantage of the views into the sensitive aroa (wotland) west . of the tract. Also the tract functions in providing storm detention. The request would not comply with all provisions of KCC 21.14.180 F. and therefore per code, KCC 21.14.180 C. applies to both recreation tracts. 3. Fire Protection: The Certificate of Water Availability from Water District # 90 Indicates that water will be available to the s~e in sufficient quantity to satisfy King County Fire Flow Standards, Prior to final recording of the plat, the water service facilities must be reviewed and approved per King County Fire Flow Standards. All future residences constructed within this subdivision are required to be sprinklered NFPA 130 unless the requirement is removed by the King County Fire FILE NO L02POD05 Page 9 . Marshal or his/her designee. The Fire Code requires all portions of the exterior walls of structures 10 be within 150 feet (as a person would walk via an approved route around the building) from a minimum 20~foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement drIving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. K. UTILITIES 1. Sewage Disposal: The applicant proposes to selVe lhe subjeet subdivision by public sewer of tho City of Renton. The City conditio nod the extension of sewer tu the reqUirement that the developer sign a covenant allowing for future annexation of the properly into the City. (Seo Attachment 2) .. 2. Water Supply: The applicant proposes to serve the subject subdivision from a public water supply and distribution system managed by Water and District # 90. A Certificate of Water Availability, dated April 4, 2004, indicates this district's capability to sOlVe the proposed de·velopment. Dedication of easemehls to the district for extension of water mains will be required. L. COMPREHENSIVE AND COMMUNITY PL&!i; 1. Comprehensive Plan: This plat is governed by tile 19,94 King County Comprohensive plan which designatos this area as Urban Residential 4-12 dwelling units· per aCrB. The. proposed subdivision is not in conflict with tile policies of the Comprehensive Plan. 2. CommunityPlans: The subject subdivision is located In the Newcastle Planning Area and does not conflict with the goals, guidelines, and policies of the Community Plan. M. STATUTES/CODES: If approved with the recommended conditions in this report, the proposed development will comply with the requirements of the Counly and State Platfing Codes and Statutes, and the lots in the proposed subdivision will comply with the minimum dimensional requirements of the zone district. N. CONCLUSIONS: 1. The subject subdivision will comply with the goals and objectives of the King County Comprehensive Plan and will comply with the reqUirements of the Subdivision and Zoning Codes and other official land use controls 6f King County, based on the conditions for final plat approval. 2. Beyond the typical plat reqUirements, conditions are proposed wt"!ich would require the applicant to provide design plans and documentation that addres$ the items below to the satisfaction of DOES: a. Acquisition of easements from private property owners with property adjacent to 148 'h Ave SE are needed to construct road improvements 10 148~ Ava SE. as proposed. Acquisitions includes an easement for a retaining wall to support sidewalk improvements to the existing crosswalk on the north side of at SE 117~ St., and from property owners on the east side of 148· Ave SE for side slope easements to support the planned profile/elevation change to 148· Ave SE. FILE NO L02P0005 Page 10 ~ " Urban road improvements on the west side of 148\h Ave SE along the property frontage ( and frontage of Rosemonte) north to the north side of SE 117~ St. will satisfy the need for safe walkway access to the school. Should the applicant be unable to obtain easements, urban road improvements could feasibly be provided on the east side of 148~ Avo SE as a means to elim1nate the need for slope easements on the east side of the road and provide an altornative for a safe walking to the school. b, As designed, the plat does not provido for sufficient area to meet code minimum for recreation area. As a means to enlarge either Tract C and/or G, lots proposed could be reduced in size, if needed, and still ccmply with the minimum standards for size and width without lose of density. Revision t6 the plat design will be needed to adjust the size recreation area . tract(s) to meet code minl'mum for recreatlonal area. c. Tract E (proposed as a future development tract) can not under all reasonable scenarios actually be developed for lots in the future. When development of the south abutting property occurs, access from the south will unlikely be proposed. Such access would require croSSing wetland and/or buffer on abutting property that Is not allowod by the code criteria for critical areas in KCC 21A.24. Alternativoly, staff would support adding Tract E: 1) into the sensitive area 1ract surroundi"ng, 2) designating the tract as open space, or 3) designing the tract as recreational area, if served by traIl extending from the recreational Tract G to Tract E, whereby Tract E would function as an extension of recreation from Tract G .. d. Buffer averaging is the preferred alternative to assure the retaining wallin Rosemonte'off 145tl1 Ave SE is outsido of the wetland buffer and BSBL. Should buffer averaging not· provide complete relief from buffer and EiSBL limitations, then 145" Ave SE nius! be shiftod east. Allgnmont of 1451h Ave SE within East Renton and within Rosemonto should be coordinated to assure a workable [:Ilignment of 145 111 Ave SE for the two plats. O. RECOMMENDATIONS: It is recommended that the subject subdivision's East Renton Preliminary Plat Page 1, revised and received March 17, 2006, be granted preliminary approval subject to the" following reVisions to the plat design and conditions of final approval: 1. 2. 3. Compliance with all platting provisions of Title 1 9A of the King County Code. All persons having an ownership interest in the subject property shall sign on the face of the final plat a dedication that includes the language set forth in King County Council Motio'n No. 5952. The plat shall comply with the base density and minimum density requirements of the R·4 zone classification. All lots shall meet the minimum dimensional requirements of the R-4 zone classification or shall be shown on the face of the approved prelirnlnary plat, whichever is larger, except that minor revisions to the plot Which do not result In substantial changes rnay be approved at the discretion of tho Departrnent of Development and Environment Services" Any/all plat boundary discrepancy shall be resolved to the satisfaction of DDES prior to the submittal of the final plat documents. As used in this condition, "discrepancy" is a boundary hiatus, an overlapping boundary or a physical appurtemmce which Indicates an encroachment, lines of possession or a conflict of title. FILE NO L02P0005 Page 11 4. 5. 6. 7. Tho applicant must obtain final approval from the King County Health Department. All construction and upgrading of public and private roads shall be dono in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). The applicant must obtain the approval of the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the King County Qodo. Acfd.-,' hOYt d'-/ I2nzd u)·d-ih. Final plat approval sha{require full compliance with tho drainage provisions sot forth in King County Code 9.04. Compliance may result in reducing the number and/or location of lots as shown on the preliminary approved plat. Preliminary review has identified the following conditions of approval, which represent portions of the drainage reqUirements. All other applicable roqulrements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual. DOES approval olthe drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DOES Engineering Review shall be shown'on the engineering plans. c. Tho following nota· shall be shown on the nnal recordad plat: "All building downspouts, footing drains, and drains from all impelVlous surfaces such as patiOS and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DOES andlor the Department ofTransportation. This plan shall be submlttad with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for Individual lot infiltration systems, the systems shall be constructed afthe tim a of the building permit and shall comply with the plans on file." . d. Storm water facilities shall ba dasigned using tha KCRTS level one flow control standard. Water quality facilities shall also be provided using the basic water quality protection menu. Tho sIze of the proposod draInage tracts may have 10 increaso to accommodate the requirod detention volumes and vyater quality facillties. All runoff control facilities shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for recreation space in accordance with KCC 21A.14.180. . e. The applicant has received approval for two drainage adjustment applications regarding designs for the discharge of storm water and a shared facility detention pond. The adjustment decisions are contained within file numbers L02VOOS9 and L04V01 03. During final review of the engineering plans, all applicable conditions of the adjustment approvals shall be satisfied including requiraments for the shared facility located offsite within the plat of Rosemonte. f. As stated in the drainage adjustment decision, the offsite drainage pond shall be designed using tha Level 1 flow control standard. Basic water quality standards are also required for design of the facility. If a wet pond facilily is providad for water quality, the design shall comply with the 3:1 flow length ratio as outlined on page 6-72 in the drainage manual. For evaluation of the onsite storm vault and the offsite detention pond, a soils FILE NO L02P0005 Page 12 report shall be prepared be a geotechnical engineer to evaluate the sqlls and groundwater conditions. g. For any proposed bypass of storm water from the flow control facility, the final drainage designs shall comply with applicable design requirements in the drainage manual as outlined on pages 1-36 and 3-52. h. As required by Special Requirement No.2 in the drainage manual, tho 1 OO-year floodplain boundarios for the onsite wetlands shelll be shown on the final enginooring plans and recorded plat. Access and Roads 8. The proposed subdivision shall comply with the 1993 King County Road Standards (KCRS) including the following requirements: 8. During preliminary review the applicant submitted a roeld variance application (File No. L03V0049), regarding the crest vertical curve and substandard stopping sight distance along the plat frontage. In response to tho variance application, the King County Road Engineer provided a decision letter dated October 20, 2004 which approved the varianco based upon spocific design criteria for constructing 148lh Ave SE. As noted in the variance decision, the crest curve on 148lh Ave SE must be reconstructed to provide 455 feet of stopping sight distance based upon design criteria with a 2-foot target. The final road improvements and design plans for the project shall demonstrate compliance with all applicable conditions of approval as stated in the variance decision. b. 148111 Avenue SE shall be improved along the frontage as an urban collector arterial inclu9ing all desig~ criteria from the road variance decision. In accordance with KCRS 2.02, the curb loeation shall be designed at 22- feGt from tho road crown to' provide full width travel lanes and a bike lane. The preliminary dosign plans for East Renton shows road grading extending outside the right-of-way on the east side of 1481h Ave SE. During final ongineering review, the applicant shall acquire e~sem~nts for flny proposed construction on prlvate property or provide an alternatlve design which is acceptable to King County for road construction within the existing right-of- way. c. The project entry road 10 1481h Ave SE shall be improved as an urban neighborhood colleCtor. As s!lown on the preliminary plat, the required right-aI-way width Is 56 feet d. The proposed roads within the subdivision shall bo improvod using urban design standards and in accordance with the street classifications shown on tho preliminary plat map . . 9. Tract 0 shall be improved as a private joint use driveway serving a maxImum of two lots. The serving lots shall have undivided ownership of the tract and be responsible for its maintenance. As specified in KCRS 3.Die, Improvements shall inclu·de an 18 foot paved surface and a minimum tract width 01 20 feet. Drainage control shall Include a curb or thickened edg~ on One side. f. Street trees shall be included in the design of all road improvements and shall comply with Section 5.03 of the KCRS. g. Street illumination shall be provided along the plat frontage and at Intersections with arterials in accordance with KCRS 5.05. FILE NO L02P0005 Pago 13 h. The proposed road improvements shall address the requirements for road surfacing outlined in KCRS Chapter 4. As noted in section 4.01 F. full width pavement overlay is required where widening existing asphalt, unless otherwise approved by King County. i. 148 lh Avo SE is classified an arterial street which may require designs for bus zones and turn outs. As specified in KCRS 2.16. the designer shall contact Metro and tho local school district to determine specific requirements. j. Modificatie:>ns to the above road conditions may be. considered by King County pursuant to the variance procedures in KCRS 1.08. 9. All utilities within proposed rights·of·way must be included within a franchise approved by the King County Council prior to final plat recording. 10. The site plans for East Renton show the northerly road stub for 145'h Ave SE which may extend into the wetland buffer and associated setback within the Rosemont plat. During engineering review for East Renton, a revised road alignment and grading plan shall be provided which demonstrates. that road construction wllhln Rosemonte will comply with applicable sensitive area codes. The revised road design and grading plan may result In modiflcatidn or loss of lots as shown on the preliminary plat. Alternatively, the appllcant may seek approval to use buffer aver?ging as a means to revise tho location of the buffer and BSLB to achieve code compJiance within Rosemonte. 11. There shall be no direct vehicular access to or from 148'" Ave SE from thosa lots which abut it. A note to this effect shail appear on the engineering plans and the final plat. 12. The applicant shall provide a safe walking access to Apollo Elementary School with urban improvements along the west side of 148111 Ave NE.to the existing crosswalk on the north side of SE 117'" St. This improvement includes urban frontage improvemants along property frontage of the Plat of East Renton, urban 'improvements along frontage of Rosemonte and urban improvements north to the existing crosswalk on the north side of SE 11 ih ST. (It is noted that the adjoining plat of Rosemonte will be subject to urban frontage requirements and urban improvements north to the existing crosswalk on the n"rth side of SE 117-ST.) Alternatively, due to the potential need to construct an urban curb and~ guller section along the east side of 148 th Avenue SE (to re-profile 1481h Avenue SE, and maintain the rosultant slope grading within existing rlght-of·way), ~he applicant may elect to provide a graded surface on the east side of 1481h Avo SE to ensure that school·age pedestrians are provided an accaptable.width walkway surfaca behind the curbing. The walkway shall be designed to the satisfaction of the school district and DOES. MltJgatJonlimpact Fees 13. The applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either: (1) pay the MPS fee at the final plat recording, or (2) pay the MPS fee at the time of building penmit issuance. If the first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All leas required by King County Code 14.75, Mitigation Payment System FILE NO L02POOOS Page 14 (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building pennit application. 14. Lots within this subdivision are subject to King County Code 21A43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shall be assessed and collocted immediately prior to the recording, u3ing the fee schedules in effect when the plat receives finnl approval. The balance of the assessed fee shall be allocated evonly to the dwelling units in the plat and shall be collected prior to building permit Issuance. Wetlands 15. Preliminary plat review has identified specific requirements which apply to this project as listed below. All other applicable requirements from K.C.C. 21A.24 shall also be addressod by the applicant a. The Class 2 wetland shall have a minimum 50-foot buffer of undisturbed vegetation as measured from tho wetland edge. b, Sensitive area tract(s) shall be usod to delineate and protect sensitive areas and buff~rs in development proposals for subdivisions and shall be recorded on all documents of title of record for all affected lots. c. Buffer width averaging may be allowed by King County if it will provide additional protection to the wetland/stream or enhance there functions, as long as the total area"contained in the buffer on the development proposal site does not decrease. In no area shall tho buffer be less than 65 percent of the required minimum distance. To ensure such functions are enhanced a mitigation plan will be required for the remaining on-site sensitive areas. An enhancement plan shall be submitted for review during engineering review. d. A 15-foot BSBL shall be established from the odge of buffer andlor the sensitive areas Tract(s) and shown on all affected lots. e. To ensure long term protection of the Sensitive Areas a split-railed fence of no more than 4 foet in height shall be Installed along the Sensitive Area Tract boundaries In the area of proposed lots. Sensitive Area· signs shall be attached to the fence at no less than 100 foot inteNals. f. If alterations of streams and/or wetlands are approved in conformance with K.C.C. 21A.24, then a detailed plan to mitigate for impacts from that alteration will be required to be roviowed and approved along with ·the plat engineering plans. A performance bond or ather financial guarantee will be required at the time of plan approval to guarantee that the mitigation measures are installed according to the plan. Once the mitigation work Is completed to a DDES Senior Ecologist's satisfaction, the performance bond may be replaced by a maintenance bond for the . remainder of the five-year monitoring period to guarantee the success of the mitigation. The applicant shall be responsible for the installation, maintenance and monitoring of any approved mitigation. Themitigation plan must be installed prior to final inspection of the plat. g. Prior to commencing construction activities on the site, the applicant shall temporarily mark sensitive areas tract(s) in a highly visible manner, and these areas must remain so marked until all development proposal activities In the vicinity of the sensitive areas are completed. FILE NO L02P0005 Page 15 h. During engineering plat review tile applicant shall provide a wetland hydrology analysis to, demonstrate how tho wetland hydrology will be maintained post-construction. i. Detention out-Iall structures maybe permitted within the wetland/stream buffers, however, structures shall be located in the outer edge 01 the buffer, If possible. All buffer impacts shall be mitigated. 16. Development authorized by this approval may require other state and/or federal permits or approvals. It is the applicant's responsibility to correspond with these agendes prior to beginning work on the site. 17. During engineering review, the plan set shall be routed to the sensitive areas group to determine jf the above conditions have been met. Geotechnical 18. The applicant shall delineate all on-site erosion hazard areas on the tinal engineering plans (erosion hazard areas are defined in KCC 21A06.415). The delineation of such areas shall be approved by a DDES geologist. The requirements found in KeC 21A.24,220 concerning erosion hazard areas shall be met, including seasonal restrictions on clearing and grading activities. Sensitive Area 19. The lollowing note shall be shown on the final engineering plan and recorded plat: RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tract/sensitive area and buffer conveys to the public a beneficial interest in tho land within the tracVsensitive area and buffer. This interest includes tho preservation of native vegetation for all purposes that benefit the public. health, safety and welfare, including control of surface water and erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tract/sensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tracVsensitive area and buffer the obligation, enforceable on bellalf of the public by King County, to leave undislu"rbed all trees and other vogetation within the tracUsensitive area and _buffer. The vegetation within the tracVsensltive area and buffer may not be cut, pruned. covered by fill. removed or damaged without approval in writing from the King County Department of Dovelopment and EnvIronmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tracVsensltlve area and buffer and the area of . development activity must be marked or otherwIse flagged to the satisfaction of King County prior to anY,clearing. grading. building construction or other development ac1ivity on a lot subject to the sensitive area tracUsonsitive area and buffer. The required marking or fiagging shall remain In place until all development proposal activitIes in the vicinIty of the sensitive area are completed. No building foundations are allowed beyond tho required 15-loot building setback line, unless otherwise provided by law.· FILE NO L02P0005. Page 15 Other 20. The plat design shall be revised to provide the minimum suilable recroation space consistent with the requirements of K.C.C. 21A.14.1BO and K.C.C. 21A. 14.190 (i.e., minimum area, as well as, sport court[s], children's play equipment, picnic table[s], benches, etc.). a. A detailed recreation space plan (i.e .. location, area calculations, dimensions, landscape specs, oquipment specs, etc.) shall bo submitted for review and approval by DDES prior to or concurrent with the submittal of engineering plats. . b. A performance bond for recreation space improvements shall be postod prior to recording of the plat. 21. Tract E shall be revised as a tract which is: a) combined with Track F . (sensitive area), b) designated as an open space tract, or, c) designated as recreational area, ~ served by an approved trail (across wetland buffers) extending from the recreational Tract G and functioning as an extension of recroation from Tract G. Plans for the tract -designation and design, shall comply with codos and 3hall be to tho satisfaction of DOES prior to engineering approval. 22. A homeowners' association.or other workable organization shall be established to the satisfaction of ODES which provides for the ownership and continued maintenance of the recreation. open space andlor sensitive area t~act(s). 23. Street troos shall be provided as follows (per KCRS 5.03 and K.C.C. 21A.16.050): a. Trees shaH be planted at a rate of one tree for every 40 feet of frontago along all roads. Spacing may be modified to ·accommodate slgllt distance requirements for driveways and intersections. b. Trees shall be located within the straet right-aI-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards. unless King County Oeparbnent of Transportation determines that trees should not be located In the street right-aI-way. c. If King County determines that the required street trees should not be located within tho right-aI-way, they shall be located no more than 20 feet from the street right-of-way line. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the . county has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DOES if located withIn lhe right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing treas, or any other tree or shrub whose roots are likely to obstruct sanitary or storm sewers, or that Is not compatible with overhead utility lines. f. The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DDES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at (206) 684-1622 to determine if 148lh Ave SE·is on a bus route. If 148 1h Avo SE is a bus route, the street tree plan shall al.so be roviowed by Metro. FILE NO L02P0005 . Page 17 SEPA h. The street trees must be installed and inspected, or a performance bond posted prior to recording of the plat. If a performance bond is posted, the street trees must be installed and inspected within one year of recording of tho plat. At the time of inspection, if the trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year, After one year, the maintenance bond may be released after DOES has completed a second inspection and determined that the trees have been kept h~althy and thriving. i. A landscape inspection fee shall also be submitted prior to plat recording, The inspection fee Is subjoct to change based on the current county fees, 24. The following have been established by SEPA as necessary requirements to mitigate tho adverse environmental Impacts of this development. The applicants shall demonstrate compliance with these Items prior to final approval. (1,) To mitigate the significant adverse impact the plat of East Renton will have on the Intersections of SR 900/148lh Ave SE and SR 900/164 ti ) Ave SE, the applicant shall install, either hidividually or in conjunction with other development proJects in this area, the following improyements at the SR 9001148 10 Ave intersection: • A traffic Signal, and • Eastbound and westbound left turn lanes The design for the SR 900/148"' Ave intersection improvements shall .be approved by the Washington State Department of Transportation (an~ by King County to the extent such improvements are located in County right-ol- way). In additi.on, at a minimum, the existing entering sight distance l<!laking east for the north and south legs of the intersection (602 feet and 386.feet, respectively) shall not be reducsd as part of the intersection Improvements. Documentation shall be submitted to show this requirement Is met. All con,struction work associated with the hitersectl~n improvements shall be completed between April 1'1 and· September 30 1 . This seasonal rostriction · shall be clearly 'shown on the final engineering plans. ' In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantee with WSDOT which assures tho Installation of these improvements within two years of the recording of East Ronton. In this event, intersection Improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to th.e recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the lmprovements ·or "bonded" for the improvements, in an amount proportional to the Impa~ts of East Renton, The pro-rata share dollar amount to be paid shall be set by . WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording, The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip .distribution for East Renton . • The total trips contributed to the intersection of SR 900.148~ Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P3008), East Renton (L02P0005), Shamrock (L02P0014), Rosemonte (aka Ironwood- L03P0018), Martin (L05P0019) and any future land Use applications FILE NO L02POOOS Pag.e 18 submitted to King County for which compliance with the King County Intersection Standards (KCC 14.80) is requireg at oitller the SR 900/148'" Ave Interseetion, or the SR 900/164 Avo High Accident Location. In the event that oither King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu of the approach described above, at the discretlon of the applicant. as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years of tho dale of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21A.28.060A] (2.) Documentation shall be provided to demonstrate to 1I1e satisfaction of WSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900/148 1h Ave intersection. The intersection shall be modified by the applicant, if necessary. so that this stopping sight dIstance requirement is met on the east leg. In addition, the applicant shall clear vegetation within tho right-of-way along SR 900, east of 1481h Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprohensive Policy . T-303 and King County Code 21A.2B.06bA] Q. OTHER CONSIDERATIONS: 1. The subdivision shall conform to K.C.C. 16.82 relating to grading on private property. 2. Development of the subject property mny require registration with the Washington State Department of licensing, Real Estate Division. 3. Preliminary approval of this application does not limit the applicant's responsibility to obtain any required permit or license from the State or other regutatory body. This may Include, but is not limited to the following: a. Forest Practice Permit from the Washington State Department of Natural Resources. b. National Pollutant Discharge.Elimination System (NPDES) Penmit from WSDOE. c. Water Quality Modification Permit from W8DOE. d. Water Quality Certification (401) Permit from U.S. Army Corps of Engineers. R. ATTACHMENTS: 1. Preliminary Plat Map 2. Renton Sewer Availability letter 3. Road Variancel L03V0049 4. Surface Water Management Variancel L02V0089 5. Surface Water Management Variancel L04V0103 6. Density CalCUlation Worksheet 7. Recreation cross section for Tract G (previously labeled Tract C) FILE NO L02P0005 Page 19 ------------------------------ King County Department of Development and Environmental Services REVISED State Environmental Policy Act (SEPA) Mitigated Determination of Nonsignificance for East Rentonl L02P0005 Date of Revised Issuance: December 29,2006 Date of Issuance: December 15, 2006 Project: Location: Applicant/Contact: King County Contact: . King County Permits: This is a request for a subdivision of 17.01 acres into 66 lots for detached single·family dwellings. The proposed density is 3.9 dwelling units per acre. The lot sizes are predominately 5,000 square feet. West of 148th Ave SE at approximately SE 120th St. Camwest Real Estate Development, Inc. 9720 NE 120th Place, Suite 100 Kirkland, WA 98034 Contact: Sara Slatten Phone # 425-825·1955 Karen Scharer, Project/Program Manager II Phone # 206·296·7114 or email at karen.scharer@metrokc.gov Formal Subdivision Existing Zoning: R-4 Community Plan: Newcastle Basin: May.Creek Section/Township/Range: 10·23·05 Parcel # 1023059023 Notes: The mitigations have been revised to reference the subject plat of East Renton rather than the previous incorrect reference to other plats. A. This finding is based on review of the site plan showing the revised proposed development received 3/17112006, SEPA Environmental Checklists, dated 4/3/2002, Revised Level 1 Downstream Analysis by Triad & Assoc., dated 11/24/2004, Traffic Impact Analysis by Garry Struthers Associates, Inc., received 4/3/2002, Garry Struthers Memorandum dated 1/23/2003, WSDOT correspondence of 2127/2003 and 3/14/2003, Certificate of Water Availability, dated 4/412002. Certificate of Sewer Availability, dated 3/28/2002, Revised Wetlands Study with wildlife habitat study by C. Gary Schulz dated 07/28/2005. B. Issuance of this threshold determination does not constitute approval of the formal subdivision. The application will be reviewed for compliance with all applicable King Counly Comprehensive Plan Policies and King County Codes which regulate development activities, including the Uniform Fire and Road Standards, Surface Water Design Manual. and the Sensitive Areas Regulations. C. The Residential designation on the Land Use Map of the King County Comprehensive Plan allows for the proposed density. Additionally, this density is within the range per the R-4 Zone. The plat with 66 lots would yield an average density of 3.9 dwellings per acre (based on the site area). The lots will mostly be 50 feet by 100-105 feet with about 5,000 square feet. L02P00051 REVISED SEPA TO December 29, 2006 . Page 2 D. SWM Adjustment L04V0103 was approved 3124105 for a shared facility concept allowing the northeast corner of East Renton to utilize the eastern drainage facility in Rosemonte, the proposed plat immediately north of the subject property. E. The subject property is located southwest of the intersection of State Route 900 and 148'" Ave. SE. According to the applicant's traffic analysis, this intersection will operate at Level-of- Service "F" following the development of the proposed plat (unless improvements to the intersection are made). Per the applicant's traffic analysis, approximately 51% of the P.M. peak hour trips from the proposed plat will pass through this intersection. The proposed plat will have a significant adverse impact on this intersection per KCC 14.80.030. F. A horizontal curve exists on the east leg of the SR 9001148 th Ave SE intersection. Based on data provided by the traffic engineer for the plat of Shamrock, which was reviewed by the Washington State Department of Transportation (WSDOT), the available stopping sight distance on the east leg of the intersection meets the standards of the Washington State Highway Design Manual. G. WSDOT has concluded that, based on turn lane warrants from the Washington State Highway Design Manual, eastbound and westbound left turn lanes should be constructed on SR 900 at the 148th Ave. intersection. The proposed plat will add vehicular trips to the hazardous westbound left turn movement at this intersection. H. In order to address traffic impacts from the proposed plat, WSDOT has requested that the applicant (along with other development projects that will contribute traffic to the SR 9001146'h Ave. intersection) improve this intersection with a traffic signal and eastbound and westbound left turn lanes. I. The intersection of SR 9001164'h Ave SE is located approximately one mile east of the subject property. This intersection of SR 9001164'h Ave SE. is located approximately one mile east of the subject property. This intersection has been identified by WSDOT as a High Accident Location, and lies within a High Accident Corridor. The subject plat will contribute approximately 10 peak hour trips to this intersection and WSDOT and the King County Department of Transportation have concluded that the subject plat will have a Significant adverse impact at the intersection. The installation of a traffic signal at the 1481h Ave. SEISR 900 intersection will mitigate the impact of the proposed plat on the 1641h Ave. intersection, by diverting traffic away from the 164 1h intersection to the 1481h intersection, where following signalization, certain turning movements can be made more safety, J. King County Road Engineer reviewed and granted road variance approval on 1012012004 for Road Variance L03V0049 the variance approved approval was for a 620 -foot vertical curve with 455 feet of stopping sight distance, utilizing a two-foot target. Additionally approved is the slight grade break (under 1 %.) at the north end of the vertical curve. Threshold Determination The responsible official finds that the above described proposal does not pose a probable significant adverse impact to the environment, provided the mitigation measures listed below are applied as conditions of permit issuance. This finding is made pursuant to RCW 43.21 C, KCC 20.44 and WAC 197-11 after reviewing the environmental checklist and other information on file with the lead agency and considering mitigation measures which the agency or the applicant will implement as part of the proposal. The responsible official finds this information reasonably sufficient to evaluate the environmental impact of this proposal. Mitigation List The following mitigation measures shall be attached as conditions of permit issuance. These mitigation measures are consistent with policies, plans, rules, or regulations designated by KCC 20.44.080 as a basis for the exercise of substantive authority and in effect when this L02P0005 1 REVISED SEPA TD December 29, 2006 Page 3 threshold determination is issued. Key sources of substantive authority for each mitigation . measure are in parentheses; however, other sources of substantive authority may exist but are not expressly listed. 1. To mitigate the significant adverse impact the plat of East Renton will have on the intersections of SR 9001148 1h Ave SE and SR 900/164 1h Ave SE. the applicant shall install. either individually or in conjunction with other development projects in this area. the following improvements at the SR 900/148 1h Ave intersection: • A traffic signal. and • Eastbound and westbound left turn lanes The design for the SR 900/148 1h Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by King County to the extent such improvements are located in County right-of-way). In addition. at a minimum. the eXisting entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet. respectively) shall not be reduced as part of the intersection improvements. Documentation shall be submitted to show this requirement is met. All construction work associated with the intersection improvements shall be completed between April 1 ,I and September 30 1h • This seasonal restriction shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval. the applicant may post a financial guarantee with WSDOT which assures the installation of these improvements within two years of the recording of East Renton: In this event. Intersection improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the recording of East Renton. or a financial guarantee has been posted by others which assures the installation of these improvements. then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements. in an amount proportional to the impacts of East Renton. The pro"rata share dollar amount to be paid shall be set by WSDOT. and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot courit • The trip distribution for East Renton • The total trips contributed to the intersection of SR 900.14S th Ave by the plats of Aster Park (LOOP0024). Stone Ridge 9L99P3008). East Renton (L02P0005). Shamrock (L02P0014). Rosemonte (aka Ironwood -L03P0018). Martin (L05P0019) and any future land use applications submitted to King County for which compliance with the King County Intersection Standards (KCC 14.80) is required at either the SR 900/148'" Ave intersection. or the SR 900/164 1h Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "Iatecomer's" system prior to final plat recording. that system may be followed in lieu of the approach described above. at the discretion of the applicant. as long as at a L02POOOS / REVISED SEPA TO December 29, 2006 Page 4 minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years of the date of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21A.28.060A] 2. Documentation shall be provided to demonstrate to the satisfaction of WSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900/148'h . Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 148'" Ave., to maximize the entering sight distance for the north and south legs of . the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 21A.28.060A] . Extended Period for Comments and Appeats The SEPA determination may be appealed in writing to the King County Hearing Examiner. Written c6mments or a notice of appeal must be filed with the Department of Development and Environmental Services (DOES) at the address listed below prior to 4:30 p.m. on January 22, 2007 be accompanied with a filing fee of $250.00 payable to the King County Office of Finance .. Please reference the file numbers when corresponding. If a SEPA Appeal is filed, the appellant must also file a Statement of Appeal with DOES at the address listed below prior to 4:30 p.m, on January 22, 2007. The Statement of Appeal shall identify the decision appealed (including the file number) and the alleged errors in that SEPA decision. The Statement of Appeal shall state: 1) specific reasons why the decision should be reversed or modified; and 2) the harm suffered or anticipated by the appellant, and the relief sought. The scope of an appeal shall be based on matters or issues raised in ttie Statement of Appeal. Failure 10 timely file a Notice of Appeal, appeal fee or Statement of-Appeal, deprives the Hearing Examiner of jurisdiction to consider the appeal. CommenUappeal deadline: Appeal filing fee: Address for commanUappaal: Res ible Official: 4:30 PM on January. 22,2007 $250 check or money order made out to the King County Office of Finance King County Land Use Services Division 900 Oakesdale Avenue SW Renton, WA 98057-5212 ATTN: Current Planning Section December 29, 2006 Date Signed , Road Services Division Department of Transportation KSC-TR-0231 201 South Jackson Street Seattle, WA 98104-3856 March 31, 2008 Sheri Murata l21l2-llSthAvenueNE Kirkland, W A 98034 o RE: Road Variance L07VOl16 -East RentonIRosemonte -Related Files L02POO/S and L03P0018 Dear Ms. Murata: Thank you for your application for a variance from the 1993 King County Road Standards (KCRS). You requested a variance from Section 2.02 concerning the design of the shoulder on the east side of I 48th Avenue SE. The street at I 48th Avenue SE is a collector arterial that the Department of Development and Environmental Services is requiring ,an eight-foot shoulder on the east side of the road. You propose a thickened edge within the shoulder, with the ditch section eliminated and replaced with pipes and catch basins. The proposed thickened edge section is on the opposite side of the road from the urban plat frontage. Since the applicant is lowering the entire road for 623 linear feet to improve the sight distance'along and beyond the plat frontage, the east side of the road must be reconstructed. The KCRS only allows thickened edge roadways on neighborhood collectors 'and local access streets. A thickened edge would not be an appropriate design on an arterial or as proposed within the shoulder section. Shoulders on arterials should allow for cars to pull off the road and provide a "recovery area" adjacent to the traveled way. A thickened edge design is not compatible for vehicular pullover maneuvering. The proposed shoulder does not provide for safe pedestrian use. Per the Public Rule on Procedures for Requesting Variances form the KCRS (pUT 10-2), a variance must produce a compensating or comparable result that is in the public interest. In addition, the variance must produce a result that is safe and functional. Your proposal for a thickened edge fails this test._ I respectfully deny the variance request. This decision applies only to KCRS identified in the variance request. All design requirements in the KCRS and other regulations, such as surface water management and zoning, must be satisfied for a land use permit application. The applicant retains the rights and privileges afforded by King County Code and adopted Public Rules pertaining to road variance processing (KCC 14.42, PUT 10-2). Per Section 6.7 of the Public Rule, variance appeals must be made to the Director of the Department of Transportation within thirty days of this variance decision. ,D:).._._. , Sheri Murata March 31, 2008 Page 2 A copy of staff's analysis, findings, and conclusions is enclosed. If you have any questions, please call Craig Comfort, Road Variance Engineer, Traffic Engineering Section, at 206-263-6109. Sincerely, ~AJ~o~ Paulette Norman, P.E. County Road Engineer PN:CC:kc Enclosure cc: James Sanders, P.E., Development Engineer, Land Use Services Division (LUSD), Department of Development and Environmental Services (DDES) Pete Dye, P.E., Senior Engineer, LUSD, DDES Linda Dougherty, Division Director, Road Services Division (RSD), Department of Transportation (DOT) Matthew Nolan, P.E., County Traffic Engineer, Traffic Engineering Section, RSD, DOT Fatin Kara, P .E., Supervising Engineer, Traffic Engineering Section, RSD, DOT Kris Langley, Senior Engineer, Traffic Engineering Section, RSD, DOT Craig Comfort, P.E., Road Variance Engineer, Traffic Engineering Section, RSD, DOT ,. W King County King County Road Services Division Department of Transportation Traffic Engineering Section KSC-TR-0222 201 South Jackson Street Seattle, WA 98104-3856 March 31, 2008 TO: Variance File FM: Craig Comfort, P.E., Road Variance Engineer, Traffic Engineering Section ----.. -_ .. _--- RE: Road V ariance I:;07VO 116 East Renton-(AKARosemonte) ""-Related File L02P0005 Applicant's Presentation: 1. A variance is requested for an alternative shoulder design along the east side of 148th Avenue SE, an urban collector arterial. This road is being lowered to enhance sightlines per the plat conditions and per variance L03V0049 for the East Renton Plat. The plat will be providing urban frontage improvements on the west side of the road and is required by the Department of Development and Environmental Services (DDES) to provide an eight-foot shoulder on the east side of the road with the road reconstruction. The applicant proposes a thickened edge section with piped drainage. 2. The applicant will be lowering 623 lineal feet of road to improve the sight distance and this is compensatory to King County. 3. The thickened edge section is proposed because there is an upward sloping bank on the east side of 148th Avenue SE, and a standard design with an eight-foot shoulder and ditch, which would result in grading extending beyond the right-of-way unless a rockery or retaining wall were constructed. The proposed modified section provides 17 feet to 21 feet of pavement east of the centerline which exceeds the existing 12.5 to 18.5 feet of paving. 4. There is no nexus for requiring additional levels of improvement beyond what is practical and that would otherwise restore the roadway to existing conditions. Staffs Findings and Conclusions: 1. Reconstructing a substandard shoulder on the east edge of 148th Avenue SE would open King County up to additional liability. The proposed thickened edge section within the shoulder does not facilitate vehicles pulling off the road or utilizing the shoulder as a recovery area. ,.. , Variance File March 31, 2008 Page 2 2. The King County Road Standards (KCRS) requires that an eight-foot shoulder be placed along rural collector arterial. Footnote 8 in Section 2.02 allows an alternative of vertical curb and sidewalk. Turnpike sections are allowed on neighborhood collectors but not arterials. 3. The variance request submittal makes no arguments on safety, functionality. maintainability or that the proposal is comparable to the KCRS. The applicant's proposal appears to be essentially related to cost considerations. SITE ENGINEERING & PLANNING STRUCTURAL REVIEW TRANSMITTAL TO: Hou-Ching Chow, Plan Review Services *FM: Ted Cooper, Review Engineer ~ *RE: East Renton & Rosemonte Plats (L02P0005, L03P0018) * Activity/Charge #L07SR054 (Project) * DATE: September 29,2008 Please accept and review the attached Structural Review Package. The Engineering Review Section has beguri reviewing the engineering plans for the road and storm system; we anticipate completion in October 2008. Your efforts in assisting us with this deadline are greatly appreciated. Please contact me at (206) 296-7163 when your review begins or at any time you require additional information. Upon structural approval, please return the plans and approval documentation to the Site Engineering and Planning Section with an approval memo stating any required fees. *Description of Structures: 1) Structural block walls built on geogrid reinforced fills on Tract K and Lots 9,76,77 78 and 67. 2) Rockeries on or adjacent to Lots 19 through 23, 28 and 53 through 59. 3) Reinforced concrete retaining wall: 285'-long, supports fills, up to 12'-high, in pond tract. IMPORTANT NOTES: THE STRUCTURAL BLOCK WALL CALCULATION SHEETS ALL HAVE NOTES STATING, "THESE CALCULATIONS ARE FOR PRELIMINARY DESIGN ONLY AND SHOULD NOT BE USED FOR CONSTRUCTION WITHOUT REVIEW BY A QUALIFIED ENGINEER" *Locations of Structures (Page # and/or describe location): I On civil plans see the "GEOTECHNICAL PLANS" sheets & sheet 18 for structural design details. Public ROW: Public Tracts: Private Tracts: Easement (Joint-Use Driveway) (Type) Existing ______ _ Existing ______ _ Existing ______ _ Existing ______ _ RestrictionslRequirements Related to the Structure: (None) (e.g. other approvals (HPA, DOT), ordinances, elevations) * Submittal Package Includes: Engineering Plans (Road/Drainage) Structural Drawings and Plans Manufacturing Specifications (if necessary) Design Calculations Soils Report List of Key Contacts: 1 3 NA ---3 In TIR Future Future----=X-:------ Future X ___ _ Future ______ _ King County Sensitive Area Staff: _.,..-:.N.!.!i""ck"-"'G"'iI",le"-!n _______ _ Design Engineer: Structural: Kurt D. Merriman Engineering Plans: Sheri Hideko Murata Other: ____________________________ _ Installationllnspection Inspection Responsibility of Commercials: ________________ _ Contractor License # (if needed) ____ _ Structural Value $ ....:? ___ _ Attachments ____________________________ _ REVISION DATE: _____________ _ SIGNATURE: ______________ _ *REQUIRED s:lbsdlsite _ englformslhou chow's structual.doc 10/23/02 ~r-!!=~ITESTRUCTURES I A Division of Kosnik Engineering, PC EAST RENTON / ROSEMONTE Site Retaining Wall King County, Washington Structural Calculations for Permit Submittal Project No. S-08-040 April 25, 2008 1051119TH Ave SE, Suite C, Everett,WA 98208. (425) 357·9600 (phone). (425) 357·9622 (fax) i I ' East Renton / Rosemonte Site Retaining Wall Project No. S-08-040 STRUCTURAL CALCULATIONS INDEX Design Criteria 12' Retaining Wall Design 9' Retaining Wall Design AppcndixA: Retaining Wall Section Excerpts from Geotechnical Report 01 02-05 06-09 Al A2-A4 DESIGN CRITERIA Code: Permitting Agency: Foundation Design: East Renton / Rosemonte Site Retaining Wall 2006 IBC King County Foundation design is based on the following values derived from the geotechnical report by Associated Earth Sciences, Inc. dated November 12, 2007: Allowable Bearing Pressure: 3,000 psf Lateral Earth Pressures on Vault Walls: Active Condition: 35 pcfEFW Seismic Addition: E = 4H psfUniform Passive Soil Resistance: Coefficient of Base Friction: Saturated Soil Density: 250 pcfEFW (F.S. = 1.5) 0.35 (F.S. = 1.5) 125 pcf Vertical Loads Adjacent to Wall: 2' Sloping Soil Surcharge: Live Load Surcharge: Material Requirements: 250 psfUniform 150 psfUniform Rebar: Concrete: Grade 60 fc= 3000 psi SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date '1·:;z.5·""i\' prj. no. S-08-040 12' RETAINING WALL REINFORCING Active Pressure + Soil Surcharge + LL Depth to rebar center Comp block depth EFWa(pcf) Surcharge(psf) Soil Density(pcf) LF active LF surcharge 7.56 2.36 1.6 1.6 H from to~ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 H from top n;~K~~~ Ms 62 271 662 1269 2129 3276 4745 6571 8789 11433 14540 18144 22280 26983 32288 Ms 18144 7852 Mu As 99 0.003 433 0.014 1058 0.033 2031 0.064 3407 0.107 5242 0.165 7592 0.239 10513 0.331 14062 0.442 18293 0.576 23264 0.732 29030 0.913. 35648 J.J22 43172 1.358 51660 1.625 Mu As 29030 1.011 12563 0.437 Vertical Reinforcing: bar size: spacing: # .6 ·:-··-~-·if It ole As= ... 0.44 sq in ~ Footing to Wan Dowels: bar size: # 7 spacing: ifr';~ " olc As ="',:1,20 sq in <! 1.01 .<<':.; tension controlled cracking: p " pt: P = 0.0100 pt = 0.0136 development length: 47.9 " in 3000psi conc Extend Dowels: 6.8 fi minimum into wall -+ go to "li.l;i\t;:,,,,''!fi''./ end hook development: 13,4 "in 3000psi conc Embed Dowels: 11.3 in min into footing -+ go to' 13 in into 16 in fig ./ / Horizontal Reinforcing: bar size: # 5 ;/' spacing: 12 II ole each face: no ,."1; p= 0.0026 " 0.0020./ SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date Ii -2-~ -ot, prJ. no. S-08-040 12' RET AINING WALL REINFORCING Active + Soil Surcharge + Seismic Seismic Pressure Component Unifonn Lateral Earth Pressure '11' H psf - Load Factor for Seismic Pressure Component H from top Wall thick' .' to in Concrete cover .. '.:' i2: in Rebar size, ? Concrete Strength fc .. 30Q,(i psi Depth to rebar center Comp block depth EFWa(pcf) , Surcharge(psf) Soil Density(pcf) ... 7.56 2.36 ... '·35 , '250 125 I 2 3 4 5 6 7 8 9 10 11 12 \3 14 15 .... 48 psf ··.1.00 Ms Mu As 65 89 0.003 283 395 0.012 689 972 0.031 1317 1877 0.059 2204 3167 0.100 3384 4896 0.154 4892 7121 0.224 6763 9899 0.311 9032 13284 0.418 11733 17333 0.545 14903 22103 0.695 18576 27648 0.870 22787 34025 1.071 27571 41291 1.299 32963 49500 1.558 LF active :', . 106 ,n. Ms Mu As 18576 27648 0.962 H from top __ -:-=~,----,,-::=;~_-=~:;. .. ··12 ..•. , '. "'8.6 LF surcharge ,. Vertical Reinforcing: bar size: spacing: Footing to Wall Dowels: #6 . '.12 "o/c bar size: # 7 8074 11853 0.413 As= 0.44 sq in " spacing: 6 " ole As = 1.20 sq in " 0.96 1-" tension controlled cracking: p S pt: p = 0.0100 pt= 0.0\36 development length: 47,9 " in 3000psi cone Extend Dowels: 6.6 fi minimum into wall ..... go to 7 fi "'; end hook development: 13.4 " in 3000psi cone Embed Dowels: 10.7 in min into footing ..... go to . :'13 in into 16 in fig v" : Horizontal Reinforcing: bar size: #.5 spacing: . c{~ II ole each face: no p= 0,0026 " 0.0020//' SITE STRUCTURES Project East RentonIRosemont sheet _'i...L __ _ 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 date 11-2.->" -"" 't prj. no. S-08-040 12' RETAINING WALL REINFORCING Active Pressure + Surcharge Ha(ft)= 13.33 "., Hp(FT)=1.50 CoeFrict= :P;53 " W(surchg)= 2000 WI(heel)= 7500 W2(wall)= 1500 W3(toe)= 42 W4(ftg)= 1566 Wtotal= 12608 EFWa(pcf)= 35 ,.," ,-, EFWp(pcf)=250 ' FSpassive= tf.oo Dsoil(pcf)= 125.00 , Surcbg(psf)= '4&0.00 Fsrchg(lbs)= 1493 Fa(lbs)= 3111 Fp(lbs)= 281 Ffrict(lbs)= 6682 Tw(in)= 10 Hw(ft)= 12, D(wall)pcf= 150 " Allowalbe Bearing Press~re LF oveturn= 105 ,',. , Ms-ot(ft-lb)= 23642 Mu-ot(ft-lb)= 35463 Tftg(in)=,j 6.00 :'~.tr;"'· . Wftg(ft)=!7i~3 ",~,,,,,,,,, Lheel(ft)= i§;Q.0 Ltoe(ft)= 2;00 D(ftg)pcf= 'i~o FS sliding= 1.51 /, FS slide reqd= l.50 ./. Net Sliding= -2359 Xcw(ft)= 3.04 Ecc-s(ft)= 1.88 Ecc-u(ft)= 2.81 Xresult-s(ft)= 4.91 Xresult-u(ft)= 5.85 Tr-s(ft)= 2.92 Tr-u(ft)= 1.98 3rd point= 2.61 CASE= Service y::----' RESULTANT WITHIN MiDDLE 3rd) Tr (ft)= 2.92 Lbrg(ft)= 7.83 '--.---:-/ QI(psf)= 2841// S3000psf ( Q2(psf)= 380 CASE= Ultimate RESULTANT OUTSIDE MIDDLE 3rd Tr (ft)= 1.98 Lbrg(ft)-5.94 Q I (psf)= 4245 S 1.5 x 3000 = 4500 psf / Q2(psf)= 0 HEEL REINFORCING DESIGN Top bar cover (in)= Top bar size = Top bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sq in)= '2'" dllir 13.56 J.J8 12.97 0.60 ./ TOE REINFORCING DESIGN Bot bar cover (in)= Bot bar size = Bot bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sq in)= W(surchg) + W(heel) + W(heel DL) (Ibs)= 10500 Subgrade Reaction (Ibs)= 5827 Load Factor = j.5 " .. Mu= As reqd = As min = 1.33 x As reqd = Toe Reaction (lbs)= W(toe) + W(toe DL) (lbs)= Load Factor= 1.5 Mu= As reqd = As min = 1.33 x As reqd = 29663 ft-lbs @ wall 0.51 sqinperft 0.54 sq in per ft .f' 0.68 sq in per ft 7051 441 13638 ft-lbs @ wall 0.25 sq in per ft 0.51 sq in per ft 0.33 sq in per ft Y / SITE STRUCTURES Proj ect East RentonIRosemont sheet " -~-- 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 12' RETAINING WALL REINFORCING Ha(ft)= 13)~3 .,. Hp(FT)= r.So . W(surchg)= 1250 Wl(heel)= 7500 W2(wall)= 1500 W3(toe)= 42 W4(ftg)= 1566 Wtotal= 11858 EFWa(pct)= }5' EFWp(pct)=25.0 FSpassive=l ;00 Dsoil(pct)= #5.00 Wseismic(pst)= AS.OO Fsrcbg(lbs)= 933 F seismic= 640 Fa(lbs)= 3111 Fp(lbs)= 281 Ffrict(lbs)= 6285 FS sliding: 1:49 v:. FS slide reqd= i,41 /' . Net Sliding: -1881 Xcw(ft)= 2.81 Ecc-s(ft)= 1.65 Ecc-u(ft)= 2.07 date '1 . .l-<? .~ prJ. no. S-08-040 Active + Soil Surcharge + Seismic Tw(in)=lO Hw(ft)= 'li D(wall)pcf= Bo Surchg(pst)= 250.00' Tftg(in)=16.,00. Wftg(ft)= 7.83 .' ," . Lbeel(ft)=5.00. ' .. . Ltoe(ft)= 2.00 D(ftg)pcf= 150 Allowalbe Bearing Pressure "< '>:, 3000 psf LF oveturn=1.25 Ms-ot(ft-Ib)= 19620 Mu-ot(ft-Ib)= 24525 D key(ft)= .9,00 Xresult-s(ft)= 4,46 Xresult-u(ft)= 4,88 Tr-s(ft)= 3.37 Tr-u(ft)= 2.95 3rd point= 2.61 -.," ~- CASE= Service RESULTANT WITHIN MIDDLE 3rd Tr (ft)= 3.37 Lbrg(ft)= 7.83 QI(pst)= 2149 / :s 3000 psf ~ Q2(pst)= 879 /' CASE= Ultimate RESULTANT WITHIN MIDDLE 3rd Tr (ft)= 2.95 HEEL REINFORCING DESIGN Top bar cover (in)= '2'·' Top bar size = /7" Top bar spacing (in)= 0p' Deptb to Reinf d (in)= 13.56 Comp Block a (in)= Ll8 d -aJ2 (in)= 12.97 As provided (sq in)= 0,60/' TOE REINFORCING DESIGN Lbrg(ft)= 7.83 QI(pst)= 2629 :s 1.5 x 3000 = 4500 psf v Q2(pst)= 399 W(surcbg) + W(heel) + W(beel DL) (lbs)= 9750 Subgrade Reaction (lbs)= 6425 Load Factor = t25 . Mu= As reqd = As min = 1.33 x As reqd = Toe Reaction (lbs)= W(toe) + W(toe DL) (lbs),,,, Load Factor: 1.25 Mu= As reqd = As min = 1.33 x As reqd = 19761 ft-Ibs @ wall 0.34 sq in per ft 0.54 sq in per ft 0045 sq in per ft ./ 4283 441 6687 ft-Ibs @ wall 0,12 sq in per ft 0.51 sq in per ft 0.16 sq in per ft ,/ I- i SITE STRUCTURES Project East RentonIRosemont sheet date 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 9' RET AINING WALL REINFORCING H from top Wall thick Concrete cover Rebar size Concrete Strength fc Depth to rebar center Comp block depth ::~ in "" ,)? 3000 psi 7.63 0.87 LF active ':? ,'·:1.6 LF surcharge.'" _ ... -'-']'.6 Vertical Reinforcing: bar size: spacing: Footing to Wall Dowels: I. ~_ bar size: L# 6,\ spacing: " '1112 " O/C tension controllea'cni~king: p $ pt: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 J-f ./-<; . "' .. prj. no. S-08-040 Active Pressure + Soil Surcharge + LL Ms 62 271 662 1269 2129 3276 4745 6571 8789 11433 14540 18144 22280 26983 32288 As= Mu 99 433 1058 2031 3407 5242 7592 10513 14062 18293 23264 29030 35648 43172 51660 As 0.003 0.014 0.033 0.063 0.106 0.163 0.237 0.328 0.439 0.571 0.726 0.905 1.112 1.347 1.611 / 0.31 sq in 2:0.31 '"' • As =ji:44 sq in 2: 0.43./' p= 0.0037 pt= 0.0136 development length: 32.9 " in 3000psi cone ':""-'~-'-"'-'-"-'i"'~' Extend Dowels: 3.9 ft minimum into wall--> go to "'.' '.;;:;""":~ ft ,/ end hook development: 11.5 " in 3000psi cone Embed Dowels: 11.3 in min into footing --> go to' ,i." "·i~. in into Horizontal Reinforcing: bar size: spacing: 12 " ole each face: no p= 0.0026 ~ 0.0020/ 16 in ftg ",' ,----------------------------------------------------~~ SITE STRUCTURES 1051119th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont . " ~ .< sheet 7 --'---date '1' __ ~ -P?: prj. no. S-08-040 9' RETAINING WALL REINFORCING Active + Soil Surcharge + Seismic Seismic Pressure Component Uniform Lateral Earth Pressure 4 H psf- Load Factor for Seismic Pressure Component Wall thick Concrete cover Rebar size Concrete Strength fc Depth to rebar center Comp block depth EFWa(pcf) . Surcharge(psf) Soil Density(pcf) .-. .--·:::\io in ---\\2 in <Nit psi 7.63 0.87 35 250 ,125 LF active dO. ••• LF surcharge .. ·,1:6 1.6 Vertical Reinforcing: bar size: # 5 H from top 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 H from top ···:· .• 9 ·7,8 ... 36 psf ·.";00 Ms Mu As 59 83 0.003 259 371 0.012 635 918 0.029 1221 1781 0.056 2054 3017 0.094 3168 4680 0.146 4598 6827 0.213 6379 9515 0.297 8546 12798 0.399 11133 16733 0.522 14177 21377 0.667 17712 26784 0.835 21773 33011 1.030 26395 40115 1.251 31613 48150 1.502 Ms Mu As 8546 12798 0.395 5993 8931 0.276 spacing: . 12 II ole 0.31 sq in ~ 0.28.// Footing to.Wall Dowels: bar size: # 6 spacing: :12 " ole As ~ 0.44 sq in ~ OAO .//' tension controlled cracking: p S pI: P ~ 0.0037 pt~ 0.0136 development length: 32.9 " in 3000psi conc Extend Dowels: 3.7 ft minimum into wall .... go to .. :~ ft .,;; end hook development: 11.5 "in 3000psi conc Embed Dowels: 10.3 in min into footing .... go to ''13 in into 16 in ftg ,/ Horizontal Reinforcing: bar size: spacing: "J2 II ole each face: -no --~----p~ 0.0026 " 0.0020/ SITE STRUCTURES 1051119th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date '-/-tS ""? prj. no. S-08-040 9' RETAINING WALLREINFORpNG Active Pressure + Surcharge Ha(ft)~ ]033' Hp(FT)~ Iso CoeFrict= i()j3 .' W(surchg)~ 1532 WI (heel)~ 4309 W2(wall)~ 1125 W3(toe)~ 28 W4(ftg)~ 1200 Wtotal= 8194 EFWa(pcf)=·3S: EFWp(pcf)~ :~.~Q;.~:!::·.:X' FSpassive~ iooj'·';,c;,. """'~:':":"~:~"" 'i', :'! !:'(~:,::,," Dsoil(pcf)~J~5;9.o. . Surchg(psf)~ Abo.ob, . Fsrchg(lbs)~ 1157 Fa(lbs)~ 1869 Fp(lbs)~ 281 Ffrict(lbs)~ 4343 Tw(in)~,!O Hw(ft)~9 D(waU)pcf= 150 . Allowalbe Bearing Pressure LF oveturn~ 1.5 Ms-ot(ft-Ib)~ 12275 Mu-ot(ft-Ib)~ 18413 FS sliding~ i.53/0s slide reqd~1;50 '/ Net Sliding~ -1598 D key(ft)~(j:OO " '. Xcw(ft)~ 2.41 CASE~ Service Ecc-s(ft)~ 1.50 Ecc-u(ft)~ 2.25 Xresult-s(ft)~ 3.90 Xresult-u(ft)~ 4,65 RESULTANT WITHiN MIDDLE 3rd Lbrg(ft)-6.00 Ql(psf)~ 2600 /' S 3000 psf ./ Q2(psf)~ 131 / Tftg(in)~ 16,90 . Wftg(ft)~6.00 Lheel(ft)~ 3.83. Ltoe(ft)~ 1.34 D(ftg)pcf=150 3000 psf Tr-s(ft)~ 2.10 Tr-u(ft)~ 1.35 3rd point= 2.00 Tr (ft)~ 2.1 0 CASE= Ultimate RESULTANT OUTSIDE MIDDLE 3rd Tr (ft)~ 1.35 HEEL REINFORCING DESIGN Top bar cover (in)~ 2 .. Top bar size ~ /6"'-:::: .. Top bar spacing (inr \E /-' Depth to Reinf d (in)~ 13.63 Comp Block a (in)~ 0.87 d-aJ2(in)~ 13.19 As provided (sq in)~ 0.44 ./ TOE REINFORCING DESIGN Bot bar cover (in)~ . .3'<"<':,. Bot bar size == /:I~::~'~:--_-;:':::,;-:"··':·: Bot bar spacing (in)~ '-i1.ii ,' :·F>' '. Depth to Reinf d (in)~ 12.69 Comp Block a (in)~ 0,60 d -a/2 (in)~ 12,39 As provided (sq in)~ 0,31 / Lbrg(ft)-4.04 QI(psf)~ 4055 S 1.5 x 3000~4500psf./ Q2(psf)~ 0 W(surchg) + W(heel) + W(heel DL) (lbs)~ 6607 Subgrade Reaction (lbsr 3521 Load Factor ~1;5 Mu~ As reqd ~ As min = 1.33 x As reqd = Toe Reaction (lbs)~ Wetoe) + Wetoe DL) (lbs)~ Load FactoF 1.5" Mu~ Asreqd~ As min ~ 1.33 x As reqd ~ 14483 ft-Ibs @wall 0.24 sq in per ft 0.55 sq in per ft / 0,33 sq in per ft,/ 4524 295 5849 ft-Ibs @ wall 0.10 sq in per ft 0.51 sq in per ft ! O,14sqinperft./ . ,------------------------------ SITE STRUCTURES Project East RentonIRosemont sheet "'I ---l __ _ 10511 19th Ave SE. Suite C Everett. WA. (425)-357-9600 9' RETAINING WALL REINFORCING Ha(ft)~ 10.33 Hp(FT)~ J .50 CoeFrict= 0.53 W(surchg)~ 957.5 WI(heel)~ 4309 W2(walI)~ 1125 W3(toe)~ 28 W4(ftg)~ 1200 Wtotal~ 7619 EFWa(pcf)= :J~ ., . EFWp(pcf)= i~o . FSpassivFLo6 " Dsoi1(pcf)= 12? .09 . Wseismic(psf)~ 36.00 Fsrchg(lbs)~ 723 F seismic~ 372 Fa(lbs)~ 1869 Fp(lbs)~ 281 Ffrict(lbs)~ 4038 date '1' 2-. -<>$ Pl]. no. S-08-040 Active + Soil Surcharge + Seismic Tw(in)~lO.. . Tftg(in)~ 16.00 Hw(ft)~ l",' Wftg(ft)~6:06, D(waU)pcf= .150 .' .. ,Lheel(ft)~ ;{Sl· Surchg(psf)~2~O.OO' . Ltoe(ftr .1 . .34, D(ftg)pcf=.iSQ .' AIlowalbe Bearing Pressure LF oveturn= j,,2f . Ms-ot(ft-lb)~ 9509 Mu-ot(ft-Ib)~ 11887 ',3000. psf -_. / FS sliding~·~.46 /( FS slide reqd~l.42 _A··.· D key(ft)~i>.OO· Net Sliding~ -1355 Xcw(ft)~ 2.20 Ecc-s(ft)~ 1.25 Ecc-u(ft)~ 1.56 Xresu1t-s(ft)~ 3.45 Xresu1t-u(ft)~ 3.76 Tr-s(ft)~ 2.55 Tr-u(ft)~ 2.24 3rd point= 2.00 CASE~ Service CASE~ Ultimate RESULT ANT WITHIN MIDDLE 3rd Lbrg(ftF 6.00 QI(psf)~ 1841./ S 3000 psf .# Q2(psf)= 698' / Tr (ft)~ 2.55 RESULTANT WITHIN MIDDLE 3rd Tr (ft)~ 2.24 Lbrg(ftF 6.00 QI(psf)~ 2238 S 1.5 x3000 ~ 4500 psf /. Q2(psf)~ 302 HEEL REINFORCING DESIGN Top bar cover (in)~ Y'o;' •... :-- Top bar size ~ (6 ..... ' ., Top bar spacing (in)~i2l·· Depth to Reinfd (in)~ -'13,63 Camp Block a (in)~ 0.87 d -al2 (in)= 13.19 As provided (sq in)= 0.44 .; TOE REINFORCING DESIGN Bot bar cover (inF Bot bar size = Bot bar spacing (in)~ Depth to Reinf d (in)= Camp Block a (in)= d -al2 (in)~ As provided (sq in)= 3 (5-~\ I 17 ; 1...-. 12.69 0,60 12.39 0.31 / W(surchg) + W(heel) + W(heel DL) (lbs)~ 6032 Sub grade Reaction (lbsr 4072 Load Factor ~L25 Mu= As reqd= As min = 1.33 x As reqd ~ Toe Reaction (lbs)~ W(toe) + W(toe DL) (lbs)~ Load FactoF 1.25 Mu= As reqd ~ As min = 1.33 x As reqd ~ 9241 ft-1bs @ wall 0.16 sqinperft 0.55 sq in per ft 0.21 sqinperft « 2501 295 2588 ft-Ibs @ wall 0.05 sq in per ft 0.51 sq in per ft 0.06 sq in per ft., rs' SITE STRUCTURES I A DlvlJlon o' I>olnlt tnglnurlng, ~C -, _ .... '. A qMBlon of ~nlk engineering Pq' . I .e~A~ST!....!!!R .-w.TO~N~/R~O~SE:!M~O:!!NT.!-,+....:S:...:H....:E=E_T....:: --1 ·'1D51f191H AVE BE, SUITE C 'DA11I EVERETT. WASHINGTON II8ZJ8 '1 • 1-~ • &>'Pf A 1 PH: (425)-S67-seco FAX: (4l!S)-S67-8B22 .... .., S-08-040 L Tw L -'1<--__ --+--_1 1 Daoil: DENSITY OF THE SOIL !PCF) Dftg: DENSITY OF THE FOOTING !PCF) Dwell: DENSITY OF THE WALL !PCF) RETAINING WALL SECTION SCALE N/A RosemOlllaEast Renton Property King County, Washington Subsuiface Exploration, Geologic Hazard, and Geotechnical Bllg/n •• ring Repon Design RecommendatiolJs After the bearing stratum has been reached, the trench should be immediately backfilled, We recommend the use of quarry spalls or 2-to 4-inch size crushed rock for backfill. The crushed rock must be tamped into place to achieve a tightly packed mass; this may be done with either a "Hoepac" type compactor mounted on the excavator or more Iypically, with the bucket of the excavator itself, Staging areas should be maintained so that that rock is not contaminated by mud prior to placement in the trench. Equipment access to trench locations should also be maintained , Spread footings may then be used for building support when placed over properly constructed rock trenches that bear on medium dense to dense, natural soils. Footings which bear on approved rock trenches may be designed for an allowable bearing pressure of 3,000 pounds per square foot (pst) including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. However, all rock trenches must penetrate to the prescribed bearing stratum and no trenches should he founded in or ahove loose, organic, or existing fill soils. In addition, all footings must centered over the trenches and have a minimum of 14 inches for one-story structures, 16 inches for two-story structures, and 18 inches for three-story structures. Anticipated settlement of footings founded on approved rock trenches should be on the order of 1 inch. However, disturbed material not removed from footing trenches prior to footing placement could result in increased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the rock trenches are undisturhed and construction conforms with the recommendations contained in this report. Such inspections may be required by the governing municipality. Perimeter footing drains should be provided as discussed under the section on "Drainage Considerations." 11. 2 Shallow Foundations In areas where existing fill is thin or absent, or where existing fill is removed and new structural fill pads are properly constructed, shallow spread footings may be utilized for building support when founded either directly on the medium dense to very dense, natural glacial sediments, or on structural fill placed over these materials. Natural sediments suitable for foundation support were generally encountered in our explorations at depths of approximately 0.5 to 2 feet, except in those areas described above where existing fill occurred. For footings founded either directly upon the medium dense to dense, natural sediments or on structural fill placed over these materials, ~commend that an allowable foundation soil rearing pressure of 3,000 psf be utilized for design pmpos e s, including both dead and live loads. An increase of one-third may be used for short -term wind or seismic loading. Perimeter footings for the proposed buildings should be buried a minimum of 18 inches into the surrounding soil for frost protection. Interior footings should be buried a minimum of 12 inches. All footings must penetrate to the prescribed stratum and no footings should be November 12, 2007 ASSOCIATED EARTH SCIENCES, INC. SGMs _ KE()4766lJl a ProjcClsll00407661KElWP Page 25 ® '1'J..<>.~ -I I I ! I ! I , ! I I I , , i ! I I ~ I I I I ! RosemonJ-Easz Renton Property Kine County, Washington Subsurface Exploration, Geologic Hazard, and Geotecllnical Engineering Repon Design RecommendariollJ founded in or above loose or organic soils. All footings should have a minimum width of 14 inches for one-story structures, 16 inches for two-story structures, or 18 inches for three-story structures . It should be noted that the area bounded by lines extending downward at IH:IV from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D 1557. In addition, a 1.5H:IV line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edge of steps or cuts in the bearing soils. Anticipated settlement of footings founded as .described above should be on the order of l4 inch. However, disturbed soil not removed from footing excavations prior to footing placement could resnlt in increased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the design bearing capacity of the soils has been attained and that construction conforms to the recommendations contained in this report. Such inspections may be required by King County. Perimeter footing drains should be provided as discussed under the section on "Drainage Considerations." 12.0 LATERAL WALL PRESSURES All backfill behind walls or around foundation units should be' placed as per our recommendations for structural fill and as described in this section of the report. Horizontally backfilled Vialls that are free to yield laterally at least 0.1 percent,of theirl!eighLmay. be designed using an equivalent fluid equal to 35 pcf. Fully restrained, horizontally backfilled rigid walls that cannot yield should be designed for an equivalent fluid of 50 pcf. If roadwayS, parking areas, or other areas subject to vehicular traffic are adjacent to walls, a surcharge equivalent to 2 feet of soil should be added to the wall height in determining lateral design forces. Walls that retain sloping backfill at a maximum angle of 2H:IV should be designed using an equivalent fluid Rre~!ure of 55 rcf for. yielding conditions or' 75 pcf for fully restrainea condiiiOns.-~ . _. --.--.. -. ---.. As required by the 2006 !BC, retaining wall design should include a seismic surcharge pressure in addition to the equivalent fluid pressures presented above. Considering the site soils and the recommended wall .backfill materials, we recommend a seismic surcharge pressure of 4H and 8H psf where H is the wall height in feet, for the "active" and "at-rest" loading conditions, respectfully. The seismic surcharge should be modeled as a rectangular distribution with the resultant applied at the mid-point of the wall. November 12, 2007 ASSOCIATED EARTH SCIENCES, INC. SGBln -KE04766BI -PrtIjeClsUoo«)766IKEIWP Page 26 I I i I ! I ! I , 1 i Rosemonl-Eost Remon Property King Coun!}'. Washington Subsuiface Exploration, Geologic Hazard, and Geotechnical Englneerillg R.pon Design Recommendations The lateral pressures presented above are based on the conditions of a uniform horizontal backfill consisting of the on-site, natural glacial sediments, or imported sand and gravel compacted to 90 percent of ASTM:D 1557. A higher degree of compaction is not recommended as this will increase the pressure acting on the wall. It is imperative that proper drainage be provided so that hydrostatic pressures do not c!evelop against the walls. This would involve installation of a minimum I-foot-wide blanket drain to within I foot of finish grade for the full wall height using imported washed gravel against the walls. A prefabricated drainage mat is not an acceptable substitute for the gravel blanket drain. 12.1 Passive Resistance and Friction Factors Lateral loads can be resisted by friction between the foundation and the natural glacial soils or supporting structural fill soils, or by passive earth pressure acting on the buried portions of the foundations. The foundations must be backfilled with structural fill and compacted to at least 95 percent of the maximum dry density to achieve the passive resistance provided below. We recommend the following design parameters: • Passive equivalent fluid -250 pcf • Coefficient of friction 0.35 The above values are allowable and iQe a safely factor of atleasW! 13.0 FLOOR SUPPORT Concrete, slab-on-grade floors may be used for the new buildings where the slabs are underlain by dense, natural soils or structural fill. We recommend crawi spaces and structural floors be used where foundations are supported on piles or rock trenches. If crawl space floors are used, an impervious moisture barrier should be provided above the soil surface within the crawl space. Slab-an-grade floors should be cast atop a minimum of 4 inches of pea gravel or washed crushed rock to act as a capillary break. The floors should also be protected from dampness by covering the capillary break layer with an impervious moisture barrier at least 10 mils in thickness. Floor slabs that are supported by site soils prepared in accordance with the "Site Preparation" section of this report or by structural fill should experience 'h inch or less of settlement. November J 2, 2007 ASSOCIATED EARTH SCIENCES, INC. SODh: -KEC4766BJ -ProjtCf.SllI)O(0166jKElWP Page 27 @! Vi i-f . l-~ . .:F( I I I I I • ! , ! ! I ! ! I i I I , i ! I 1 1 I l ~ j ~ 1 . j I , I II I I SITE STRUCTURES A Division of Kosnlk Engineering, PC EAST RENTON / ROSEMONTE Site Retaining Wall King County, Washington Structural Calculations for Permit Submittal Project No. S-08-040 April 25, 2008 1051119TH Ave SE, Suite C, Everett, WA 98208. (425) 357-9600 (phone). (425) 357·9622 (fax) East Renton / Rosemonte Site Retaining Wall Project No. S-08-040 STRUCTURAL CALCULATIONS INDEX Design Criteria 12' Retaining Wall Design 9' Retaining Wall Design Appendix A: Retaining Wall Section Excerpts from Geotechnical Report 01 02-05 06-09 Al A2-A4 '------------------------------------------------------ DESIGN CRITERIA Code: Permitting Agency: Foundation Design: East Renton / Rosemonte Site Retaining Wall 2006IBC King County Foundation design is based on the following values derived from the geotechnical report by Associated Earth Sciences, Inc. dated November 12, 2007: Allowable Bearing Pressure: 3,000 psf Lateral Earth Pressures on Vault Walls: Active Condition: 35 pcfEFW Seismic Addition: E = 4H psfUniform Passive Soil Resistance: 250 pcfEFW CF.S. = 1.5) Coefficient of Base Friction: 0.35 (F.S. = 1.5) Saturated Soil Density: . 125 pcf Vertical Loads Adjacent to Wall: 2' Sloping Soil Surcharge: 250 psfUniform ISO psfUniform Live Load Surcharge: Material Requirements: Rebar: Concrete: Grade 60 fc= 3000 psi SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date '1,-,z.!S-og prj. no, S-08-040 12' RETAINING WALL REINFORCING Active Pressure + Soil Surcharge + LL Depth to rebar center Comp block depth EFWa(pcf) Surcharge(psf) Soil Density(pcf) LF active LF surcharge 7.56 236 .1.6 \;6 # 6 H from t0l! I 2 :.. 4 5 6 7 8 9 10 II 12 13 14 15 H from top ai~@z~I~~~ Ms 62 271 662 1269 2129 3276 4745 6571 8789 11433 14540 18144 22280 26983 32288 Ms 18144 7852 Mu As 99 0,003 433 0,014 1058 0,033 2031 0,064 3407 0.107 5242 0.165 7592 0.239 10513 0331 14062 0,442 18293 0.576 23264 0,732 29030 0,913 35648 Ll22 43172 U58 51660 1.625 Mu As 29030 1.011 12563 0,437 Vertical Reinforcing: bar size: spacing: .j2 " ole As =' .0.44 sq in O!: 0.44.(' Footing to Wall Dowels: bar size: # 7 spacing: " olc As =. · .. 1,20 sq in O!: I.QJ tension conlrolled cracking: p S pt: p = 0,0100 pt = 0,0136 development length: 47,9 " in 3000psi cone Extend Dowels: 6,8 ft minimum into wall -> go to :'~4~i:~ii~17:ft.- end hook development: 13,4 " in 3000psi cone Embed Dowels: I U in min into footing -> go to ... "\,-, (13, in into 16 in ftg v Horizontal Reinforcing: bar size: # 5 spacing: . 12 11 ole each face: no :';;: p= 0,0026 " 0,0020./ SITE STRUCTURES 1051119th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosernont sheet date prj. no. S-08-040 12' RETAINING WALL REINFORCING Active + Soil Surcharge + Seismic Seismic Pressure Component Unifonn Lateral Earth Pressure ' 0:;1.' H psf - Load Factor for Seismic Pressure Component .,wallthiek . C~eteeover Rebar size Concrete Strength fc Depth to rebar center Camp block depth EFWa(pef) Surcharge(psf) , Soil Density(pcf) LF active::' ' LF surcharge" Vertical Reinforcing: " 10 in :,:iin 7 3090. psi 7.56 2.36 35 250 125 1;6 . 1,'6 bar size: # 6 H from top I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 H from top "':'12 '8.6 . , 48 psf ·':'1.00 Ms Mu As 65 89 0.003 283 395 0.012 689 972 0.031 1317 1877 0.059 2204 3167 0.100 3384 4896 0.154 4892 7121 0.224 6763 9899 0.311 9032 13284 0.418 11733 17333 0.545 14903 22103 0.695 18576 27648 0.870 22787 34025 1.071 27571 41291 1.299 32963 49500 1.558 Ms Mu As 18576 27648 0.962 8074 11853 0.413 spacing: '12 It ole As~ 0.44 sq in " 0.41 .,/ Footing to Wall Dowels: bar size: # 7 spacing: ' 6 " ole As ~ 1.20 sq in tension colltTolled'eraeking: p:!: pI: P ~ 0.0100 development length: 47.9 " in 300Qpsi cone Extend Dowels: 6.6 fi minimum into wall_ go to 7 fi ./ end hook development: 13.4 " in 3000psi cone " 0.96./ pt ~ 0.0136 Embed Dowels: 10.7 in min into footing -go to . -'. :'-~3 in into 16 in fig v' Horizontal Reinforcing: bar size: #' . 5 spacing: . ,~.2 " ole each face: no. 0.0026 " 0.0020./ SITE STRUCTURES 1051119thAveSE, SuiteC Everett, WA, (425)-357-9600 Project 12' RETAINING WALL REINFORCING Ha(ft)= 13.33 .. ' Hp(FT)=1.50 W(surchg)= 2000 WI (heel)= 7500 W2(waIl)= 1500 W3(toe)= 42 W4(ftg)= 1566 Wtotal-12608 EFWa(pcf)= 35 EFWp(pcf)=250 I,.t'\\> " FSpassive= 'J:,(>O Dsoil(pcf)= ·125.00 Surchg(psf)= ;400,00 Fsrchg(Jbs)= 1493 Fa(Jbs)= 3 III Fp(Jbs)= 281 Ffrict(Jbs)= 6682 FS sliding= -1.51-/ FS slide reqd= 1.50 I Net Sliding= -2359 Xcw(ft)= 3,04 Bcc-s(ft)= 1.88 Bcc-u(ft)= 2.81 East RentonIRosemont sheet date PD, no. I-f -2.-> -'" '( S-08-040 Active Pressure + Surcharge Tw(in)= 10 . Hw(ft)= 12, D(waI1)pcf-= ISO Tftg(in)= :,16,00 .' Wftg(ft)<f83 •..... Lheel(ft)= !~1QP' Ltoe(ft)= :g,20 D(ftg)pcf-=15.P Allowalbe Bearing Pressure '5:;":i.(3000 psf LF oveturn= 1.5:" '. Ms-ot(ft-Ib)= 23642 Mu-ot(ft-Ib)= 35463 D key(ft)= O.Ootf~/,}~ XresuIt-s(ft)= 4,91 Xresult-u(ft)= 5,85 Tr-s(ft)= 2.92 Tr-u(ft)= 1.98 3rd poinr-2.61 CASE= Service 'RESULTANT WITIDN MIDDLE 3rd Tr (ft)= 2,92 CASE= Ultimate Top bar cover (in)= . Top bar size = Top bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sg in)= '2 !W~:"(· . ,~,~:,~./;~~;:':;":;~,, ;-i'2'~_:" . ',' ,~~~ ~,; 13.56 U8 12,97 0.60 ./ TOE REINFORCING DESIGN Bot bar cover (in)-3 Bot bar size = 6 Bot bar spacing (in)= 12 ",,,,,':,,,',_ Depth to Reinf d (in)= 12.63 Comp Block a (in)= 0,87 d -al2 (in)= 12,19 As provided (sg in)= 0,44 / Lbrg(ft)-7,83 QI(psf)= 2841 ~ 3000 psf ,/ Q2(psf)= 380 RESULTANT OUTSIDE MIDDLE 3rd Tr Cft)= 1.98 Lbrg(ft)-5.94 Q I (psl)= 4245 ~ 1.5 x 3000 = 4500 psf ./ Q2(psf)= 0 W(surchg) + W(heel) + W(heel DL) (lbs)= 10500 Subgrade Reaction (lbs)= 5827 Load Factor = i.5:·' .' Mu= As reqd= As min = 1.33 x As reqd = Toe Reaction (Ibs)= W(toe) + W(toe DL) (lbs)= Load FactoF .i.5" , •... ,,_. Mu= As reqd = As min = 1.33 x As reqd = 29663ft-Ibs@wall 0.51 sqinperft 0.54 sq in per ft ,/ 0,68 sg in per ft 7051 441 13638 ft-lbs @ wall 0.25 sq in per ft 0.51 sqinperft 0.33 sq in per ft ,/ SITE STRUCTURES Project East RentonIRosemont 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 shee't date '1-~'? .~ prJ, no. 8-08-040 12' RETAINING WALL REINFORCING Active + Soil Surcharge + Seismic Ha(ft)= 1~j3 < Hp(FT)=J:SO . CoeFrict= 9:53 W(surcbg)= 1250 WI(heel)= 7500 W2(wall)= 1500 W3(toe)= 42 W4(ftg)= 1566 Wtotal= 11858 EFW a(pcf)=3~ . EFWp(pcf)=~5.o . FSpassive=I,OO Dsoil(pcf)= 125.00 Wseismic(psf)=,iS:06 Fsrchg(lbs)= 933 F seismic= 640 Fa(lbs)= 3111 Fp(lbs)= 281 Ffrict(lbs)= 6285 Tw(in)= 10 Hw(ft)= 12, ' D(wall)pcF -150 , Surchg(psf)= 250.00 ,.' Tftg(in)= i6.00 Wftg(ft)= 7,83 . , Lheel(ft)= 5.00, : Ltoe(ft)= 2,00 D( ftg)pCF 150 Allowalbe Bearing Pressure ::':", ·-}OOO psf LF oveturn= 1;25 ...... ; ..... Ms-ot(ft-lb)= 19620 Mu-ot(ft-lb)= 24525 FS sliding=L"Q 'y( FS slide reqd=i:41 .,/ Net Sliding= ·1881 D key(ft)=O,OO . Xcw(ft)= 2.81 CASE= Service CASE= Ultimate Ecc-s(ft)= 1.65 Ecc-u(ft)= 2.07 Xresult-s(ft)= 4.46 Xresult-n(ft)= 4.88 RESULTANT WITHIN MIDDLE 3rd Lbrg(ft)-7.83 Ql(psf)= 2149 $ 3000 psf ./ Q2(pst)= 879 Tr-s(ft)= 3.37 Tr-u(ft)= 2.95 3rd point= 2.61 Tr (ft)= 3.37 RESULTANT WITIflN MIDDLE 3rd Tr (ft)= 2.95 Lbrg(ft)-7.83 Q I (pst)= 2629 $ 1.5 x 3000 = 4500 psf ' Q2(psf)= 399 HEEL REINFORCING DESIGN Top bar cover (in)= Top bar size = Top bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -a/2 (in)= As provided (sq in)= 2 'J- 12 13.56 1.18 12.97 0.60 ,/ TOE REINFORCING DESIGN Bot bar cover (in)= Bot bar size = Bot bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sq in)= 3 6 12 12.63 0.87 12.19 0.44 ,/ . . -' . . W(surchg) + W(heel) + W(heel DL) (lbs)= 9750 Subgrade Reaction (lbs)= 6425 Load Factor =i,Cis ., Mu= As reqd = As min = 1.33 x As reqd = Toe Reaction (lbs)= W(toe) + W(toe DL) (Ibs)= Load Factor= 1.25 .... - Mu= Asreqd = As min = 1.33 x As reqd = 19761 ft-lbs @wall 0.34 sq in per ft 0.54 sq in per ft 0.45 sq in per ft ,/ 4283 441 6687 ft-lbs @ wall 0.12 sq in per ft 0.51 sqin perft 0.16 sq in per ft ,/ ,------ SITE STRUCTURES 1051119th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date 'i' t-~ . <"or prj. no. S-08-040 9' RETAINING WALL REINFORCING Active Pressure + Soil Surcharge + LL Wall thick Concrete cover Rebar size Concrete Strength fc Depth to rebar center Comp block depth :10 in ".2 in ;.6 3000 psi 7.63 0.87 LF active' . "'<"h6 LF surcharge c·· '·"·.I:6 Vertical Reinforcing: bar size: # spacing: jg' II ole Footing to Wall Dowels: bar size: # 6 B from tOE 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 B from top . -'9 "';,{:;::\t;g,~~ Ms Mu As 62 99 0.003 271 433 0.014 662 1058 0.033 1269 2031 0.063 2129 3407 0.106 3276 5242 0.163 4745 7592 0.237 6571 10513 0.32& 8789 14062 0.439 11433 18293 0.571 14540 23264 0.726 18144 29030 0.905 22280 35648 1.112 26983 43172 1.347 32288 51660 1.611 Ms Mu As 8789 14062 0.434 6175 9880 0.305 As= spacing: :.,d1 " olc As = Ji)14 sq in :!: 0.43./ . tension controlled cracking: p ~ pt: P = 0.0037 pt = 0.0136 development length: 32.9 " in 3000psi cone Extend Dowels: 3.9 ft minimum into wall ~ go to :,"Cu'c"':':"'; ft ./ end hook development: 11.5 " in 3000psi conc Embed Dowels: 11.3 in min into footing ~ go to ... ::i,Si,3 in into 16 in ftg ./ Horizontal Reinforcing: bar size: spacing: 12 " olc each face: no p= 0.0026 ~ 0.0020./ SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosernont sheet date prj. no. 7 9' RETAINING WALL REINFORCING Active + Soil Surcharge + Seismic Seismic Pressure Component Unifonn Lateral Earth Pressure ' 4 H psf- Load-Factor for Seismic Pressure Component H from top Depth to rebar center 7.63 Comp block depth 0.87 EFWa(pcf) , Surcharge(psf) Soil Density(pcf) ':' , 35 '250 , J25 LF active ',:', ' .. ' . :1.6 LF surcharge . . .1.6 Vertical Reinforcing: bar size: # 5 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 36 psf .j;oo Ms 59 259 635 1221 2054 3168 4598 6379 8546 11133 14177 17712 21773 26395 31613 Ms 8546 5993 Mu As 83 0.003 371 0.012 918 0.029 1781 0.056 3017 0.094 4680 0.146 6827 0.213 9515 0.297 12798 0.399 16733 0.522 21377 0.667 26784 0.835 33011 1.030 40115 1.251 48150 1.502 Mu As 12798 0.395 8931 0.276 spacing: 12 It ole As-0.31 sq in " 0.28./ Footing to Wan Dowels: bar size: # 6 spacing: "12 " olc As -0.44 sq in tension controlled cracking: p ~ pt: P -0,0037 development length: 32.9 " in 3000psi conc Extend Dowels: 3.7 ft minimum into wall-> go to A ft ./ end hook development: 11.5 " in 3000psi conc " 0.40'/ pI -0.0136 Embed Dowels: 10.3 in min into footing -> go to '13 in into 16 in ftg ./ Horizontal Reinforcing: bar size: spacing: each face: #.' 5 no ::-0.0026 0.0020 ./ SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont sheet date '-1-t.o; . ""'i: PI], no, S-08-040 9' RETAINING WALL REINFORCING Active Pressure + Surcharge Ha(ft)= ]0,33 .... Hp(FT)= \·SO ." CoeFriet= ]::53 . W(surchg)= 1532 WI (heel)= 4309 W2(wall)= 1125 W3(toe)= 28 W4(ftg)= 1200 Wtotal= 8194 Fsrchg(1bs)= 1157 Fa(1bs)= 1869 Fp(1bs)= 281 Ffrict(1bs)= 4343 Tw(in)=!O .' Hw(ft)=9' D(wall)pcf= i$o . ':":'." " Allowalbe Bearing Pressure LF ovetum= 1.5 Ms-ot(ft-Ib)= 12275 Mu-ot(ft-Ib)= 18413 Tftg(in)= 16,00 . Wftg(ft)= 6,00 " Lbeel(ft)= 3 .. 8.3., Ltoe(ft)= j.~4 . D(ftg)pef=lS0 3000 psf FS sliding= 1;~3'/ FS slide reqd= .LSil':;/.··.:,· D key(ft)= 'Q:o,iiXiiL:I:;Y;;i Net Sliding= -1598 Xew(ft)= 2.41 CASE= Service CASE= Ultimate Ecc-s(ft)= 1.50 Eec-u(ft)= 2.25 Xresult-s(ft)= 3.90 Xresult-u(ft)= 4.65 RESULTANT WITHIN MIDDLE 3rd Lbrg(ft)-6.00 Q 1 (psf)= 2600 s: 3000 psf ,/ Q2(psf)= 131 Tr-s(ft)= 2.10 Tr-u(ft)= 1.35 3rd point= 2.00 Tr (ft)= 2.10 RESULTANT OUTSIDE MIDDLE 3rd Tr (ft)= 1.35 Lbrg(ft)-4.04 Ql(psf)= 4055 s: 1.5 x 3000 = 4500 psf ,/ Q2(psf)= 0 HEEL REINFORCING DESIGN Top bar cover (in)- Top bar size = Top bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sq in)= 2 6 i2 13.63 0.87 13.19 0.44 .,/ " .. TOE REINFORCING DESIGN Bot bar cover (in)= Bot bar size = Bot bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (in)= As provided (sq in)= $ ':~--~~~:' .-~--:-:.;":" '?~-. ~~l~~~?~~""; 12.69 0.60 12.39 0.31/ W(surcbg) + W(heel) + W(heel DL) (lb.)= 6607 Subgrade Reaction (lbs)=. 3521 Load Factor =i.s Mu= As reqd = As min = 1.33 x As reqd = Toe Reaction (lbs)= W(toe) + W(toe DL) (lbs)= Load Factor-"L'S" ',.'. Mu= As reqd = As min = 1.33 x As reqd = 14483 ft-Ibs @ wall 0.24 sq in per ft 0.55 sq in per ft 0.33 sq in per ft./ 4524 295 5849 ft-Ibs @ wall 0.10 sq in per ft 0.51 sqinperft 0.14 sq in per ft ,/ SITE STRUCTURES 1051119th Ave SE, Suite C Everett, WA, (425)-357-9600 Project East RentonIRosemont ~;, .. sheet "1 -'---- date '1-;,..> . "'$ PI]. no. S-08-040 9' RETAINING WALL REINFORCING Active + Soil Surcharge + Seismic Ha(ft)~ :10.33 Hp(FT)~I.~O . EFWa(pcf}= J~:' ' EFWp(pcf)~:i5() . Tw(in)~Hj,< ... Tftg(in)= 16 . .00 Hw(ft)=~rc ' Wftg(ft)~i;'06 -;.. ,,~c~~f:::' : CoeFriet= 0.53 W(surehg)~ 957.5 Wl(heel)~ 4309 W2(wall)~ 1125 W3(toe)~ 28 W4(ftg)~ 1200 Wtota1~ 7619 FSpassive=!:.06 ... ' Dsoil(pcf)~ 12?;OQ Wseismic(psf)~ 36.00 . Fsrchg(lbs)~ 723 F seismic= 372 Fa(lbs)~ 1869 Fp(lbs)~ 281 Ffiict(lbs)~ 4038 D(wall)pcf= .ISO'" c __ Lheel(ft)~ 3']83 Surchg(psf)= 25Q,OO,' ",,:, Ltoe(ftF 1:34 D(ftg)pcf=lso ,', Allowalbe Bearing Pressure . " : '.:.'3000, psf LF oveturn= J~'~ ,> '.:. Ms-ot(ft-lb)~ 9509 Mu-ot(ft-lb)~ ll887 FS slidin~M6. '/', FS slide reqd~ t"Z' /- Net Sliding~ -1355 D key(ft)~9.00} c. Xcw(ft)~ 2.20 CASE~ Service CASE= Ultimate Ecc-s(ft)= 1.25 Ecc-u(ft)~ 1.56 Xresult-s(ft)= 3.45 Xresult-u(ft)= 3.76 RESULTANT WITIDN MIDDLE 3rd Lbrg(ft)-6.00 Ql(psf}= 1841 :5 3000 psf ./ Q2(psf}= 698 Tr-s(ft)~ 2.55 Tr-u(ft)~ 2.24 3rd point= 2.00 Tr (ft)~ 2.55 RESULTANT WITIDN MIDDLE 3rd Tr (ft)~ 2.24 Lbrg(ftF 6.00 Ql (psf)= 2238 :5 1.5 x 3000 = 4500 psf./ Q2(psf}= 302 HEEL REINFORCING DESIGN Top bar cover (in)- Top bar size ~ Top bar spacing (in)= Depth to Reinf d (in)= Comp Block a (in)= d -al2 (inF As provided (sq in)~ '2 -'6 .. "::: . ~-... -.. ;-. 12:, ."--. 13.63 0.87 13.}9 0.44 >/ TOE REINFORCING DESIGN Bot bar cover (in)- Bot bar size = Bot bar spacing (in)~ Depth to Reinf d (in)= Comp Block a (in)= d -af2 (inF As provided (sq in)~ 3 5 12 12.69 0.60 12.39 0.31 / W(surchg) + W(heel) + W(heel DL) (lbs)~ 6032 Subgrade Reaction (IbsF 4072 Load Factor =U5 ' ..... Mu~ As reqd= As min = 1.33 x As reqd ~ Toe Reaction (lbs)~ W(toe) + W(toe DL) (lbs)~ Load FactoF 1.25 Mu~ As reqd = As min~ 1.33 x As reqd ~ 9241 ft-lbs @ wall 0.16 sqinperft 0.55 sq in per ft 0.21 sginperft ./' 2501 295 2588 ft-lbs @ wall 0.05 sq in per ft 0.51 sq in per ft 0.06 sq in per ft '" I , I , , '5"'" A DMalon at Koanlk Englnaarlng PC 105111miAVESE,SUTTEC ',' EVEIIEIT. WASHINGTON 982UB '. , P!O.fCT lIIl.O fAST RENTON/ROSEMONT SHEET: SITE STRUCTURES 1 A OI.lllon ~I KOlnlk Enlllllnrlnll:~C_ PH: (426) -367 -9BDO FAX: '(426); ~ -9822 A1 ~-------------+----- W1 j L Tw L 1 1 Daoil: DENSITY OF THE SOIL IPCFI Dftg: DENSITY OF THE FOOTING IPCFI Dwall: DENSITY OF THE WALL IPCFI RETAINING WALL SECTION SCALE N/A ---------------------------------------------------------------- Rosemont-EaSI Remon Property King Cowuy, Washington · ,.. --.. -;'~"'~' .... Subsulface Exploration, Geologic Hazard, alld Geotechnical Engineering Repon Desigll RecommendatiollJ After the bearing stratum has been reached, the trench should be innnediately backfilled, We recommend the use of quarry spalls or 2-to 4-inch size crushed rock for backfill. The crushed rock must be tamped into place. to achieve a tightly packed mass; this may be done with either a "Hoepac" type compactor mounted on the excavator or more typically, with the bucket of the excavator itself. Staging areas should be maintained so that that rock is not contaminated by mud prior to placement in the trench. Equipment access to trench locations should also be maintained. Spread footings may then be used for building support when placed over properly constructed rock trenches that bear on medium dense to dense, natural soils. Footings which bear on approved rock trenches may be designed for an allowable bearing pressure of 3,000 pounds per square foot (psf) including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. However, all rock trenches must penetrate to the prescribed bearing stratum and no trenches should be founded in or above loose, organic, or existing fill soils. In addition, all footings must centered over the trenches and have a minimum of 14 inches for one-story structures, 16 inches for two-story structures, and 18 inches for three-story structures. Anticipated settlement of footings founded on approved rock trenches should be on the order of 1 inch. However, disturbed material not removed from footing trenches prior to footing placement could result in increased settlemems. All footing areas should be inspected by AES! prior to placing concrete to verify that the rock trenches are undisturbed and construction conforms with the recommendations contained in this report. Such inspections may be required by the governing municipality. Perimeter footing drains should be provided as discussed under the section on II Drainage Considerations." 11. 2 Shallow Foundations In areas where existing ftll is thin or absent, or where existing fill is removed and new structural fill pads are properly constructed, shallow spread footings may be utilized for building support when founded either directly on the medium dense to very dense, natural glacial sediments, or on structural fill placed over these materials. Natural sediments suitable for foundation support were generally encountered in our explorations at depths of approximately 0.5 to 2 feet, except in those areas described above where existing fill occurred. For footings founded either directly upon the medium dense to dense, natural sediments or on structural fill placed over these materials, \)Ie recommend that an allowable foundation soil pearing pressure of 3,000 psf be utilized for design pllTposes, including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. Perimeter footings for the proposed buildings should be buried a minimum of 18 inches into the surrounding soil for frost protection. Interior footings should be buried a minimum of 12 inches. All footings must penetrate to the prescribed stratum and no footings should be November 12, 2007 ASSOCIATED EARTH SCIENCES, INC. SGB/u -KED4766BJ -ProjIl!CI's\lOOof0766IKEtWP Page 25 ~ 11-J.<i . .?io r I I I I I I I 1 I 1 I \ I I ! I I I I I ----~~----------_._---------- -., '~:,.' .' . . ,. .. .. .. -. ,; ... ,,. ",-.' .' -.: Rosenwnt-East Renton Property King County, Washington , . . ' Sub.agoce Exploratloll, Geologic Hazard, and Geotechnical Engineering Repon DesiSN Recommendations founded in or above loose or organic soils. All footings should have a minimum width of 14 inches for one-story strucrnres, 16 inches for two-story structures, or 18 inches for three-story strucrnres. It should be noted that the area bounded by lines extending downward at IH:IV from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D 1557. In 8~dition, a 1.5H:IV line extending-down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed neaLIlle edge of steps or cuts in the bearing soils. Anticipated seUlement of footings founded as .described above should be on the order of * inch. However, disrnrbed soil not removed from footing excavations prior to footing placement could result in increased settlements. All footing areas should be inspeCted by AESI prior to placing concrete to verify that the design bearing capacity of the soils has been attained and that construction conforms to the recommendations contained in this report. Such inspections may be required by King County. Perimeter footing drains should be provided as discussed under the section on "Drainage Considerations." 12.0 LATERAL WALL PRESSURES All backfill behind walls or around foundation units should be placed as per our recommendations for structural fill and as described in this section of the report. Borizontally backfilled ",ails t~at are free to yield laterally at least 0.1 percenLof. their.l!eight may be. designed using an equivalent fluid equal to 35 pcf. Fully restrained, horizontally backfilled rigid walls that cannot yieid should be designed for all equivalent fluid of 50 pcf. If roadwayS, parking areas, or other areas subject to vehicular traffic are adjacent to walls, a surcharge equivalent to 2 feet of soil should be added to the wall height in determining lateral design forces. Walls that retain sloping backfill at a maximum angle of 2H:IV should be designed using an-equivalent fluid pressure of 55 pcf for yielding conditions or· 75 pcf for fully restrained conditions. . As required by the 2006 !BC, retaining wall design should include a seismic surcharge . pressure in addition to the equivalent fluid pressures presented above. Considering the site soilGand the recommended wall .backfill materials, we recommend 8 seismic surcharge pressure of 4H and 8H psf where H is the wal~ height in feet, for the "active" and "at-rest" loading conditions, respectfully. The seismic surcharge should be modeled as a rectangular distribution with the resultant applied at the mid-point of the wall. November 12, 2007 ASSOCIATED EARTH SCIENCES. INC. SGB/l$ ·KED4766BJ -Projw.r\zo/uo7661KElWP Page 26 Rosemont-Erut Remon Property King County, Washington .-. Subsuljace Exploration, Geologic Hazard, a11d Geotechnical Ellglneering Repon Deslen Recommendations The lateral pressures presented above are based on the conditions of a uniform horizontal ba.ckfill consisting of the on-site, natural glacial sediments, or imported sand and gravel compacted to 90 percent of ASTM: D 1557. A higher degree of compaction is not reconunended as this will increase the pressure acting on the wall. It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the walls. This would involve installation of a minimnm I-foot-wide blanket drain to within 1 foot of finish grade for the full wall height using imported washed gravel against the walls. A prefabricated drainage mat is not an acceptable substitute for the gravel blanket drain. 12.1 Passive Resistance and Friction Factors Lateral loads can be resisted by friction between the foundation and the natural glacial soils or supporting structural fill soils, or by passive earth pressure acting on the buried portions of the foundations. The foundations must be backfilled with structural fill and compacted to at least 95 percent of the maximum dry density to achieve the passive resistance provided below. We reconunend the following design parameters: • Passive equivalent fluid '" 250 pcf • Coefficient of friction = 0.35 The above values are allowable and include a safely factor of at least 1.5. 13.0 FLOOR SUPPORT Concrete, slab-on-grade floors may be used for the new buildings where the slabs are underlain by dense; natural soils or structural fill. We recommend crawl spaces·imd structural floors be used where foundations are supported on piles or rock trenches. -If crawl space floors are used, an impervious moisture barrier should be provided above the soil surface within the crawl space. Slab-on-grade floors should be cast atop a minimum of 4 inches of pea gravel or washed crushed rock to act as a capillary break. The floors should also be protected from dampness by covering the capillary break layer with an impervious moisture barrier at least 10 mils in thickness. Floor slabs that are supported by site soils prepared in accordance with the "Site Preparation" section of this report or by structural fill should experience 'f, inch or less of settlement. November 12, 2007 ASSOCIATED EARTH SCIENCES, INC. SGB/IS -K5047d6BJ· Pro)tmllOO4D761SjK£1WP Page 27 -- I I I .. II i I I ; I ~ l , I ~ j !" • • , , ~ t , • ~ t i • ~ ~ ~ ~ 1 .. ~ • • ~ f l t ~, r I ~ + ~ d ~ i ~ ~. , I I I I I I I I I I I I I I I I I I I I CAMWEST-EAST RENTON LEVEL 1 DOWNSTREAM ANALYSIS KING COUNTY, WASHINGTON ~~~(JV' I...J;:)Z\?c;cf.V)~ Date: 9119/02 Revision Date(s) 11110/04 Prepared By: Geoff E. Tamble, PE Tyson Wentz Reviewed By: Job # 01-047 Rebecca S. Cushman, PE .----------------------------- I I I I I I I I I I I I I I I I I I I Prepared By: CAMWEST -EAST RENTON Levell Downstream Analysis King County, Washington Prepared For: CamWest Real Estate Development, Inc. Issued September 19,2002 Revised November 10, 2004 GeoffE. Tamble, PE Tyson Wentz Reviewed By: Rebecca Cushman, PE I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS PROJECT OVERVIEW ...•......................................................................•................................................•.. 3 GENERAL DESCRIPTION OF PROPOSAL ........................................................................................................ 4 PREDEVELOPED CONDITION OF SITE ........................................................................................................... 4 DEVELOPED CONDITION OF SITE ................................................................................................................ 4 OFFSITE STORM WATER RUNOFF ................................................................................................................. 5 DRAINAGE BASIN, SUBBASINS AND SITE CHARACTERISTICS ....................................................................... 5 OFF-SITE ANAL YSIS ................................................................................................................................. 6 STUDY AREA .................................................................. , ........................................................................... 6 TASK 1, STUDY AREA DEFINITION AND MAPS ................................... : ........................................................ 6 Onsite Basin .... .6 Upstream Basin. .. .................... 6 TASK 2, RESOURCE REVIEW ....................................................................................................................... 7 TASK 3, FIELD INSPECTION ......................................................................................................................... 7 TASK 4, DRAINAGE SYSTEM AND PROBLEM DESCRIPTION ......................................................................... 8 TASK 5, MlTlGA nON OF EXISTING AND POTENTIAL PROBLEMS .................................................................. 8 APPENDIX .................................................................................................................................................... 9 Preliminary Plat Map Existing Conditions Exhibit Developed Conditions Exhibit Soils Map Soils Legend Table 3.2.2B -Equivalence between SCS Soil Types and KCRTS Soil Types King County Drainage Basins (Figure 2) Study Area Maps (1990 King County Sensitive Areas Map Folio) Wetlands Streams and 100-Year Floodplains Erosion Hazard Areas Landslide Hazard Areas Seismic Hazard Areas Coal Mine Hazard Areas King County iMAP Drainage Complaints Maps Drainage Complaint List and Complaints Downstream Drainage Exhibit King County Off-Site Analysis Drainage Table TRIAD ASSOCIATES -LEVEL I REPORT FOR CAMWEST, EAST RENTON PAGE 2 I I I I I I I I I I I I I I I I I I I PROJECT OVERVIEW This section gIves an overvIew of the project site in both the pre-developed and developed condition. There is also a description of the runoff characteristic of the property and the existing soil classification. The proposed project consists of a Single Family Residential Development for 66-lots on 15.92 acres in an R-6 zone. The site consists of two existing lots that total approximately 19.6± acres, with approximately 8.2± acres of sensitive areas to remain undeveloped that include a wetland (please reference Preliminary Plat Exhibit in Appendix). The project is generally located west of the intersection of 148 th Ave SE and SE 120th St. in King· County; Section 10, Township 23 north, Range 5 east, W.M., Washington State. ~ TO T Vicinity Map NOT TO SCALE ST i:;j ~ « oS a ~ PARK & RIDE TRiAD ASSOCIATES -LEVEL I REPORT FOR CAMIVEST, EAST RENTON PAGE] I I I I I II I I I I I I I I I I I I I GENERAL DESCRIPTION OF PROPOSAL In general, this project will replace one existing single-family home, a shop, a small covered storage building, and a gravel driveway with 66 single-family lots. Part of the major site improvements will include the installation of neighborhood access streets (sub- collector, sub access, and minor access). 14Sth Ave SE will be improved with full half street improvements as required by the King County conditions of approval (To be determined). All runoff from the site and the frontage improvements will be collected in the proposed conveyance system. Detention and water quality will be provided according to King County Standards. Two drainage facilities are proposed, one for each drainage basin. A vault is proposed to be located in the northwest comer of the site and a pond at the northeast comer of the proposed project of Rosemonte, adjacent to the north of E. Renton. The dimensions of the proposed lots and roadways will require buffer averaging on the western portion of the site. PREDEVELOPED CONDITION OF SITE The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blackberries, and trees (See the "Existing Conditions Exhibit" located in the Appendix). The site has two drainage basins, one that generally drains towards the northwest and the other that drains to the west. A wetland occupies the western portion of the site where the two basins combine then flows to the north through Honey Dew (Honey) Creek. Overall, the site slopes from east to west at approximately 5-15%. The site generally slopes from 14S th Ave SE down to the west towards Honey Dew Creek. DEVELOPED CONDITION OF SITE The developed site improvements will be located on the eastern 15.92 acres of the property (See the Developed Conditions Exhibit located in the Appendix). The preliminary plan shows 66 single-family lots with subcollector, sub-access and minor access roadway improvements. 14Sth Ave SE will be improved with full half street improvements as required by the King County conditions of approval (To be determined). The detention/water quality facilities will be designed to meet the Level I Detention TRIAD ASSOCIATES -LEVEL IREPORT FORCAMWEST, EAST RENTON PAGE 4 I I I I I I I I I I I I I I I I I I I Standards and the Basic Water Quality Menu from the 1998 King County Surface Water Design Manual. OFFSITE STORMW ATER RUNOFF Flows entering the site from the east come from the west half of 148 1h Ave SE. Runoff entering the site from the west and south adjacent to the wetland is collected in the wetland area. The wetland area will remain undeveloped. Runoff generally does not enter the site along the north and south property lines near the proposed lots since the site slopes from east to west. DRAINAGE BASIN, SUBBASINS AND SITE CHARACTERISTICS The existing site has two drainage basins that drain into Honey Dew (Honey) Creek which, according to the December 1990 King County Sensitive Areas Map Folio, is an unclassified stream in the May Creek Sub-Basin. Honey Dew Creek combines with May Creek over two miles downstream (north) of the site. May Creek is in the Cedar River Drainage basin and ultimately discharges into Lake Washington. The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blackberries, and trees. Most of the trees are located in the western half of the site with the pasture area occupying the eastern portion. The blackberries are located throughout the property. According to the King County Soil Survey, refer to the Soils Map and Legend in the Appendix. The site is underlain with AgC (Alderwood gravelly sandy loam, 0 to 6 percent slopes) and AgB (Alderwood gravelly sandy loam, 6 to IS percent slopes) soils belonging to the S.C.S. type 'c' hydrologic group or 'Till Soils'. Onsite topography is mild to moderate, sloping to the west at approximately 5% to 15%. Note: The 1990 King County Wetland Inventory did not list the wetland on this property. The 1987 Basin Reconnaissance Program did not list Honey Dew (Honey) Creek in any of its basin reconnaissance data. TRIAD ASSOCIATES -LEVEL I REPORT FOR CAMWEST, EAST RENTON PAGES ..... _._. --------------------- I I I I I I I I I I I I I I I I I I I OFF-SITE ANALYSIS This section outlines the drainage basin, within which this project is located, highlighting the downstream conditions one mile from the project site. STUDY AREA TASK 1, STUDY AREA DEFINITION AND MAPS This site is located within the May Creek Sub-Basin of the Cedar River Basin. On site Basin The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blackberries, and trees. Most of the trees are located in the western half of the site with the pasture area occupying the eastern portion. The blackberries are located throughout the property. According to the King County Soil Survey, refer to the Soils Map and Legend in the Appendix. The site is underlain with AgC (Alderwood gravelly sandy loam, 0 to 6 percent slopes) and AgB (Alderwood gravelly sandy loam, 6 to 15 percent slopes) soils belonging to the S.C.S. type 'C' hydrologic group or 'Till Soils'. Onsite topography is mild to moderate, sloping to the west at approximately 5% to 15%. Upstream Basin Approximately half of 148'h Ave SE along the entire site frontage currently sheet flows into the site. Flows from the frontage improvements will be collected and conveyed to the proposed detention/water quality facility. The area where flows enter the site from the south and west adjacent to the wetland will remain undeveloped. TRIAD ASSOCIATES -LEVEL I DOWNSTREAM ANALYSIS FOR CAMWEST. EAST RENTON PAGE 6 I I I I I I I I I I I I I I I I I I I I TASK 2, RESOURCE REVIEW "1998 King County Surface Water Design Manual" "1990 King County Sensitive Areas Map Folio" "1973 King County Soil Survey" There are no apparent problems associated with this project. TASK 3, FIELD INSPECTION "Triad Associates" preformed a field visit on 4/03/01 to locate any potential problems upstream or downstream of the proposed development. The weather was overcast and approximately 55 degrees with small amoimts of runoff in the drainage systems from the previous day's rainfall. See the "Downstream Drainage Exhibit and Table" located in the appendix for a complete definition of the Study Area. Drainage leaving this property is collected in an existing wetland (A) and conveyed offsite to the north through two 12" CMP culverts (B 1 & B2). The onsite wetland has a slight ridge separating the wetland on the north property line of the site. The runoff that leaves the through the two 12" CMP culverts combines in a drainage ditch adjacent to the north property line (C). Drainage also leaves the site on the north east side (C2) then drains west and intersects with the drainage from C 1. From here the runoff flows to the north through a natural drainage course called Honey Dew (Honey) Creek (D) for about 500' before entering a 24" CMP private driveway culvert (E). The property owner adjacent to the culvert stated that it has only flooded once, around 15-years ago, when a neighbor downstream of their property dammed up the creek to make a waterfall. The waterfall has been removed and the culvert has not flooded since that time. From this culvert, the natural drainage course continues to the north in a well-defined channel with heavy ground cover (F). The final observation of the downstream investigation was approximately 2000' downstream of the site (G). No evidence of flooding or major erosion was observed along the downstream drainage course during the site visit. From the last observed point in Honey Dew (Honey) Creek (G), runoff continues north then west before combining with May Creek and eventually reaching Lake Washington about 6 miles to the West. TRIAD ASSOCIATES -LEVEL I DOWNSTREAM ANALYSIS FOR CAMWEST. EAST RENTON PAGE 7 I I I I I I I I I I I I I I I I I I I TASK 4, DRAINAGE SYSTEM AND PROBLEM DESCRIPTION "King County Water and Land Resources (WLR) Division Drainage Complaints" King County suggests not following up on any complaints before 1990 due to their age and development that has occurred. Complaints Nos. 94-1000, 95-009, 96-0185 and 96-552 all pertain to one parcel (9353). The majority of the complaints pertain mostly with drainage runoff from 148th Ave SE. In particular, an existing ditch was discharging into this property and flooding the basement. King County performed a study of the situation under the Neighborhood Drainage Assistance Program (NDAP) and recommended the installation of a catch basin with a 12" conveyance system to direct the flows away from the home. This project was not completed by the County; however, the home owner installed a similar pipe system as recommended by the County prior to February of 1996. Therefore, the NDAP study was cancelled. Complaint #96-0552 was due to a broken fire hydrant (vandalism), not stormwater, and therefore closed. Additional complaints are within the I mile radius of the project site but are not in the downstream drainage path. The complaints are linked to a private home drainage system and a private road washout" due to no drainage system rather than flooding, or erosion of the large drainage course that the site will discharge to. TASK 5, MITIGATION OF EXISTING AND POTENTIAL PROBLEMS The developed site runoff will be detained to the Level I standard as outlined in the King County Surface Water Design Manual -1998. The KCRTS Levell detention standard requires maintaining the high flows at their pre-development levels for all flows greater than the 2-year peak flow up to the IO-year peak flow. The site is proposing to utilize two detention systems. The detention facility release rates will be based on the existing runoff from the area of the site that is being developed. The wetland area and associated buffers will remain undeveloped. One half of 148'h AVE SE frontage will be picked up in the conveyance system along the site frontage reducing flooding discussed in the drainage complaints. 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" .. -.~- j!J )O!Jao -ZOQro - ""'~ 'lsq-dLYOI 'L IXII )noA07 '6MP'ldnLYOI "JOu/WI/OJd\ So/1j 6M O\LYOIO\Sl:JJfOijd\ .3 _ _ _ _ _ _Oyq_ YO~ A~IU"_ -- W -l « () CJ) ""1', .... , > " .. -"';", o - -., ""I (j) OJ c- '" G o ~ l' a "-I'< >-, " o o N © I - 1 1 1 lit : ;;:-'I!!.~-::::==d...Fi~ ••• = •••• 1 1 I I 1 1 1 I , " • ',II -.~ EvB Py AkF ------------------------------------------------ -. GUIDE TO MAPPING UNITS ~or. a .full description of a nmpping unit~ read both the description of the mapping unit and that of the soil series to which the mapping unit belongs. See table 6. page 70, for descriptions of woodland groups. Other I infonation is given in .tables as follows: Acreage and extent) table 1, page 9. Engineering uses of the soils. tables 2 and 3, I pages 36 through 55. Town and country planning, table 4. page Recreational uses, table 5, page 64. Estimated yields, table 7, page 79. 57. Map Described on I ymol Mapping unit , AgB_Alderwood gravelly sandy loam, 0 to 6 percent.slopes---------- to AgC-Aldenmod gravelly sandy loam, 6 to 15 percent s lopes--------- ~D Alderwood gravelly sandy loam, 15 to 30 percent slopes-------- F Alderwood and Kitsap soils, very steep------~~--------------- ~B Arents~ Alderwood material, 0 to 6 percent slopes !I--------~~ Am( Arents, Alderwood material, 6 to IS percent slopes 1/--------- f. A.rents, Everett material !/-------------:-----------=----------- C Beausite gravelly sandy loam, 6 to IS peTcent slopes---------- eD Beausite gravelly sandy loam, 15 to 30 percent slopes--------- BeF Beausite gravelly sandy loam, 40 to 75.percent slopes--------- Bh Bellingham silt loam------------------------------------------luT Briscot silt loam--------------------------------------------- Buckley silt loam--------------------------------------------- Cb Coastal beaches----------------------------------------------- Ea Earlmont si-l t loam-------------------------'---- ---------------1I:d Edgewick fine sandy 1oarn-------------------------------------- ~B Everett gravelly sandy loam, 0 to 5 percent slopes------------ . Eve Everett gravelly sandy loam,S to )5 percent slopes----------- EvD Everett gravelly sandy loam, 15 to 30 percent slopes---------- I Ewe ·EV:~~;~~~~~~~~~~-~~~~~~~-~~~~-~~~~-~-~~-~~-~~~~~~~---___ _ . InA Indianola loamy fine sand, 0 to 4 percent slopes-------------- InC Indianola loamy fine sand, 4 to 15 percent slopes.------------- '-.. f) Indianola loamy fine sand, 15 to 30 percent slopes------------'I Kitsap silt loam, 2 to 8 percent slopes----·-----------~----- : hy~ Kitsap silt loam, 8 to 15 percent slopes---------------------- , KpD Kitsap silt loam. IS to 30 percent slope5--------------------- KsC Klaus gravelly loamy sand, 6 to 15 percent slopes------------- '~:C ~!~~~o~l!~~a~r!~~~;-i~~-~~~~~-;-~~-i;-~~;~~~~-~;~~~~=====~ '~g Newberg silt loam·-------------------------·~----------------- It;. Nool:.s ael:. si It: loam------- ---'---.--------------- ---------------- '~NO ~rma sandy loam---------------------------------------------- Orcas peat---------------------------------------------------- Oridia silt loam---------------------------------------------- OVC Ovall gravelly loam. 0 to IS percent slopes------------------- OvD Oval I gravelly loam, IS to 25 percent slopes------------------ '~F Ovall gravelly loam, 40 to 75 percent slopes------------------ lI~c Pildhuck loamy fine sand--------~~---------------------------- Pk Pilchuck fine sandy loam-------------------------------------- Pu Puget silty clay loam-----------------------------------------E' Py Puyallup fine sandy loam-------------------------------------- aC Ragnar fine sandy loam, 6 to 15 percent slopes---------------- aD Ragnar fine sandy loam, 15 to 25 percent slopes--------------- RdC Ragnar-Indianola association, sloping: 1/---------------------- ~dE Ragna~~~~~;::~~~~~~:~~~~~=~~~~~~~;;=~~~~~;=i7============ Ragnar soil---------------------------------------------- I Indianola soil------------------------------------------- ,I page 10 8 10 10 10 10 II II 12 12 12 J3 13 14 14 IS IS 16 16 16 17 16 17 17 18 18 .18 18 19 19 20 20 21 21 22 23 23 23 23 24 24 25 26 26 26 Woodland Capability l.D1i t group Synbol Page Synbol IYe-2 76 3d2 IYe-2 76 3dl Vle-2 78 3dl VJJe-1 78 2dl IYe-2 76 3d2 IVe-2 76 3d2 IV5-1 77 3f3 IVe-Z 76 3d2 VIe-2 78 3dl YJJe-1 78 3dl IIlw-2 76 3w2 IIw-2 75 3wl 11 Iw-2 76 4wl VIIlw-1 78 IIw-2 75 3w2 IIlw-1 7S 201 IVs-l 77 3f3 VIs-l 78 3£3 Vle-l 77 3f2 VIs-! 78 3f3 IVs-2 77 453 IVs-2 77 453 VI e-! 76 452 II I e-l 7S 2d2 IVe-l 76 'd2 VIe-2 78 2dl Vls-! 78 3f1 Vlw-2 78 201 Vls-! 78 3f3 llw-I 74 201 Jlw-! 74 201 II Iw-3 76 3w2 VJJIw-1 78 lIw-2 75 3w1 IVe-2 76 3dl Vle-2 78 3dl VJJe-1 78 3d1 Vlw-l 78 251 IVw-1 76 251 I1lw-2 76 3w2 IIw-! 74 201 IYe-3 77 451 VJe-2 78 451 -------- IVe-3 77 451 IV5-2 77 453 .------- Vle-2 78 451 Vle-I 77 452 I u. s. COVER1fME1lT PRINTING OTT1CE: J9'l3 0·468.266 I !I II • I • I I ;. I I :. :1 :1 :. 3.2.2 KCRTSIRUNOFF FILES METHOD -GENERATING TIME SERIES TABLE 3.2.2.B EQUIVALENCE BETWEEN SCS SOIL TYPES AND KCRTS SOIL TYPES SCS Soil Type SCS KCRTS Soil Notes Hydrologic Group Soil Group Alderwood (AgB, AgC, AgO) C Till Arents, Alderwood Material (AmB, AmC) C Till Arents, Everett Material (An) B Outwash 1 Beausite (BeC, BeD, BeF) C Till 2 Bellingham (Bh) 0 Till 3 Briscot (Br) 0 Till 3 Buckley (Bu) 0 Till 4 Earlmont (Ea) 0 Till 3 Edgewick (Ed) C Till 3 Everett (EvB, EvC, EvO, EwC) AlB Outwash 1 Indianola (InC; InA, InO) A Outwash 1 Kitsap (KpB, KpC, KpO) C Till Klaus (KsG) C Outwash 1 Neilton (NeG) A Outwash 1 Newberg (Ng) B Till 3 Nooksack (Nk) C Till 3 Norma (No) 0 Till 3 Orcas (Or) 0 Wetland Oridia (Os) 0 Till 3 avail (OvC, OvD, OvF) C Till 2 Pilchuck (Pc) C Till 3 Puget (Pu) 0 Till 3 Puyallup (Py) B Till 3 Ragnar (RaC, RaO, RaC, RaE) B Outwash 1 Renton (Re) 0 Till 3 Salal (Sa) C Till 3 Sammamish (Sh) 0 Till 3 Seattle (Sk) 0 Wetland Shalcar (Sm) 0 Till 3 Si (Sn) C TIll 3 Snohomish (So, Sr) 0 Till 3 Sultan (Su) C Till 3 Tukwila (Tu) 0 Till 3 Woodinville (Wo) 0 Till 3 Noles: 1 . Where outwash soils are saturated or underlain at shallow depth «5 feet) by glacial till. they should be treated as till soils. 2. These are bedrock soils, but calibration of HSPF by King County DNR shows bedrock soils to have similar hydrologic response to till soils. 3_ These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water table. In the absence of detailed study, these soils should be treated as till soils. 4. Buckley soils are formed on the low·permeability Osceola mudflow. Hydrologic response is assumed to be similar to that of till soils. ,. 1998 Surface Water Design Manual 911198 3·25 11·--.. _---._.----------_. --_. __ ._._._-------------_ .. ,. , ::" _.", j' ~i "I .,.".. . "."j ", "( I . I "II I, /' . '. -. I :n .1·· :n ,", ~ :' T"' ... ,~ I ··1:· ... ";. . , ; .'. iIi I ... · " I I , ;J' Ii , , /.,' . ... ( , '\ 1,( , I, i , \ ,'1>, •. , .. - J • i ,. ." { . .\ ,. Jl. . \ ii, .-~ !." • . ,', , '.'~ .j ••.• ~ .'\' ....• ; I ~ ... ,IIJ,/ .• ,.' . =1, ~!~. _ :: ,.j ~ ~I&.; ... ;~ ,I.'JJ. laj' ':; I J~'f :" I .. ~il'; .-JJ .. ~" o .. . .... ,--' ,,:, CI _ ...... ~ • .': .i ',' iI: #'f#It;"c "'J .A .... ; ", c I, ~. If. '. ·~·.,.r ~;:""'" /' .... /' :; 'TIl I' " ':"'i !. !' ','" '.," d' ; ~ 1'- U . ~: 1 " " "/.( " ,t. -'. : I '""." " j ..... " ,i/,'';' .~ . "t'· 'If ji , . , '\ li; i. 'il II;;' '. " -. - --. -, -. ---- N i .~ ~ - CI) Z -~ : &. ;8" -~ Q '''t·· .'..; \- .\ C!J « z < a: o , -·':-1 l /I ... 1'-" \ \. I , !' J 1::-; 1::-~ {g <E CO H c: -0 ::J c: !~ s :J S > III c: it ~ c: ~ '-'. !':!: ><.2 ... 0 .b "0 8"-'iij' :J "t ::E rJ) h I ~:~'~'.~ .-.. _\ ...... "..1.,. I i . , .,' ~:'~' ,: ( ...... II 1.1 i -- - -- - -- ... - ~ ~ .. ~ .. '" • ~ " 0 .; '! I - I .. ..: .1: _: I!!IIt -. -. III!!!...: _ ... --.: "'-= --. --~ ~ -~ ~ -... ~ - -~ -~ -~ -~ --- 1-··-- 1 ::t= I I I 1=1 : o I ..... tI.Il tI.I C':! I e~1 ~<r;1 o I , i ,) , ,. -. -. -. -. -. -. --. ------ - - - I , i , I 0) I I I r , J:: .-. '" !'1 po n :l 0.· .... . ..... C" ~ N I -- I I I I I I -I - -. -. ---. -. -. -. -. -. -- - - , . o --. -- 'W ...J ~ I \ i .i , I i ! i - -. -. -. -. -. -. -. -. -. - - ----- -- - -'-- -I i ! ' i. ----------. --- ----- ------------- Basin: Cedar River -- Symbol Drainage Component Type Name, Size Type: sheet. swale. see map stream, channel, pipe, pond; Size: diameter, surface area C1 Honey Dew (Honey) Creek C2 sheet flow 0 Honey Dew (Honey) Creek E 24" CMP Culvert F·G Honey Dew (Honey) Creek OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Subbasin Name: May Creek ------------------------. Drainage Component Slope Distance Existing Potential Description from site Problems Problems discharge consbictions; under'capacity, pondlng drainage basin, vegetation, % 1/4 mi = 1320ft overtopping. floodlng.habltat or organism cover, depth, type of sensitive destruction. scouring. bank sloughing. area, volume sedimentation, incision, other erosion 3-4' wide drainage'channel 0.5% 10 ft None None pasture 5-15% .14 mile none none 3-4' wide drainage channel 0.5% 480ft None None 2-3' of cover under driveway 0.5% SOOft None None 3-12' wide drainage channel 0.5% soo· 2000 ft None None Triad Associates Subbasin Number: ---------- ---- Observations of field inspector resource reviewer, or resident tributary area. likelihood of problem. overflow pathways. potential impacts. unobstructed natural and man altered drainage channel erosion unobstructed natural and man altered drainage channel if culvert overflows, it will cause no damage to private structures broad drainage channel with heavy I vegetation on both sides of channel ---' --.. :11 .. .. . .. . ---- -- -- ----,--E1: \O-23-~ RENTON ~ \ - . .-. - -OV~. -,al 'al ,-t·J · ____ I ~E -'. . .:. -==----::=.: -~ .. yT __ .. __ ... _______ ,_. "+: ___ _ , =MI' §.7-'-' -~ , ~ , -' -'.-' EiDii'l'l-''=':;f.= '.:E' 7.E "'.86' ""'To '=' .. ':-::T.'..,. .. ;:-t:": . ·f: ~_ ........ n 0: ........ nlc'''''D..,;V _~.~ ' ..•. ,)1 -)"-_-•• _ --"f .... sri I . 07 ISJ,l J \ c. T ® "l1EiJ John' Hansen 2,86 Ac. :: Wm. E, Broyles 191 Ac. /lifE) IIZ@ Ge.orge: C Dayi 5 2 ISAC. IIl]~ rG:i'ke . H aye r 2Yl Ac. IIIl (D Frdn(IS p, Brown 4.17 Ac. G Floyd w. Shaff, ei ux Ie)' J. Petersen @)(!l o. ~l3 A c, Citizen Fed. S.l( L, Assn. 4.14 Ac. 4,SS Ac. 12 ) S,P.666009 @J II II :< :11 1141 iJ II @ I .. ,---------~~\ J. 8'J .r. a9200e R ~ /:1 ® w lC (Jl IIt2E) 111m! Henr~ lJro 4.77 Ac. ® I"IE) Robert l..Stdrzman 2. SO tic. ® Theodore L. Binder ~ ~ Li one I Lesh \ '1 Knu+e A. [)eckstrom 5 Ac. E (II cf67 Ac, -~'s .@> [3J' .. 'I', <f.5b Ac'rd :\': l!!±ji1 'b ; : 1'0. : 'I. '~n : : O,SOAC, l!!!J<1 I" ~ ISO I i .a,s,J .. "~,, ,,J,,," _ John M. Pollock First SdV, & Loan Assn, 4,10 Ac 631.P .. 1 {31 -------------®I\I :)11 '0 0 "1 5.34 Ac, 24" CMP CULVERT , __ .,2'" :1 ' , ::: '.' \11 I,,' I.,' ::: 118 8 (I) S.P. 778111 121 + N 1 1"=200' 1"/024 C{j<1 Ac, . ® I Chas, H. Moore 385 AC, O.<1S Ac, @; ~ @ III C1 ~. :0 =(.)/' , ~ ~, If,-~ C2 1 '" ~ 12" CMP CULVERT' '. ~ ; I: i i j i Donald R. Larsen 4.'J0 Ac, l'BJi,i , . '-'-~::'--"-''''!,." \~, (.' \I,1nr~ W r;rihhl,.. 1'+ "' ? ~q Or ~I:: Henry W Owens 3,93 Ac. 0''' DOWNSTREAM DRAINAGE EXHIBIT @1ol.~· ." ,0 (jj§ :' ~ ,. "'Jiil 1 [::1'1' = I Map Output Page 1 of 1 I ®Klng County ~ __ Comments I I I I I I I ., ". I' I I • 1'/ Legend The Buffflr """ I III Buffemd SelectiOn 0 Paroats " -County Boundary 0 lake$. and Large RNtll's i tv\;Ie ~a.d\~s , -" Slmets /.,/ Streams I ~ "-• IM.RD Drainage Co"lllaints --I""") i sources i i I accuracy, completeness, timeliness, or rights to the use of such liable for any general, special, incidental, or consequential damages including, but not limited to, from the use or misuse of the information contained on this map. Any sale of this map or information on I By visiting this and other King I I I ~-"_::_""::"_'---=--'-C "-- http://www5"metrokc"goy/serylet/com"esri"esrimap. Esrim ap ?Sen'iceName=oyeryiew &Clie ... ----------------------------------- 11/4/2004 I Map Output Page 1 of 1 I @)Klng County ~~ Un,i',,",!d I I I I I I I I I I I , -0 Legend 1_' County Boundary Parcels StftlGts. III Incotp(Jl'atGd Ama ~ "-0 lakGs and Large RilIers ....... 1./ Stmam!> I /\/ """ III 'M..RD Q-ainage Complaints i map I makes no representations or warranties, express as to accuracy, completeness, timeliness, or rights to the use of such Info,rr,a';"n: County shall not be liable for any general, special, indirect, incidental, or consequential damages including, but not limited to, rev,emJesor lost profits i from the use or misuse of the information contained on this map. Any sale of this map or information on ; I I By visiting this and other King County web pages, you expressly agree to be bound by terms and conditions of the site. The details.,. I I I I I I I I I I I • I I I • I I I • • Camwest -E.Renton Drainage Complaints Complaint Status Problem Type Rae Date TB PADD PADDl PADD No SUF 1995·0009 CLOSED EROSION C Thu. 5 Jan 199500:00:00 35E4 14701 116TH ST 1996-0185 CLOSED FLOG C Thu, 8 Feb 1996 00:00:00 35D4 11625 148TH AVE SE 11996.0552 CLOSED FLDG C Frl, 23 Feb 1996 00:00:00 35D3 11615 148TH AVE SE 1996·0552 CLOSED FLDG R Thu, 14 Mar 1996 00:00:00 35D3 11615 148TH AVE SE 1989-0776 CLOSED FLDG C Mon,4 Dec 198900:00:00 3504 11644 142ND AVE SE 1999-0151 CLOSED DRAINAGE C Mon, 22 Feb 1999 35D4 11624 142NDAVE SE 00:00;00 Complaint PADD Status Problem Type Ree Date TB PADD PADD 1 No SUF 1988·0790 CLOSED DRNG C Fri, 23 Dec 1988 35D3 14418 116TH ST 00:00;00 1989-0140 CLOSED EROSION C Tue, 14 Mar 1989 35D3 14429 116TH ST 00;00;00 1989·0150 CLOSED DRNG/ERO C Wed, 15 Mar 1989 35D3 14428 116TH ST 00:00;00 1994·1000 CLOSED FLOODING C Thu, 29 Dec 1994 35E4 11615 148TH AVE SE 00;00:00 1994·1000 CLOSED FLOODING NDA Wed, 22 Mar 1995 35E4 11615 148TH AVE SE 00;00:00 1994·1000 CLOSED FLOODING RN Tue, 10 Jan 1995 35E4 11615 148TH AVE SE 00:00:00 -----.----- PIN NTB 1023059357 627A7 1023059354 626J7 1023059353 626J6 1023059353 626J6 1023059060 626J7 1023059092 626J7 PIN NTB 1023059362 626J6 1023059004 626J6 1023059363 626J6 1023059390 627A7 1023059390 627A7 1023059390 627A7 .... _.::. __ ::c.:_:,'-,-'_. ____ . __ .... _. ___ . _ ----~-._--_.-----_ ... ----~--~----. ---------------_._--------- ~: .;.~V. 8.2004-10;:: CO::~R:URFACE WATER MANAGEMENT DIVISI~N~.339 1 'I 'It, ~' ~ . DRAINAGE INVESTIQATION REPORT Page 1: INVES11GATION'REQUEST . P.4/20 ,. ,$ Typ8_.;....(!_ Reool\ied by; , I. ~~ Date: /.,:? ¢. OK'd by: ;tit FOe 'No. f(..-Io 00 RBCfIived from: (P1o_ p~nt plainly for acannlng), (Day) (eIo) .J • PHONE £f5'~ ;?.J> S~ __ _ City &"#7 t.Jt<d State Zip 1ft "s-~ (cation Of problem, If different: eported Problem: 1 1 1 I' ilatname: ~her agencies Involved: p . 11£ -.l!L....zL~ Parcel No. IO:J!'aS.. "lU3 1 1/4 S T R .. Basin 11tH,! CouncD Disl Charge No: I/SPOSITION: by:1!i Lot No: Block No: No FIeld Investigation NeSded __ _ KroII __ _ TIT.Bros: New ~'Z 7 I} 7 Old ~S"£~ " OR: No further action recommended because: .. '. _ Lead agency has been notlfled: r-Problem has been corrected. -_-rl'No=-:::pro=bI'::':em=ha""s-':b~e~en:-;l~de""nt""lii;;:ed~.-----:p""rI""o""r i""nv-:-est=lgat=io""n~ad7d~re~sse=s-::p~ro'blem: -SoeFilo# .' Private problem -NDAP will nor consider because: -_' _ Water originates onslte and/or on neighboring parcel I -location Is ou:tslde SWM Servloe AraB. DAlE CLOSED; .4.J.2:'1d..:J5:. by: m.. I)lfM • c.... _ Other (Specify): ·1-----·----.. _--------_._--_._......:_-_._-----_._-- '--------------------------- NOV. 8.2004 10:33AM I· . . -.-.. --~ ............. KC WLRD , ' I KING COUNTY SURFACE WA~R MANAGEMENT DIVISION DRAINAGE INVESTIGA.TION'REPORT Page 2: FIELD INVESTIGATION LLAINT #!l4-1000'MBTZGER tes!igated 1-6-9S by Doug Dobkins with Mrs. Metzger omdteto cUscuss her drainage concerns thatfloodcd the baFelnent afher house, NO. 339 P.S/20 'IIIe basemeDt was fiooded and damaged tbIee rooms and a bathroom, Mel2gcr 1Ives below road grade and recieves water froIIl1481h ave Eaad also a ditch to the north afherproperty that Is aIJIIed right at her Iiouse. She has a SIIlIIII yard cIIaIn in the noxtcast comer other lot tries to handle this flowlt IlJlpeatS the SIIlIIII yard cIraIn couIdn't handle the llow ofwatcr and overtopped'and flooded the basement. roadside ditch hu waJet COIItribtIIed by 1hn!e pzoperties to the north ofMelzgtr that dtains into this d(tch. Mrs. ~ger wants to know who is rcspoDSible for this dtainage and who can 1Ix the problen1, 1 ' ." 1 1 1 ketc:h~: --r-,-----,------~~~~~ 1 I 1 1 1--"'''' """ - . .. " Pat9,==_"". "'" .... ::: .. ":: .... ::':. ==._ ...... _ .. ______ . • .' NOV: 8.2004 10:33AM KC WLRD s--_. I·· . I ',,' , .. I' -1·. I I- NDAP l'R:IOlll'rY SCORXNG" kiWi Me..+.z~e.,.. Project NWllber~ ,,' . "'.*"'***"'*.·~*·"''''*******.***'''J:MPAC'l' CllJ:TERIA****.*******.*******"'***t1:*" POINTS-ADO Q,2 Ii!PBQEERT~;SS FUT. BISK #MPACT OR 4 FOB sEVERITX ;!;MPa.~iD (+0,2 OR 4) ., .. Livinq structur~, -I-finished· floor . (20 + ..J2...) X + .J:L co AcceSS (8 + -) X + -'" f.) septic/Well (8 + . ) X + .. 0 - -Other struoture or (4 + -) X T .. ~ 0 crawlspace ~ -.0.... . ;2 Landscapinq/yard/· (1· + .JL.) X +. 50 parlcing otber property/ (.5 + ...1L) X J:L. + JL = 0-dr.ainaqe system 0 Natural resource 3 + .. + '" I. I I I I I . ."'************.******EVENT FREQUENCY FACTOR*",* •• *******.",********** I I I Chronio (1+ times/year) ••••• 20 2-5 years; indefinite but . o.ften; channel erosion •••• 10 E.!'.!'. = . 10 SUBTOTAL X E. F. F. 50 .1t2~ 5-10 years ••••••••••••••.•.• 5 ADD 20 POINTS IF IN 0 10-25 years.................. 2 A TARGETED :BAsIN + yff AM >25 years................... 1 TOTAL IMPACT SCORE =~.,/#.~~~~!iJ-- Date: 31111 /¥S: Rated by A C'M . I .,. ,. *********.********"'*******COST-SENEFIT RATIO"'.**"' •• "'*"'''·.'''''***'''*·'''**· .. 'COST OF ~OLUTION = $ J~ 2.)1) "". '1'1'1 AM TOTAL IMPACT SCORE X laO/COST = N'DAl' PluoRXorY SCORE == I. 16 Date: * Note: < 10 years receives I V ,e:5. I ··-:~-· _. . .... .:.... .. : ---. --------------.-.------ I r------___________ ·•O ;,;.=. ",.O="" .. c;. =-.~----• ..• . . __ ... __ ._ ..:.:;:--;:-.= ;=7'·~O' .. =.~,=-~._." .. ".0. __ •.• 0 ..... _ ... _ .. I I I I I I I I I I I I I I I I .:>.:>t~·"'; ___ KC 7~"~~;"+--+ -~""I--r-i~-...j..,rl-.-' I 3""" P.7~0 i' r---~"'>7,~+-"><: -:'~'--"I"'~ . , DATlih 3-15-95 '\" ' TO: llANDl" 8NOW FROM. JIl.AN. MEYERS BE. NDAP Bw.tn\,UON 1011. COHPLAIN'l NO. 94-1000 pM HE'l:iGER BAPKGRO!!NJ) ; The o~iginal complaint was called in on 12-29-94 and Doug D. completed the initial field investigation on 1-6-95. Randy Snow and I spoke to both Kss. Kstzge~ and 8c~oede~ during ou~ field evaluation ~n 3-6-95 on surface water from streets, pastures and yards nortb and east of Metzger·s property which accumulate and flow into a ve~ n~row drainage ditch within the 14Bth Avenue 8E R/W flowing south along the west eide of 148th into the NE corner of Metzger's yard whicb is a low point below . road g~ade in this neighborhood basin. The flow partially drains into a private OB at the NB corner of har yard which conveys same water through an 8 inch buried CPP pipe west aropnd the no~ side of her hoQse and diScharges west into the Schroeder-'s horsa pa"ture(see complaint 95- 00091 approximately 6 fset lower than Matzgs~'. back yard leval. A smal pdnd forms at the NE corner of Ketzger's yard and du~ing recent heavy runoff flooded into her basement filling several bedrooms and a bat~oom, damaging furni~e, oarpets and walls. The sohroedar's complaint includse reported e~oBion, sed~entation, and ~ncreased minor flooding aoros. the~ large sloping horee yard/paBture from NE to SW towards a low WOOded aJ:ea Which develope into the upper channel of Boney oreek which is tr:l.but~ of Hay Creek. For this report, the horae paature area impact a are considersd to impact a horse boarding commercial business. PINDING§! since the problem maets all. of the NDAP project criteria listed below, it ~alifiea for and has been investigated under the NDAP progrB$. • • • • The problem aite is within the SWN eervice area and does not involve a King county (Ke) code violation. The problem aite shows evidence of or reported localized flooding, eroeion and/o~ ssdimentation within the off road drainage system on private residential and/or oommercial property due to later upstream development (Property other than KO or State roads, parka or sohools). ~he problem is oaused by surface water (not groundwater) fr~ more than one adjOining property and creates impacts beyond the property owners' control. If there is only one affeoted property, that property contributes less than 75' of the proble.1ll runoff. ~hia project haa top priority rating under the NDAP beoauBe floo4iDg of living apaoe haa ooourred f~m a ato¥s judged to be le.a than a 10 year atorm even~. PAGE 10F 3 1----_. -----------------: -----------------------------'---.-------._----._----------___ c_ ------------- I~ I I I I I I I I I I I I I I I I I I NOV. 8.2004 10:34AM KC WLRD NO. 339 P.8/20 to till , OPTIONS AND DISCUSSIQN Op~ions consi~ered ~o convey ~he excess surface s~orm wa~er pas~ bo~h prope~ies include ~he following. "\ -1. Install an underground 12 inch storm drain system from the NE corner of the Ketzger's yard near the existing CB, west approxima~ely 130 lineal fee~ ~o jus~ inside ~he Schroeder's property line. Two Type 1 CBs woula be installed, one at each end of this 12 pipe. Prom the outllil~ of the second os to be located near ~he NE corner of ~1Ie Schroeder's horae yard on the south aide of the ca, a ScOUr protection rip rap outlet would convey the storm water safely into a grassed ea~han swale about 8 feet wide Which would run approximately 175 feet , south along ~e Sohroeder's east property line where it would discharge into an exieting ditoh line flowing east ~o wes~ down into wha~ appears ~o be a natural drainage channel which flows west-no~hwest, This storm wa~er swale would include a scour protection struc~ure/facility located a~ the outlet of the s~orm drain pipe in the SE corner of the horse yard in order to safelI'convey the peak flows from the end of the grasssd swale into the ex sting east-west man-made di~ch. , 2. This option is similar to No. 1 described above. The difference is that the conveyance facility from the NE corner of Metzger's yard west to the schroe~r's NE oorner would conaist of a grass lined swala in place of the 12 inch stcrm drain pipe. this opticn would include a U shaped discharge chute ~ade wi~ several rock gabion/aeno mattreasea eet on a layer of heavy duty filter fabric loca~ed at tha and of the swale a~ the west side of Me~zger's back yard. This chu~e would provide soil erosional protection where the storm runoff would discharge from the upper swale down into the swale to be located along the east side of the Schroeder's horse yard. From this point, the storm water would be conveyed south approximately 175 feet as daaa~ibed abova in Optiol1 No.1. :tMPAC!I) SCORE .. 220 popom SpLUTJON'1 Since the safe conveyance of the peak sto~ runOff through the Metl!:ger's yard is of primary importance, I re~OIIlIIIelld Option No. 1 be emplcyed to eafely convey the peak storm water flows past the Metzger's house. since a grassed swate migh~ erode or wash Out and fail resulting in another basement flooding ~ent, the storm drain facility included in 'option No.1 ia preferred basad cn reliability and safety. However, there is a question whether or not a Type 1 CS and 12 drain pipe would have the capaci~y to adequately protect the Metzger'. yard and homa. A small basin study was c~lated in order to verify the siza of storm drain facility required. The results of the study using the SBUH computer model ware as shown belOW: Basic Data Prom Haps and the Basin Area 25YR-24HR Precip. tc Soil Type Areas and eNs; XCSWK Design Manual. 3.6 AClres 3.5 Inches 24.0 Minutes Alderwocd Croup C pervious Area 75 iii of Area Area in acres ON ImperviOUS Area 25 2.7 0.9 86 98 PAGE 2 OP 3 ------.---. "'------,--"--------_.--------.---~-------------------,----------_.-------------.- NOV. 8.2004 10:34AM KC WLRD NO. 339 P.9/20 I' 71-----0---*--1 ( _ .. -._._ ...... _-_ .... I I 1 I I I I I I I 1 I I I 1 I RBSUL!I!S OF !I!JIB SBW ~OD BASI. AHl\I.YSIS FOR 25 YEAR S!I!ORM: ... ~ ,. pBJUt Q CPS !I!-'BJUt ImS VOlomm CF 1.70 7.83 31,065. Based on a design peak flow of 1.1 CFS, a 12 inch concrete storm drain pipe at a 2\ slope would have an ample capacity of 5.5 C!'S. However, sinoe tbtll maxin\UIII capacity of a norma:r Type 1 C8 grate inlet equals only about 1 CFS, an expanded grate or oone typs rebar inlet structure would be required along with a below grade rim inlet set in a depression as well as a raised masonry type semi-oirole wing wall around the CD inlet to help confina and diract: th .. peak flows down into ths OR inlet. A grassed earthen emergenoy overflow swal.. woqld also be required to convsy peak flows exoeeding the design peak flow of 1.1 OFS around the house. This projeot is estimated to oost approxin\ately $ 11,200. The feasibility of this projsct includes the following limitationB' 1. The clearanoe on the north side of the Metzger's house is tight and will probably slow construotion work along the north property line. Aocess to the backyard will require temporarily removing a portion of a 4 foot high fence in two locations for equipment and installation of the storm drain along the north property line. 2. Utility conflicts along the north property line are unknown except the exieting Ii or B inch CPP drain pipe shown on tbe fiald investigation report. Other utilities could be in the YAre Area.? 3. the hOrse IIenBitiva owners as Construotion in both y~dB may be limited by poor aoils and yard operations inol~ding breeding/foaling ,season or other ho~aa iSBuea. The project must be ooordinated with both required 'RIOIUTY SCOlU!: .. 1.96 PAGB 3 OP 3 NO. 339 P. H!V20 NOV. 8.2004 10' 34AM "(~K~Cr1WLmR~D~~=::~-::;;=-;,~~;:;;;;;;;; _____ '-__ I MANAGEMENT DIVISION nBAlNAGE INVESTIGATION REPORT ~2; FIELD INVEST1GATIO~ . ': I COMPLAlNT #9S'()o09 schroeder Investigated 1-9-95 by Doug Dobkins Meet with Mrs. Mttzger onsl!e to discuss her drnlnage COncerns that flooded the basement 'of her house. _ _ . I Tho basement was flooded and. daml\ged tIu-eo rooms 8l\d a. bathtoom. ~ lives below l'OIId gI8de and recleves water from 14Sth ava SE and also a dlteh \0 the north Ilfher property thsr is ainled right at her house. She has a small yard cIrai!Iln thellortea.st corner other lot that tries to handle this :Ilow.It appeals the &mall yard cIrai!I couldn't handle the 110w of water IIDd overtopped and ll00ded the ba!iemant. I Tbi8 roaIIsido dlteh has water contributed by Wee propcrtles to the north of~et that drains inlD this ditch. Mrs. Metzger WBllts to kilo, who Is responsible tor this draiIIage and who can fix the probllllll. Tbls also affecting the down stream I14ighbor IlfMe~er. l!JJynIond Schroeder. COlllp1llint Dumber 9S~009. I oalIcd Mr. _Schroeder IUId explained that this would be looked at under the NDA review 00 I Me~er complaint and we ~ose his tile to Metzger. ~ ~ I ~ ~ -,~ T'" I ~:~ l h; -~61 I ..... - -.. ,- Investigated bY;;~~;;~~~~==::J __ D::at.~:e_~===~ _____________ _ ----~ NOV. 8.2004 10:35AM KC WLRD NO. 339 P.ll/20 KING COUNlY SURFACE WATER MANMIEMENT DIVISION ~. DRAINAGE INVeSTIGATION REPORT iype ~ ., :~le_.~o:.95~~ (Cay) (I!o..'~)""'" Page 1; INVESTlGA1l0N'REQUEST Received by: f J.. Date: I/S 9$ OK'd by: RIJC(1ived from: (pl .... p~nt plainly ~ ocannlng). PHONE 2. 77-613?>-""'''-10(-NAME! schroeder, ADDRESS; 1~701 ,jE Ravhlt:>nd //tf7?1 ~ CIty A"e.Nmc/ State Zip~e-,- ~ location of problem, If different: !l8Ported Problem: Plat name: Lot No: Block No: cnheragenc~slnvotved: No Field Investigation Needed ~ Kroll 80S IE Th.Bros:~ ~ , Old 3~ I (0. Basin MItY Council DI:Jt 12.. Charge No: • "f'l-/OOO ___ ~ ~~ .....,It( ~ . t:.. O/SPosrr/ON: Turned to. ___ on ____ by __ _ Lead agenoy has been notlHed: --rr.:-=cr::;::-;::::::;::;:::::;==;------;:;-:=::-;;::;;;;;;;;;;;;;;;:;;:;-;;;:;:;::;:::-.. = Problem has been corrected. _ No problem has been identified. Prior investigation addresses";i;N., . -See File # . . "'ljet Private problem -NDAP wlll not consider because: -, -Water ol1glnates onslte and/or on neighboring parcel = Locetlon Is OU!Sld~ fN{M :::?:t7 _ Other (Specify): . . DATE CLOSED:.Q..lJ "Z--5/ts by: ---P{) ~ ---------.--.. -...... ---....... -.--.. -----... -.------._-.---. ~·5~-9-¢~/-d:dc(/----.----------· ---.. ---.... --.--.-- ,.---~~~~~~~~~~--~~~~--~---------- I' I J;' of InvestJgatlon: KING COUNlY SURFACE WATER MANAGEMENT DIVISION DRAINAGE lNVESTIGATION REPORT Page 2: FIELD INVESTIGATIO~ IoMPLAlNT 1195.0009 schrocclcr ~vestIgated 1-6·95 by Doug Dobldlls ------~~- P.12/20 L t with MrS. Metzger ollSite to ~ her draiDage concerns tIIat 1looded the basement Of~ house. ' , ,,", ~ basement was flooded 8Dd damaged tlUee rooms 8Dd a ba1lIroom. MelZger lives boIow road grade and recieves' water from 148ih ave BE and also a ditch to the north,ofher ~ that is aimed right at her house. She has a small yard drain in the norteast comer of her lot .. t tries to handle this f1ow.Jt appears the muill yard drain couldn't handle the 110'111' ofwater and owrtoppcd and flooded the basement' IfhIs roadside ditch has water QOIItributed by'thn:c properties to the north ofMdzger that drahls into t1Us cIItdl. MnI. Metzger wants to know who is responsible 1br this ~ and who can fix the problem. This also affecting the down sttesm neighbor ofMdzger, Raymond ~. complaint numbet 95.0009. I eaUedMr~Schrocdcr and'explelncd that this would be lookcdat under the NDA mtew on r~ complaint and we close his file to Metzger. ~ ~ I I I lse 116th ST I iOn'" - AVE 1.:~ __ ._._.'nY9~~_~_= __ ::-_=_= ___ = __ =-=_=_=_= __ :-_=:::-_=-::-_===-L~D~:at:9:::. ===-==-:--=-.== -: -----.:-:-..:--'--;-;.tiAliii ~~~"""''i<c WLR,N"O-- NO. 339 P.13/20 --I KING COUNiY SURFACE WATER MANAGeMENT DIVISION ·DRAINAGE INVESTIGATION REPORT, Page': INVESTIGATION 'REQUeST, Type c.. I 'Recelve~ bY:: '.7..f:..;_. _._~ ..... _., _.~~Bte:,. '.2~'B.~ <76' ' :OK'd b~~: ~_. Fil~ •• ~~;_ik:..~.l~ Received (10m: (Pl .... pri"' plainly for .... nninc). . (Day) I. :'~AME: Oa ve ::Jbbason ' . RHONE 25" S-Z08b' _ . __ _ (Ev., '. .' -rJ, . • :,ADORESS: ·//625 . ./l/g '/111& SE city.-Ren..ft,rz .. $tatG ' Zlpg;.OS -<;:;~~;~~:.; pr~~'~~ ~~i~~;en'~'''-~)5~'7'''~/l ' ,/iit9} /X;i· . J:{.;n . ~~A:~> .7351178S- , . '~'-, ----.::-----a'+-1161S> dew.; AtiE-.s:€~p~- I .. I I' I· , " ,f'un~ 'An? 1/4~,;' ·.aar/l~n /f/irhAv, /G ' P/dod'n.,5· -!-he' . JOfi/7$c!J'7 3-and . men Xu-5 . ,!?rIJp..jy, 7h~ (!u /ver-/ ¢In, It/·B+'· tl/J~ S~. j£,GPS -ro 13£ " . ~n/arp"', ' .. .. 1 . PI .. t :-.ar.\a: Lot No: ".' . Private plObJem • "'DAf' will nor consider beceuse; --. . __ Water originates onslle 'l-nd/or on neighboring parcel . . , •. ~,. " -:-Lo~llonl,s outside SWM" s1Jea. . . _ 0, thllr (SP, Berry): . O~I_C(;.OSEO.· '~ . .f~.9.1-'1.?, .. \:IY: ,.~i€-f='Dr-a1f']g'-"-~-"-'---'--------'-"': .. -I . KC WLRD • ·NO.339 I . P.14/20· .. . NOV. 8.2004 ,.10:.?~AM ,.j Z· .. ·1 I I I I I I I I· I I I I· I I I \ COMPLAINT 96.()185 JOHNSON, DAVE Investigated by Doug Dobkins on 2·21-96 •• 4 4; Mr. John~q,n was not present at the time of Investigation, I left a door hanger with card and phone #. Mr, Johnson 1& concerned about the runoff from 148th . avenue SE flooding his property anef the neighbor to the north of hi~ property MelZgers, There Is' a catchbasin at the northeast comer of SE 11 8th and 148th Ave SE which backed up during the stonn on February 8th, The pipe under 148th could not handle the capacity and backed up onto 148th anef ran to the west onto Johnson's property anef on Metzger's property, This problem looks to be created by the intense storm on February 8th, I will call Mr, Johnson to finef out whether the water backed up from the catchbasln or bypasseef the basin anef ran'down the driveway. NDA project'on the neighboring property of Metzger. Both live below road graefe. LEFT MESSAGE WITH DAVE JOHNSON ON 2·26-96 SE 116TH ST OPEN DITCH· 148TH AVE SE .. -----------"._-_. ------------,---,--,--_'" , .• .•.. -, .. _, ... ,._-_.--/_. ---------_ .... _ .. --.-.-' .. --'--'""' .... --_ ... _ .•. _--,. ,--~.-. NOV. 8.2004 10:36AM KC WLRD __ t NO. 339 P.15/20- " ' I K1NC!l COUN:rY(SURF~Cc WATER MANAGEMENT DIVISION DRAlNAGE INVESTIGATION REPORT ." , . 'Type G Page 1: INVESTIGATION'REQU,m I Re~ by: :r. L . , FileNo. q(o-55 '2- 9Cslved from: ' (PI ..... prtnt plainly for sca,,"lng). (Day) (e.<8) ItME: ta,ymo,.,d, 7j'o'Yi PHONE 2$!i-978S" ___ _ "DRESS: J 16/5 14871-. AVE SC' city Ren-ton , State Zip '98051 Elan of problem, If different eported Problem: , I, I' I I I l atnBm8: ther agencies Involved: iii rtJadwa..y, cla,/m. .... ' ", ,. . .... ~ . . ~' .. pJ!3"-10 '23 5..-Parcel No, /023 0.5 1'.3 ~ 3> 11/4 S·T R Basin 1'YIr.l( Counoll Diet lp, Charge No: '. " tjuJ-er 17??n-t , 6e. h' II 'n ~ c::t.. Lot No: Block No: No Field Investigation Needed ....-__ i Kroll 205 e... ThBros: Newlp2t, ;::r(1) , Old lP'2.'1 AlP ~5.D3) ~~ roMS£-C'rtlzen notified, on Ji2jq by hone _ letter _ in perso'n 1 ISPOSITION:, Turned toi ~n 31tf..~ by ~ _ Lead agency has been notified: , " ~ Problem, has been corrected. _ No problem has been identified. _ Prior Investigation addresses problem: Sae Fli. '" • ~ Prlltare problem -NOAP Will not consIder becausa: ' ,---.. " _ Water originates onsite and/or on nelghbor1ng parcel ' • _ Location Is outside SWM Servlclil Area. ~ other (Specify): ~ATECI..O~ED:...4.J~~ by:~ ~~""lklltjJ.-i -w*~~w..I.;II',J-1····-·· .. u •• • .• m , •• u n •••••••••.•••••• -••• --•••••.•. --.:-__ •• : ____ -'!:/!:r~~_'":..~-.-___ -~.~-~-;~ .. --.. --;-~-_ , . OR: No further action recommended because: I NOV. 8.2004 10:36AI'INa KC WLRD3' -~ ..... 6_ ... ~U .......... ~ Y J.U Y Q,\NO.339 I 1:.,.-··· ...... :··· "-:-'''' .u'l:lV'l ~~V~ ~3J.VM :JOV.:Il::lns AJ.NnOo ~NJ)f P.16/20· II I I I I I I I I I I I I Date: Mareh', 1996 Date of JinoatiaatioD: Man:!t' 6, 1996 RE: Evaluation for CompllllDt.: 96-0552 Tim Raym0n4 tLyunMeI2kcr 1161S 148th Avenue SB ReoIon. W A. 98059 DayP23S..!J7~ Ms. Metzker's homo lies belOw the road oIGvatIon of 148th SS. She slated that during the heavy minfaUs ofFebnwy. 1996, she exporIeocecl water iDsido the house. Two basement living rooms were damagml Tho carpets bad to be replaced IIDd the walls ze'painted. . Ms. McIzker said the water Is fIowhlg fi'om. SB' 1 16th Street., over tho property to the north and also down a cuIvert In the ftoIIt of tho propert1 to the north, The cuIvert water 1IOWB iIIto a CB In tho DOtIheast c:omcr other ~ and then 0IIIIlIlls next the tho 1IecIJwm wIDdows. This has happened at least once a year In the four yeaJlI she has owned the plOpcr\'f. She was IUIt _ ottho.water ptobIems when she bougbt tho home. .' . She fl:c:ls that water Is comhlg down the IIIrcct (l48dlj from. some MlOIIt development. I recommeD4 that this be tmnecl ovor the tho NDA Progmm for fIdher study. \~\l~1I.e, I , I 1'. I .,' i I ~~'. I . '. ~ I-=tJ :::===::;-~ I '. ,~-.--...... .. I __ --.:\~~:=.::~ ~~~::;E:'=--__ --__ ....... -.".----.-.--....,...--------i ----, t~ --.--.. -----.. --.----------------~--... -.. -~1--I 1----·· ----_ .. ------~~-. -~-.--.----,.~.~ ._-_ .. _---,--, ...... _- I I I I I I· I I I I I I I I I· I I I ---------. '4; ,,,", Date: March 26, 1996 JIM: Jeff Jacobson Neigbborhood DralDage Asilltallce Progt'alll COJIIpl8lllt EvaliJation Memo REllIlDAP Evaluation for Complaint f# 96-0552 Tim Raymond I Lynn Metzker U615148tb.AveDlIC SB . ReDIDD, WA 98059 Day P 235-9785 CompJaiat Chn!!oJ9U Original: Field Invest: FieldEval: Old Files: BIItkgro'UDd 2-23·96 3~-96 3-25-96: 4-02-96 !l4-1000,9S-0009 P.17/2a-..; Tim Raynioncl, the complainant, callecl Fe1mwy 23, 1996. The house sits S to 10 feet below the SUI1IIce of 148th Avenue SR. He-says runoft'ftom the roadway 120 feet to the DOrtb(SB 116th StIeet) is flooding IUs bascmet't. This road is not malntained by the coUDt;y. This has been a ro-o<x:urritIg pmbIem for bim ever sIIIce be bought the hOuse. Mr. Raymond Is the tim owner of the hOuse .. He claims this sort of flooding 0CC\I!8 four or five times a year. LynnMctzkm', tho C\U1'CIIt occupant ottbe bo\\se, had called in a compJaint Deoemberof1994. The investigation was turned into a NDA miew. The NDA review was given a top prlori1y 1ICQre. However, before any COIISIluction took place the owner of the house had iDslaIIe4 a catch basinlconwyancc IIYJ'I= ofbis own. The system IDsIaIled by the owner was very simIJar 1D the system .px:omineaded by the county. Thmcfore, the COUIII,y elected to QII1CC\ the: construction of the proposed NDA-funded conveyance systeJII. Findings l>uring nr.y site iIIvcsti8ation on April 3, 1996 I held a conversation with Mr. Gerspacb. Mr. Gcmpach is . the property ownu ablJttiDg Ms. MetzkerJMr. RJvm,ond 1D the north. He cJalms he cxperlenced some: mlnor tloodlng DB FcbruaJy 22, 1996. Apparently, some vandals had destroyed a iire hydrant on the Intcncotion of 148th Avenuo SB IUId SBl16th Street. The fire hydrant Is located 112 blOck upblll from the Metzker hoIIIe. Mr. Oerspach noted the Mc1zker bousehold eicperlencod damage of the 1iving spa"" in the basement due 1D this act ofvandalism. I called Ms. Penny Men:\I.I with KIng Counly Water/Sower PlS1rlCl No. 90 on April 3, 1996. She confumed an act ofvarulallsm had occurred involvillg fire hydrants on l"cbnwy 22, 1996. Additionally, she had a I;COOtdedcomplalntftom 11615 148thAvenue SB on this Dight -the night of the vandalism. II • I I I • I I • • I •• • • I I • ... _. 37AM KC WLRD NO. 339 P.18/20 TI!.js address is Ms. MeI2:ktrs'. Ms. Metzker placed ~ cqII to SWM on the fbllowiDg date: Fcbnwy 23, 1996 • This dnWIage. p1'~ does not qoalliY UDder the NDA Program criteria. The problem WlIS not par! of a 11atutal stol'mevent. The problem WlIS r:auscd by an isolated act af'\lllndalls m and not a storm evenL This was thefirstflooding comp~ ~ si.1lce the complaint logged In December of 1994. Mr. RayJDoIId did npgrqdc his stolm J:O.Dwyancc: iSYsteIJl since the original COIllplainL My couversation with Mr. Raymond 'WIIMan a sile lnvemigation, March 25, 1996 miled the cat&h buin system located on the northeastern poI'IiOD of the plOpeI'Iy was adequate for the water received. At that limo, Mr. RaymOnd's pri:maJy concern was the sheet flow comlng offtbe JlCighbor's property. This sheet tlow 'MIS obviously an isloatcd eveDt caused by the damaged fire hydranL Haviug noeIved no additional cmpplalnts for the last two lIIl\Ior storm IMmIS, NOVember, 199' and Fcbnwy 8. 1996, respectively, SWM considers the file closed. '.. . .•.. ---. .'. . KINGCOUNTYWATER~RESOURCESDIVISION _ .• J;:'.,j ~NOV. 8.2004 10:37RM---KC WLRD . NO.339 P.19/S0\ 5 . 'DRAINAGE INvESTIGATION REpORT ' ~ Page 1: lNVl!SnGAIlONRBQUBST Type _..,-, _ 1 PROBLEM:. [ytl1!'lVt1& RECBivxoBY: NW'f QK'dby:~ 1i'ILENo. gq-OI'5"( 1 Received from: NAME: ~~ RlAkl1iMe.- (Day) (~) PHoNE 254: -2g28 (Eve) ( ) 1 . ADD»'Ss:\UVZA-[4.-Z/" I<II~ BE City: @Tl?N S~tei......-_ Zip q8® 1 1 1 1 ~cation of problem, if different: 1 Plat name: . Lot No: Block No; Other agencies invnlve<!' 1 No field investigation J"eq1lirC(I-::-:~ II -----,-.~ I '~I;lr "-l'.J,_II~~~,,,;n .";," "" =~.:::..I~\..._. , . If) ~..LJ....... 1 ~ 'S .. T R ParcelNo. !Oz..'Ol>'5 -4.e"'lz. KroU8'lI5'e ThBros: New !.p2.{p:If] • Old ':35 '04-, I · B~ • WiN Coun~DistriQt& ' . Cbarge No .. ____ --- REsPONSE: ~icitijiedon shieff by; ~ phone letter ._inperson 1 p'l... -rfi"l; ""1~;~'" .;-}t4r sl!"~ ·(p~Ut-O /11 Nb A-t:i~h~ / t:',,1'1 (r ;-0 t.Aj~,e/\ ':A £.s7.1f 8 t::."-f /T ,i);r~.I"'/.A-"~ CdV~ .+1AJ D 6-4-Y~ H f"/l . ~ ~ V'MAS'1kL. '1 DISl'OSlTION: Turned to _ on I I by_ OR: No further action recommended because: 1 -Le8d agency has h~ Tlotifi!!d:_ \ . ~ Problem has been corrected. __ . No pl'Oblcm has been identl1ied. _ Prior Investigation addresses problem: . 'SZl:b.I# ' I _Private problein -N.OAP will not consider because: __ WlUer originates onsite and/or on neighboring parcel. Location is outside WLRD S~ _Other (Specify): , 1 DATE CLOSED: "3/ / I 'f'., By: =t£:L ", , . /""fO?~t/(~.rb. ______________ _ 1"---'-'" ... -.... .. ... . -. -... --.... --. ------.. -----------------.. --.. ----------.- I I I I I I I I I I I I I I .---- Complalnt 99-01 S lllut1edge Investigated by Pat Slmmona 03/01199 I met with MS. Rntlcdge about the drainage that flows In the Horse pasture behind her home. The water flows out of a pondlwetland and lhrough a swille that is about SO feet from her SOUIh fence. Tho water is about 2 feet wide on the West edge of her property and S-6 feet wide on the East side ofdle.pan:el. 'This appears to be a na1.1D'al dralnage course that flows wh8ll1he wetland/pond get twl 8IlOugh. She would like to keep the ~a\ll narrow to allow mote room for the horses. I stated that I would look into l!1e nature of this drainage to see how it is protected under CIIlTeIlt codes and provl". her with some information on the l'eStrictiODS nelR' the drainage. 142nd Ave SE r D PondiWetland 11642 Rutledge Pasture Dlainage SWa1e NTS --------.--.-...:.... .. _. -----------.---.~-----------_._" ---------- I I I I I I I I I I I I I I I I I I I CAMWEST-EAST RENTON LEVEL 1 DOWNSTREAM ANALYSIS KING COUNTY, WASHINGTON Date: 9/19102 Revision Date(s) 11110/04 Prepared By: Geoff E. Tamb1e, PE Tyson Wentz Reviewed By: Job # 01-047 Rebecca S. Cushman, PE I I , I I I I I I I I I I I I I I I I I Prepared By: CAMWEST -EAST RENTON Levell Downstream Analysis King County, Washington Prepared For: CamWest Real Estate Development, Inc. Issued September 19,2002 Revised November 10,2004 GeoffE. Tamble, PE Tyson Wentz Reviewed By: Rebecca Cushman, PE I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS PROJECT OVERVIEW .............................................................................................................................. 3 GENERAL DESCRlPTION OF PROPOSAL ........................................................................................................ 4 PREDEVELOPED CONDITION OF SITE ........................................................................................................... 4 DEVELOPED CONDITION OF SiTE ................................................................................................................. 4 OFFSITE STORMWATER RUNOFF ................................................................................................................. 5 DRAINAGE BASIN, SUBBASINS AND SITE CHARACTERlSTICS ....................................................................... 5 OFF-SITE ANAL YSIS ................................................................................................................................. 6 STUDY AREA .............................................................................................................................................. 6 TASK \, STUDY AREA DEFINITION AND MAPS ............................................................................................ 6 Onsite Basin ..... . .......................................... 6 Upstream Basin ................................................................... . ................................................. 6 TASK 2, RESOURCE REVIEW ....................................................................................................................... 7 TASK 3, FIELD INSPECTION ......................................................................................................................... 7 TASK 4, DRAINAGE SYSTEM AND PROBLEM DESCRlPTION ......................................................................... 8 TASK 5, MITIGATION OF EXISTING AND POTENTIAL PROBLEMS .................................................................. 8 APPENDIX .................................................................................................................................................... 9 Preliminary Plat Map Existing Conditions Exhibit Developed Conditions Exhibit Soils Map Soils Legend Table 3.2.2B .. Equivalence between SCS Soil Types and KCRTS Soil Types King County Drainage Basins (Figure 2) Study Area Maps (1990 King County Sensitive Areas Map Folio) Wetlands Streams and 100-Year Floodplains Erosion Hazard Areas Landslide Hazard Areas Seismic Hazard Areas Coal Mine Hazard Areas King County iMAP Drainage Complaints Maps Drainage Complaint List and Complaints Downstream Drainage Exhibit King County Off-Site Analysis Drainage Table TRIAD ASSOCIATES-LEVEL I REPORT FOR CAMWES1; EAST RENTON PAGE 2 I I I I I I I I I I I I I I I I I I I PROJECT OVERVIEW This section gives an overvIeW of the project site in both the pre-developed and developed condition. There is also a description of the runoff characteristic of the property and the existing soil classification. The proposed project consists of a Single Family Residential Development for 66-lots on 15.92 acres in an R-6 zone. The site consists of two existing lots that total approximately 19.6± acres, with approximately 8.2± acres of sensitive areas to remain undeveloped that include a wetland (please reference Preliminary Plat Exhibit in Appendix). The project is generally located west of the intersection of 148 th Ave SE and SE 120 th st. in King County; Section 10, Township 23 north, Range 5 east, W.M., Washington State. I -/~ Vicinity Map NOT TO SCALE PARK & RIDE TRiAD ASSOCiATES -LEVEL I REPORT FOR CAMWEST, EAST RENTON PAGE3 I I I I I I I I I I I I I I I I I I I GENERAL DESCRIPTION OF PROPOSAL In general, this project will replace one existing single-family home, a shop, a small covered storage building, and a gravel driveway with 66 single-family lots. Part of the major site improvements will include the installation of neighborhood access streets (sub- collector, sub access, and minor access). l48 th Ave SE will be improved with full half street improvements as required by the King County conditions of approval (To be determined). All runoff from the site and the frontage improvements will be collected in the proposed conveyance system. Detention and water quality will be provided according to King County Standards. Two drainage facilities are proposed, one for each drainage basin. A vault is proposed to be located in the northwest comer of the site and a pond at the northeast comer of the proposed project of Rosemonte, adjacent to the north of E. Renton. The dimensions of the proposed lots and roadways will require buffer averaging on the western portion of the site. PREDEVELOPED CONDITION OF SITE The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blackberries, and trees (See the "Existing Conditions Exhibit" located in the Appendix). The site has two drainage basins, one that generally drains towards the northwest and the other that drains to the west. A wetland occupies the western portion of the site where the two basins combine then flows to the north through Honey Dew (Honey) Creek. Overall, the site slopes from east to west at approximately 5-15%. The site generally slopes from 148 th Ave SE down to the west towards Honey Dew Creek. DEVELOPED CONDITION OF SITE The developed site improvements will be located on the eastern 15.92 acres of the property (See the Developed Conditions Exhibit located in the Appendix). The preliminary plan shows 66 single-family lots with subcollector, sub-access and minor access roadway improvements. l48 th Ave SE will be improved with full half street improvements as required by the King County conditions of approval (To be determined). The detention/water quality facilities will be designed to meet the Level 1 Detention TRIAD ASSOCIATES -LEVEL I REPORT FOR CAMWEST, EAST RENTON PAGE 4 ,. • I • I I I • I I I I I I I I I I I Standards and the Basic Water Quality Menu from the 1998 King County Surface Water Design Manual. OFFSITE STORMWATER RUNOFF Flows entering the site from the east come from the west half of 148 th Ave SE. Runoff entering the site from the west and south adjacent to the wetland is collected in the wetland area. The wetland area will remain undeveloped. Runoff generally does not enter the site along the north and south property lines near the proposed lots since the site slopes from east to west. DRAINAGE BASIN, SUBBASINS AND SITE CHARACTERISTICS The existing site has two drainage basins that drain into Honey Dew (Honey) Creek which, according to the December 1990 King County Sensitive Areas Map Folio, is an unclassified stream in the May Creek Sub-Basin. Honey Dew Creek combines with May Creek over two miles downstream (north) of the site. May Creek is in the Cedar River Drainage basin and ultimately discharges into Lake Washington. The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blackberries, and trees. Most of the trees are located in the western halfofthe site with the pasture area occupying the eastern portion. The blackberries are located throughout the property. According to the King County Soil Survey, refer to the Soils Map and Legend in the Appendix. The site is underlain with AgC (Alderwood gravelly sandy loam, 0 to 6 percent slopes) and AgB (Alderwood gravelly sandy loam, 6 to 15 percent slopes) soils belonging to the S.C.S. type 'c' hydrologic group or 'Till Soils'. Onsite topography is mild to moderate, sloping to the west at approximately 5% to 15%. Note: The 1990 King County Wetland Inventory did not list the wetland on this property. The 1987 Basin Reconnaissance Program did not list Honey Dew (Honey) Creek in any of its basin reconnaissance data. TRIAD ASSOCIATES -LEVEL I REPORT FOR CAM WEST, EAST RENTON I'AGE 5 I I I I I I I I I I I I I I I I I I I OFF-SITE ANALYSIS This section outlines the drainage basin, within which this project is located, highlighting the downstream conditions one mile from the project site. STUDY AREA TASK 1, STUDY AREA DEFINITION AND MAPS This site is located within the May Creek Sub-Basin of the Cedar River Basin. Onsite Basin The site contains an existing house, a shop, a small covered storage building, and a gravel driveway. The remainder of the site is covered with a mixture of pasture, blacklierries, and trees. Most of the trees are located in the western half of the site with the pasture area occupying the eastern portion. The blackberries are located throughout the property. According to the King County Soil Survey, refer to the Soils Map and Legend in the Appendix. The site is underlain with AgC (Alderwood gravelly sandy loam, 0 to 6 percent slopes) and AgB (Alderwood gravelly sandy loam, 6 to IS percent slopes) soils belonging to the S.C.S. type 'C' hydrologic group or 'Till Soils'. Onsite topography is mild to moderate, sloping to the west at approximately 5% to 15%. Upstream Basin Approximately half of 148 th Ave SE along the entire site frontage currently sheet flows into the site. Flows from the frontage improvements will be collected and conveyed to the proposed detention/water quality facility. The area where flows enter the site from the south and west adjacent to the wetland will remain undeveloped. TRIAD ASSOCIATES -LEVEL I DOWNSTREAM ANALYSIS FOR CAMWEST, EAST RENTON PAGE6 I I I I I I I I I I I I I I I I I I I TASK 2, RESOURCE REVIEW "1998 King County Surface Water Design Manual" "1990 King County Sensitive Areas Map Folio" "1973 King County Soil Survey" There are no apparent problems associated with this project. TASK 3, FIELD INSPECTION "Triad Associates" preformed a field visit on 4/03/01 to locate any potential problems upstream or downstream of the proposed development. The weather was overcast and approximately 55 degrees with small amounts of runoff in the drainage systems from the previous day's rainfall. See the "Downstream Drainage Exhibit and Table" located in the appendix for a complete definition of the Study Area. Drainage leaving this property is collected in an existing wetland (A) and conveyed off site to the north through two 12" CMP culverts (B I & B2). The onsite wetland has a slight ridge separating the wetland on the north property line of the site. The runoff that leaves the through the two 12" CMP culverts combines in a drainage ditch adjacent to the north property line (C). Drainage also leaves the site on the north east side (C2) then drains west and intersects with the drainage from Cl. From here the runoff flows to the north through a natural drainage course called Honey Dew (Honey) Creek (D) for about 500' before entering a 24" CMP private driveway culvert (E). The property owner adjacent to the culvert stated that it has only flooded once, around 15-years ago, when a neighbor downstream of their property dammed up the creek to make a waterfall. The waterfall has been removed and the culvert has not flooded since that time. From this culvert, the natural drainage course continues to the north in a well-defined channel with heavy ground cover (F). The final observation of the downstream investigation was approximately 2000' downstream of the site (G). No evidence of flooding or major erosion was observed along the downstream drainage course during the site visit. From the last observed point in Honey Dew (Honey) Creek (G), runoff continues north then west before combining with May Creek and eventually reaching Lake Washington about 6 miles to the West. TRIAD ASSOCIATES -LEVEL I DOWNSTREAM ANALYSIS FOR CAMWEST, EAST RENTON "AGE 7 I I I I I I I I I I I I I I I I I I I ---------------, TASK 4, DRAINAGE SYSTEM AND PROBLEM DESCRIPTION "King County Water and Land Resources (WLR) Division Drainage Complaints" King County suggests not following up on any complaints before 1990 due to their age and development that has occurred. Complaints Nos. 94-1000, 95-009, 96-0185 and 96-552 all pertain to one parcel (9353). The majority of the complaints pertain mostly with drainage runoff from 148th Ave SE. In particular, an existing ditch was discharging into this property and flooding the basement. King County performed a study of the situation under the Neighborhood Drainage Assistance Program (NDAP) and recommended the installation of a catch basin with a 12" conveyance system to direct the flows away from the home. This project was not completed by the County; however, the home owner installed a similar pipe system as recommended by the County prior to February of 1996. Therefore, the NDAP study was cancelled. Complaint #96-0552 was due to a broken fire hydrant (vandalism), not stormwater, and therefore closed. Additional complaints are within the I mile radius of the project site but are not in the downstream drainage path. The complaints are linked to a private home drainage system and a private road washout due to no drainage system rather than flooding, or erosion of the large drainage course that the site will discharge to. TASK 5, MITIGATION OF EXISTING AND POTENTIAL PROBLEMS The developed site runoff will be detained to the Levell standard as outlined in the King County Surface Water Design Manual -1998. The KCRTS Levell detention standard requires maintaining the high flows at their pre-development levels for all flows greater than the 2-year peak flow up to the 10-year peak flow. The site is proposing to utilize two detention systems. The detention facility release rates will be based on the existing runoff from the area of the site that is being developed. The wetland area and associated buffers will remain undeveloped. One half of 14Sth AVE SE frontage will be picked up in the conveyance system along the site frontage reducing flooding discussed in the drainage complaints. TRIAD ASSOCIATES -LEVEL I DOWNSTREAM ANALYSIS FOR CAMWEST, EAST RENTON PAGES ' ..... , NOJ{)NIH$Y..t1 'AJNII03 {)NIJI Ig ij~ ~~ "-I ; Hi I AJII3dOlld NtfWIIIH:JS/1I3,JO>l37JNI i---l l e ~ ~ . r: 3" C) NO.J.N311 .J.SV3 ~:?~~~~! .g ~ ... :1 C) I JN3Wd0731130 JS3MWtf:J "-It':; •••••• ~ r "I~ Ii ~\ I ~" I I:; • ._,.....,_--~: I~ :0 1 I • il ". n. -_.-=;;;';'::~I ,; """""e,_ .... i i II ~a " ~. J tf7d AlltfNIWJ7311d "g IIOJSIYII lift 1111 ~ :i ~ iii I II) I iii ! CJ '" J i I .., '" ~ ... ~ 15' ~~ <0 ~u Ole i I r------····r· .... ii'" '1 I ~~~ , I'i ~~I I : ~~ I ! s~' I .~! I ~i~ I I~~. I I J I •• ~ • ~ I • !II!! II ! I!IIIIIIII! Iii 111111111 ij I I I I I tsl'; ~ i~~' I ~~! § N -j '~, 0 ~~, r --~~'I ~ ~ .. I I I~~ ~ ~!~ I I ~ ~ " II il h !!;I! i i~ QJli ~~~g~ ! :j I~h Ilm§ ~ 5 ~~~! ~ in~ i Ii wli§~ Ui~~1 , w' no, ~~ i ~;~Ii 1~I~i~ '3£~ ~ i ~~. 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' .::Ul'.JaMasdoJd - - - N01DNIHSIIM '/.lfi/Jo:J DNI)J "-~ ... .... <:) ~ h .,!. .... .~ <:) ~~ ~§ g ~ g ~ § .LStl3 .LSElMWtl:J .ll81HX3 SNOI.lIONO:J ~NI.lSIX3 IJ .. t2 ,.,. « G '" Vl Vl "1' 6 « "' T '" g N Q , I 0 ;;: . ... . -, ........ . , .. " ..................... . ... -'-... , ....... .. ~., .................... . 'Lsq-dLtOL leoo.ox LtOLO --- ,,, 'L1 no,(D1 'OMp·J.Aoo.r LX3L to L \lonld.ouD:>\ S.I!JOMa\L to LO\Sl:>3rO~d\ :3 _ _ _ _ _LZ:_tO~ AO_IU.~ ... '.:< :~';'. )< - - 6"" 0 N 0 0 --II = --~ W ...J <C ijl () (/) 0 , , ..... -.;;:;.::~::.' ... -.. -- N019NIHSlfM 'ilNnoa 9NI>I .1N3H .1Stl3 .1S3MIIVtlQ P} "/o,/.Jao - 1181HX3 SNOl1l0NOa 03d013A30 'lsq-daOI 'L IXII Ino,(o7 'oMP'ldnaOI \,fJOU!W!/aJd\ sa/lJoMO\aOIO \SJ:JJrmJd\ .'] _ _ _ _ _ _0.'-.O~ A~IU"_ -- "i ':1'1 o • - - (() OJ .... <: U o Vl Vl f o <: 5' I- ~ o o N i;j) , i GARRY STRUTHERS ASSOCIATES, INC. Date: . To: August 8, 2001 Bruce Whittaker King County DDES From: Gary A. Norris, P.E. Subject: Road Improvements Cam West Plat 3150 Richards Road, Suite 100 Bellevue, W A 98005-4446 (425) 519-0300 (phone) (425) 519-0309 (fax) Project Name: East RentoniIntelkofer- Shirman Property Project No.: __ P: ___ T: __ _ CamWest is proposing the development of a 68 unit single-family plat on 19.57 acres located at 12013 148th AvenueSE. The plat will have approximately 650 feet of frontage on 148 th Avenue SE. 148 th Avenue SE is a two-lane arterial with a 6-8 foot shoulder on the west side and a 3-5 foot shoulder on the east side. The roadway maintains a continually increasing downgrade from the south property line of the proposed plat to the north property line. The percent grade at the south property line is 2.4% whereas at the north property line it is 4.6 %. "'NDrlli.oUliufclrtli.pIoperl:} line, the percent grade increases dramatically to 9 percent with a grade break 50 to 75 feet north of the site. This change,in;grade;.create,;,a;potential;sul?§taIlc!ard;s(oppihg,sig!jnlistance;(SSD)! condition according to the King County Road Standards (KCRS, 1993) .fOl':SOlltllhQulld=v.ehic!es'On l.4lL.<!!..&venne,SE,approaQjJing-the-site .. Need for Road Improvements or Variance for Stopping Sight Distance This memorandum responds to King County's preliminary request for CamWest Development to reconstruct 148 th Avenue SE along the plat frontage and to the north of the proposed plat, or obtain a variance to meet KCRS for stopping liight distance. This issue was first raised in 1999 with , .. Harbour Homes, the previous project applicant forthe property, and was raised again in a meeting between the CamWest Development Design Team and King County staff on Thursday April 19, 2001. . , CamWest believes there is a question of whether there is an actual sight distance problem under the King County Road Standards. A substandard SSD condition arises under the KCRS because of an administrative decision to use a design speed of 10 miles per hour (mph) over the posted limit, although this definition of design speed is not specified by the KCRS: Utilizing a 40 mph design speed (the 85-percentile speed on 148 th Avenue SE based upon a recent speed study) results in an acceptab Ie SS D. <!!tssnming-l.~-is·apPJQPti!\\~to'J1Stl~~;:I'l}l!h,designcsPeed"Jhe;sljpst.andard:SSl;l c..conditi on-i§:Rreexi~t\ng'allc!'.lJnrelat:~t:!:to;thecimpacts'ohhe:pr.QR2sed:p\at. Reconstructing 148"' Avenue SE to meet SSD would be extremely burdensome and cost prohibitive. The KCRS provide that the extent of frontage and off-site improvements must be tied to the impacts of the proposed development, as required by Washington law. The proposed plat did not create and will not exacerbate the SSD condition on its frontage road. Additionally, there are no known safety issues associated with the present grade. Therefore, any requirement to regrade this roadway to improve the SSD would not be consistent with the KCRS and Washington law. -e:\2001 projects\01-002.04 east renton\camwesteast renton final g. norris merno.doc 10/15/01 0) '. " \. '( Memorandum October 15, 200 I Page 2 Because requiring these improvements would exceed the County's authority, a variance is unnecessary. Existing Stopping and Entering Sight Distance Conditions Garry Struthers Associates (GSA) performed a field study of stopping and entering sight distance on April 18,2001. The proposed access to the plat at that time was approximately 120 feet south of the north property line. The SSD at that access point and its intersection with 148'h Avenue SE was observed to be 318 feet for southbound vehicles and 425+ feet for northbound vehicles. The posted speed limit on 148'h Avenue SE is 35 mph. The KCRS does not stipulate the design speed to be used to calculate SSD .. King County has administratively chosen to use posted speed . plus 10 mph for design speed, Based upon a 45 mph design speed, SSD of 425 feet would be required for northbound vehicles and 400 feet for southbound vehicles under the KCRS. (The increase of 25 feet in the SSD for the northbound direction is the result of a correction for downgrade specified in KCRS 2.12. The KCRS does not identify an adjustment to reduce SSD for the upgrade condition.! Adding 10 mph to the posted speed to calculate design speed increases the required SSD by 150 feet over what would·be required for a 35mph design speed. If a 35 mph design speed is used then the required SSD per the KCRS is 250 feet in the southbound direction and 265 feet in the northbound direction. It should also be noted that the KCRS adopted the highest value stopping distance for a 45 mph design speed of 400 feet, established by AASHTO. AASHTO is the agency that establishes national standards, including SSD, upon which the KCRS is based. According to AASHTO, the assumed speed for a 45 mph design speed ranges between 40 and 45 mph, with a calculated SSD ranging from 325 feet to 400 feet. Based on a recent speed study on 148'h Avenue SE in the vicinity of the proposed plat, the 85- perc~ntile speed is 40 mph? The computed SSD for 40 mph is 318.7 feet and 325 feet when rounded for design, This suggests that a SSD of 325 feet wouldbe adequate in this section of 148'h Avenue SE. There is currently 318 feet of SSD available 100 feet south of the north property line that increases heading south as the percent grade decreases. Additionally, the KCRS, unlike AASHTO, does not adjust the required SSD to reflect the reduced stopping distance required for the upgrade condition (southbound approach to the plat). Since the SSD deficiency on 1.48'h Avenue is a result of the vertical curve to the north of the site with a downgrade to the north of approximately 10 percent the average running speed should be used in the SSD calculation for southbound vehicles. According to the recent speed study, the average ' mnning speed is 33.7 mph. This results in a SSD of 212 feet. Therefore, lipplying,the;upgrade (£.Qcrec.tiQ!J:l2.er-A:ASHTe~an:alysis;procednres;to:this;situation;nollllts;in;fI1ore:than;snfficient;SSD;at Cbe,originally-proposed:si.te-access'intersection:and;acro'Ss;tnMemmnoer:of:llie-plat,to.tlie,soutIf. Adequate SSD may also exist to the north property line but has not been validated by field observation. ! According to the American Association of State Highway and Transportation Officials (AASHTO) Green Book (1984), page 143, "Design Speed is used in calculating downgrade corrections, average running speed in calculating upgrade corrections." 2 The speed study was taken from 12:00 AM Tuesday May 7 to 12:00 AM Wednesday May 8, 2001. The counters were stationed 50 to 75 feet north of the north property line. e;\2001 projects\01·002.04 east renton\camwestea.st renton final g. norris memo.doc 10/15/01 U) ------------~---~------ '. • • • " Memorandum October 15,2001 Page 3 An analysis of the entering sight distance (ESD) at the initially proposed access indicated that the project would not meet the KCRS required entering sight distance (ESD) for vehicles approaching from the north (the critical ESD movement), In the field study of sight distance discussed above, 390 feet of ESD was observed at the site access compared to the KCRS requirement of ~ " Scope of Improvements Needed to Achieve SSD Based upon 4Smph Design Speed Changing the grade of SE 148'h Avenue SE to provide 425 feet of stopping sight distance along the entire frontage of the proposed plat would require lowering the profile of 148'h Avenue SE for at least 700 feet and possibly much more, This improvement would necessarily extend beyond the plat frontage, Cuts of 2 y, to nearly 4 feet would be necessary 'for over 300 feet. Several hundred 'feet of a 12-inch water main would need to be dug up and lowered, At least two power poles would need to be relocated, water meters, dry utilities, ditches and culverts along this road reconstructed and several driveway approaches to 148'h Avenue SE rebuilt. The areas where the cuts would be greatest would probably need low retaining walls or rockeries at the edge of the right-of-way in order to accommodate the drainage ditch on the, side of the street opposite the proposed project. Some of this work would require easements from the abuttirig property owners, These improvements would be extremely costly and burdensome for the proposed plat. Furthermore, although limited survey data is currently available to make a definitive assessment, it appears that'it may be necessary to reconstruct the SE 116'h Placell48"' Avenue SE intersection to meet the reconstructed 148'h Avenue SE centerline profile, King County Road Standards Governing Frontage and Off-site Improvements The 1993 King County Road Standards addressing frontage and off-site road improvements require·these improvements to be based upon the impacts of the proposed development. To the extent improvements are necessitated by the development impacts, they must be done in conformance with the KCRS. These standards are set out in Section L03 Responsibility to Provide Roadway Improvements: A. Any land development which will impact the service level, safety, or operational efficiency of serving roads or is required by other County code or ordinance to improve such roads shall improve those roads in accordance with these Standards, The extent of off-site improvements to serving roads shall be based on an assessment of the impacts of the proposed land development by the Reviewing Agency B. Any lalld development abutting and impacting existing roads shall improve the frontage of those roads in accordance with these Standards. The extent ofimprovements shall be based on an assessment of the impacts of the proposed land development by the Reviewing Agency. (Emphasis added,) CamWest's attorney has advised them that the bolded language set out in these two provisions reflect Washington law regarding governmental authority to require roadway improvements as a condition of approving development proposals. Washington law limits the extent of required ,improvements to those that are directly related to the impact of proposed development, Even if the impact test is met, any required improvements must be proportional to the impacts of the development. (See Benchmark Land Company v, City of Battle Ground, 94 Wash. App, 537 (1999)) e:\2001 projects\01-002.04 east renton\camwesteast renton final g. norris memo.doc 10/15/01 (j) Memorandum October IS, 200 I Page 4 It order to determine whether CamWest can be required to provide SSD improvements across the entire plat frontage and beyond, the impacts of the proposed plat and the costs of such improvements must be assessed. '(Il'!sQ1"ulcll~:e'lfi~re'tl!that:!GJam\Wes~~Ra!1li,oM!JejJ2)at~ '1leweJe'pmeilti p'\octst"lttrt'!'1rp'l'I5"JitJe"'fh:l'iitage)mRrOVements,oncl48i1kAvenue'8E'to'lintlu"decutlV \¥Pl\!i.ri,~M;s'j1ffi;wal.gn The SSD issues associated with this area of 148 tH Avenue SE are preexisting and completely unrelated to the impacts of the proposed CamWest plat. There is no data that suggests the SSD condition on 148 th Avenue SE has created a safety problem or has significantly affected operational conditions 3 As discussed previously, road improvements to improve the existing SSD would be extremely costly and burdensome. Requiring the plat to fix the existing SSD condition when it did not create the condition, and when there is no safety issue associated with the condition would violate Washington law. Therefore, theFe;is'~legil1i,Il~§&~r~£)J1JL~~f.5m?.tag~..a!:'~lYSi:::li'l'provem,~n~, 1ffi'1'48 thcA'\feiftie'SE,to'impr6ye"SSD: ";'l .. ~:--<:'l~'!';~l::~::'\,~{'~:,·:'"·i'J ",-::..r :--,,_, -, '.. ' .... ;,...-J Need. for Variance .. A variance is unnecessary since Staff does not have the legal authority to require frontage and off- site improvements of the magnitude discussed in this memo. A variance would be needed only if the County had the authority to require the improvements for which a variance is sought. Conclusion Based on the foregoing information, we respectfully request you detennine that the proposed development should not be required to reconstruct the 148 th Avenue SE along the project frontage and off-site to correct a pre-existing SSD condition, and that a variance is not needed to meet the King County Road Standards. 3 The most pertinent factor applicable to the SSD standard would be imp.act on safety. To address this issue, the latest available three-year accident history was obtained from King County Department of Transportation which included the period between January 1, 1996 and December 31, 1999. According to the data provided, three accidents have occurred in the vicinity of the plat between 1996 and 1999. South of the proposed plat. at the SE 124th Street/148th Avenue SE intersection, there was one accident in 1996 and. one in 1997: both involving a vehicle striking a fixed object off the roadway. North of the plat. at the SE 116tl1 Streetl148t11 Avenue SE intersection, one accident occurred in 1999 involving a vehicle colliding with a bicyclist. None of th~ accidents were related to sight distance conditions across the plat frontage.) 9:\2001 projects\01-002.04 east renton\camwesteast renton final g. norris memo.doc 10/15/01 U) . '" \,~ ' .. KEY: Below curve, /35 storage not needed for capacity. ~ Above curve, further analysis recommended. I I II i / ~/ V/ II V \52/ \JII''' \.~) /0/ ~ ~ / P ~ / ~ ~ ~ - 25 20 15 10 s't % Total DHV Turning Left (single turning movement) (1) DHV is total volume from both directions. (2) Speeds are posted speeds. . Left-Turn Storage Guidelines (Two-Lane. Unsignalizedl Figure 910-9a Intersections At Grade Page 910-18 English Version 1200 1100 1000 900 800 :::. > I Cl ]i 0 I- 700 600 -d- 500 :f 1\ N. ~ 00 400 <;0 ----<\J 1Y'j.0:: to N1 I \ Ii > b: 300\-i\ :t: V) 0 ~ a ~ ~ ~ <t: ~ W -«: \9 \D .Design Manual May 2001 @ ':2. <;:: <:J C>I <l::. ;; ~I ,a ~ :J 2 s:.l. l= t L0 ...l • 0 . , .j , , ., :, J , ! GARRY STRUTHERS ASSOCIATES, INC. Memorandum 3150 Richards Road, Suite 100 Bellevue, W A 98005-4446 (425) 519-0300 (phone) (425) 519-0309 (fax) Date: October 2, 200 1 Project Name: Aster Park To: Michael Romano Project No,:01-002. 11 P:.l T: __ Centurion Development Services From: Garv A. Norris, P.E. Subject: Res onse to DOES Scree Memo Dated 5/4/0 1 ~ Aster Park and WSDOT 8124/01 c / RECEIVED ocr 03 2001 KING COUNTY I MID USE SER'q'ICES , The following memorandum was prepared to address issues identified in the plat Screening Memorandum dated May 4, 2001, in regards to the proposed plat of Aster Park. In addition, the memorandum responds to initial comments by WSDOT. The issues are restated with our response provided below. DDES ISSUES 4.a The traffic study should include peak hour distribution and level of service analysis for the a.m. peak hour at the SR 9001148th Ave. SE intersection. An AM peak hour turning movement count was collected at this intersection on July 9, 2001. The project trip distribution for the AM peak was estimated using the ITE AM peak hour directional distribution and the AM peak turning movement count. The result of the assignment is presented in the Technical Appendix as Figure I. The results of the AM peak hour level of service analysis for the SR-900/148th Avenue SE intersection is provided in Table I. Table 1 AM Peak Hour Level of Service 2003 2001 Existiog 2003 Without Project 2003 With Project Intersection With Project With Mitigation SR-9001148th Ave SE / NBLT' . F (60.0) (xx) -seconds of delay per vehicle F (158.2) F (199.3) E (35.7) 1-movement with the highest delay, the remaining movements will operate at an acceptable level of service. As shown in Table 1, the northbound left movement will operate at LOS F for the 2001 existing, 2003 without project and 2003 with project conditions. To mitigate the deficient level of service, an acceleration lane provided on SR-900 for northbound left turns would improve the AM peak hour level of service to LOS E. However, in discussions with WS,DOT, the proposed acceleration lane it not acceptable. 1\. L,," '0 ".0,,11"'1'1 ,J":,i ""'lli,." .,-1;,", f'J P1fUU }'V ~",.,.' ,~ "l·~~H-...... -·"··',i.".j' e:12001 projeclsI0l·C02. 11 asler parkltechmemoasterpark-co&wsdot.doc 10/2101 (j) . ~ .. .' I .... A. K,1'..I. u.s. .&,-----'l1 '\0 Richards Koa~. ~u~"". :~: Memorandum October 2, 200 I Page 6 In the event Stone Ridge does not proceed at this time and since a traffic signal is not warranted (see 4.c), Aster Park proposes to install acceleration lanes on SR-900 to facilitate northbound and southbound left turns and mitigate the level of service deficiency. With this improvement, level of ~ service for the northbound and southbound left turn movements will improve to LOS E and D, . ____ . TPI respectively. However, WSDOT has indicated that acceleration lanes are not acceptable. t::' 4.e The existing sight distance at the SR 9001148th Ave. SE intersection was not discussed in the traffic repon submitted with the plat application. Documentation should be provided to establish the existing sight distance at the intersection. Please evaluate the entering sight distance and stopping sight distance at this intersection, compliance with State sight_ distance requirements, and any proposed mitigation to correct sight distance deficiencies. GSA conducted an analysis of the existing entering and stopping sight distance at the SR- 9001l48th Avenue SE intersection per WSDOT standards. Stopping Sight Distance (SSDl SSD was calculated using an eye height of 3.5 feet and an object height of 0.5 feet. The minimum required SSD per WSDOT is 460 feet for SR-900 using a design speed of 50 mile per hour (mph). Per WSDOT the design speed is the posted speed limit plus to mph (posted speed limit is 40 mph). Table 6 summarizes the measured and required SSD on SR-900. Table 6 A roach I--::East (SR-900) West (SR-900) Stopping Sight Distance Measured (feet) 478 334' 460+ Re uired (feet) 460 460 I -distance includes curve in roadway, which may obstruct view of a 0.5' object in the centerline of roadway due to oncoming vehicles. 2 -distance includes only the straight portion of roadway, which provides an unobstructed view of a 0.5' object in center of roadway. As shown in Table 6, the measured SSD for the west approach meets the required SSD per WSDOT. For the east approach, the measured SSD of 478 feet exceeds the required SSD. However, it should be noted that the distance was measured through the horizontal curve. When vehicles traveling eastbound are present, they may temporarily obstruct the view of a 0.5-foot object in the center of the approach lane due to the curvature in the roadway. The measured SSD for the unobstructed section is 334 feet. Based on a review of the accident data, it does not appear that an unsafe condition exists on the east approach due to the limited SSD. Entering Sight Distance (ESD) The driver of a vehicle stopped, waiting to cross or enter a through roadway, needs obstruction- free sight triangles in order to see enough of the through roadway to safely complete all legal maneuvers before an approaching vehicle on the through roadway can reach the intersection. According to WSDOT, the minimum required ESD is 698 feet, based on a design speed of 50 mph and an available critical gap of 9.5 seconds per passenger car. Entering sight distance was measured from a point to feet behind the fog line on SR-900 at an eye height of 3.5 feet to an object height of 4.25 feet on SR-900. The measured ESD for the north approach looking west is 698+ feet and 533 feet looking to the east. The measured ESD for the south approach looking a:12001 projac1sI01-002.11 aslar parkllachmamoaslarpark-co&wsdot.doc 10/2101 ij) pr ....• Memorandum October 2. 200 I Page 7 west is 698+ feet and 411 feet looking to the east. Table 7 summarizes the measured and required ESD at the intersection. Table 7 Entering Sight Distance A roach Measured feet) Re Comment North looking West 698+ ESD met North looking East 533 698 Horizontal curve on SR-900 South looking West 698+ 698 ESD met South looking East 411' 698 Horizontal curve on SR-900 1-required entering sight distance per WSDOT Design Manual (May 2001), Figure 910-18a. 2 -line of sight is obstructed by tree branches on south side of SR-900 at 411 feet. As shown in Table 7, the entering sight distance for both the north and south approaches looking west meets the minimum required sight distance. For. the north approach looking east the entering sight distance is!5331eeb which is less than the minimum required sight distance. Th<: entering sight distance is ~o 533 feet due to the horizontal curve on SR-900. For the south approach looking east. the entering sight distance is@II feeQ which is also less than the minimum required sight distance due to the horizontal curve on SR-900. In addition, it should be noted that tree branches on the south side of SR-900 obstruct the line of sight from the south approach looking east. It appears the ESD for the north and south approach looking east could be improved by removal of the brush on the south side of SR-900 east of the intersection. In addition, as discussed in 4.c, acceleration lanes at this intersection are proposed if the plat of Stone Ridge does not proceed. Although acceleration lanes would improve the entering sight distance northbound left turning vehicles, WSDOT has stated that the acceleration lanes are not acceptable. According to Section 1.03, subparagraphs A and B, of the King County Road Standards, the extent of required off-site improvements is to be based on the impact created by the proposed development. In this case, the proposed plat does not create or exacerbate an existing deficient condition. Further, there is no documentation that suggests any safety problem is created by the existing entering sight distance deficiency. As previously mentioned, the accident rate at the SR-900/148th Avenue SE intersection is well below the statewide average for similar intersections. In addition, a detailed analysis of the types of collisions at this intersection was conducted to determine if the deficient entering sight distance on the east leg played a factor in the accidents. The accident data indicates that six of the eight accidents were "enter at angle" collisions. Three of the six "enter at angle" collisions involved northbound left turning vehicles and eastbound through vehicles. The other three "enter at angle" collisions involved a southbound stopped vehicle and a westbound right turning vehicle; a northbound through and an eastbound through vehicle; a northbound through and a westbound through vehicle. The seventh accident was a "rear end" collision involving two eastbound vehicles traveling straight. The eighth collision involved a northbound left turning vehicle striking the front end of a vehicle heading eastbound that crossed over the centerline. Therefore, based on the accident data, there does not appear to be a pattern between the accidents and the deficient entering sight distance on the east leg . • :12001 projectsI01-002.11 astar parkltachmamoasterpark-co&wsdot.doc 1012101 Ol ·1. 'Ii TRAFFIC IMPACT ANALYSIS FOR EAST RENTON January 16, 2002 . CamWest Real Estate Development 9720 NE 120th Place, Suite 100 Kirkland, W A 98034 fD) rn © rn ~ \VI rnl[)\ LrL~ APR 0 3 2002 ~ K.C. D.D.E.S. " Traffic Impact Allidysis East Rentol! ~~~~~=-----~------------~----------------~ !' TABLE OF CONTENTS INTRODUCTION "",'" .. " .... ,", .. , ............. ".,"' .. ,"""""', ........ , ....... " .. ,', ... ,', .. , .. ,"", .. , .. ,', .... , ..... ", .. ,', .... , .. ", .. ,. 1 PROJECT DESCRIPTION ........ "", .. ,""','" .. , ... ,"",""", ......... , ..... , .... ,',"', .. " .. ,", .. , .. , .. ,', .... ,""""', ...... " .. " ..... 1 EXISTING CONDITIONS """,", .. ,',',", ....... ,'" ...... ,"', .. " .. ,""""", .. ,"',,', ... , .. ,", ...... , ... , ...... , .. ,"',', ..... ,"", ..... , 1 Road ways" .. " .. , .. , .. "" .. :, .. """, ...................... ,', .. , ... , .... ,""",', .. ,',', ... ,", .. ,", .. ,"', .. ',',',', .. ,""""",',",",", ... ,"," 1 148'" Avenue SE .. , .. " .. ,",',""', .. , ""', ........ " .. , .... , ..... ,""",: .. ,""", .. ,"', ..... ,', .... ,"", .. , .. , .. " ........ " .............. ,' 1 SR -900 , .. ,", .... , ... ,", ...... ,"", .......... , .. " ... , ... ,', .... , ... , ..... ,", .. , .. ,"', .. , ... ,", .. , .. ,", .. ,""', .. , .. " .. , .... ,""", .. ,"", .... " 4 TransitlNon-Motorized Facili ties"" .. " .. ,"', .. ,"', ... , ... ":" .. ,", .. ,"""", .. ,"""", .. , .. ,, ....... ,', .. ,",.,"", .. , .... ,"""', .. 4 Transit", .... , .. ,"", .... , .. ,', .... , .. , .. " .. ,; ..... ,""""""'" ... """, .. , ... "' .... " .. """""' .... ""' .. , .. "' .... "' .. ", .... " ... ""' ...... 4 Non-Motorized Facilities":"""""",,, .. , ......... , .. ,','," .. ', .... , ... , .. ,"', .. ","",', .... ,", ...... ,', .. , .. ""',", .. ,""""',', .. 4 Traffic Volumes .. , .... " .. " ...... ,""""""""', ... , ... ,"""",',"""""", .. , .. , ... ,"', ... ,""', ...... ," ..... ,', .. " .. " ... """',',"",' 4 Level of Service" ..... " .......... ,"', .. , .. ,""', ......... , .. ,,:,',"""""""',.,' ..... ,' .. , .. ',."',',, .... ,"', .. ,', .. ,', .. ,,""""', ... ,', .. ,' 6 Accidents" ...... "", .... , .. " .. , .. """."".""" ........ , .. """, .. , ,,:,"""""", ..... ,', .......... ,',""""", .. " .. ,', .... ,",', .. ' ...... , .... 7 Planned and Programmed Improvements ..... ,' .. , ... , .. """""",.,", .... ,",",., .. , .. ,", ..... ,', .. ,',', .. ".,', .. , .... , .... ,,' , .. ,,8 FUTURE CONDITIONS WITHOUT PROJECT """", .. ,"',""."',,', .. ,, .... , .... ,""',"",., ..... , ... , .. , .... , .. , ......... , .. ,' 8 Background Traffic Vo!umes ........... : ........... ~ ........................................................................ " .................... 8 Pipeline Projects" .. ,', .. ,"', .. , .... ,', .... ,',.,"',.,', .... ,', ....... " .. ,', .. ,"""", .... ,", .. ,', .... ,"", .. ,", .. ,""", .. ,", .. ,"""", .. 9 Level of Service .......................................................................................................................................... 9 FUTURE CONDITIONS WITH PROJECT .. , ........................................................................ , .................... 11 Traffic Vol urnes, .. , .. ,', .. " .... ,""', ... , .. "., ...... " .. , .. ,""""""""""', .... ,", .. ,""""", .. " .. , .. , .. " .... ,"""", .. ,"""""'" 11 Project.Trip Generation "", .. " ...... ,""', .. : .. , ..... ,"', .. ,""""', ...... : ......... :,"", .... ', ........ , .... ,,",", .. ,.,""",',,',,' 11 Trip Distributionffraffic Assignment ....................................................................................................... 12 Level of Service ..... ,' .... , .... , .. ,"", ...... ,", .... ,', .. ,' ...... , ...... ,,"""""', .... ,',',,' .... , "', .. """', .... , .... " .. ,',, .. ,', ... "", ... 12 ,_;;~?ig~t Di~~~~nc,e. Analr5s1~.~i ........ ~ .......... "'~ .. ; ................................. : .................... , ........ , ............................... 15 Turn Lane Warrant Analysis .. ", .. """ ".,', ..... ,,", .... ,', ...... , .. ,"" "",:,"'" "'" , .... ,""""', .. ",'".,',', .... ,""""""'" 16 CONCLUSIONS " .. ,"" .. ,,''''''', .... , .. ,',''''.''', .. ,''','', ... , ... ,'''', ...... ".,.,"", .. """"',', .. , .. ,"""", .. ,,',",.,,, .. ,,"""."",16 TRAFFIC IMPACT MITIGATION """""""""""""""""" ' ...... ,""""' .. ,""" "',"', ...... " .... ,"', .. , .... ,,.", ..... ,'" \7 Garry Struthers Associates, Inc. Traffic Impact Analysis East Renton INTRODUCTION The following report was prepared to address King County's traffic impact analysis requirements for the P.reliminary Plat of East Renton located at 12013 148 th A venue SE in the Renton area of unincorporated King County. A vicinity map is presented in Figure 1. As specified in the King County Integrated Transportation Program (ITP), intersections impacted by 30 or more peak hour project trips and at least 20 percent of the total peak hour project traffic were selected for evaluation. Based on the transportation concurrency model distribution for this site, it was determined that the proposed project would impact two intersections -SR-9001148 th Avenue SE and SE 116 th StreetJl48 th Avenue SE. This report summarizes the process, findings, conclusions and recommendations of the traffic analysis. PROJECT DESCRIPTION East Renton is a preliminary plat consisting of 68 single-family lots. King County zoned the subject parcel R-4, which allows 4 dwelling units per acre. Currently, there is a single-famii y residence on the property, which will be removed as part of the proposed development. The plat is expected to be fully occupied by 2005, whIch for the purposes of this analysis is assumed to be the horizon year. East Renton will offer a single point of access to I48 th Avenue SE. The internal road system will be built to King County standards. In addition to providing access to the proposed lots, the internal road system will provide road stubs to adjacent properties to the north and south. A preliminary site plan is presented in Figure 2. EXISTING CONDITIONS The Existing Conditions analysis provides a statement of the traffic-related conditions within the study area at the time of the writing of,this report. The statement includes a discussion of the existing roadway, transit, pedestrian and bicycle facilities serving the site; identification of existing peak hour traffic volumes and accident history at the analysis intersections; and identification of proposed transportation improvements in the area. Roadways The roadways impacted by the proposed development include 148 th Avenue SE and SR"900. These roadways are discussed in the following sections. . 148,1> Avenue SE I48 th Avenue SE is a two-lane collector arterial that runs north-south. The paved roadway width is approl(imately 28 feet and includes two II-foot travel lanes, a 5-foot shoulder on the west side of the road and a 2-foot shoulder on the eastside. Traffic control includes stop signs at the SR- 900 and ~.~.! 28 th Street intersections. JTh:epQst.eLI-~pee<;!.-ljIJ1iFon:I"48C~?Av:~.ue:~E.;is~3::!nile~:p per-hour'(mphl:(> '--' _. __ .-~-. -.•. ....... . -. -. .. L -.""r _ -1 Garry Struthers Associates, Inc. Page 1 , ~GAR.RY S"TRUTHERS AssoclA1'es, INC. • 31GO __ ."""'-'OO ~ ~ __ .WA~ ~ PI'>cnoI: (~2l5) &1l1-0300 • F...,(-425)&11l-Q3Ql1 E ....... I: g Q", ..",,!IlQ,-n hIIp,;-.~......, VICINITY MAP FIGURE 1 PARK & RIDF: EAST RENTON \ , I L ________ _ I-----------·---·------·---·'·------'-·---'-~------.. ,-,------.--_.,--_.-,-... ---,._-,._- I I I I I I I I i I I(C R-4 o I I KC F(-4- I t----------------.-----~.-------.----.------C. "------'-1 I i SITE PLAN FIGURE 2 I L o KC i I I EAST RENTON T~affic Impact Analysis·· East Renton SR-900 SR-900 is a two-to five-lane principal arterial that runs east-west. In the vicinity of 148 th Avenue SE, the pavement width is approximately 32 feet with two 11-foot travel lanes and 5-foot shoulders. Traffic control includes signals at 138 th Avenue SE and 164 ti1 Avenue SE and stop signs on the side streets.' The posted speed limit is 35 mph west of l48 th Avenue SE and 40 mph east of 148 th Avenue SE. TransitfNon-Motorized Facilities Transit King County Metro provides transit service in the vicinity of the site. Route 114 provides weekday service between the Renton Highlands and downtown Seattle via SE 138 th Street and Coal Creek Parkway SE. Weekday service for Route 114 operates with approximate 30-minute headways during the commuting peak hours. Route240 provides weekday and weekend service . between downtown Renton and Bellevue via 138 th Avenue SE and Coal Creek Parkway SE. This route operates with 30-to 60-minute headways during the weekdays and 60-minute headways on the weekend. Transit service is also available at the Renton Highlands Park & Ride located approximately three miles from the project site which serves Metro Routes 105, 111, and 909. Routes 105 and 909 provide weekday and weekend service to the Renton Transit Center and Route 111 provides weekday service to downtown Seattle. Non-Motorized Facilities There are no sidewalks or pedestrian facilities along either side of 148 th Avenue SE in the vicinity of the proposed site. . According to staff at Apollo Elementary, 15025 SE 117th Street, all students are bused to the school since there are no facilities whic:h provide safe pedestrian access. Maywood Middle School, 14490 168th Avenue SE, buses all students except those who live within a mile radius. Bus transportation is also provided for Hazen High School located at 1101 Hoquiam NE. Traffic Volumes Existing PM peak hour traffic volumes at the analysis intersections were determined from September 2001 turning movement count. The, existing PM peak hour volumes are presented in Figure 3. Garry Struthers Associates, Inc. Page 4 " . Iii ~ ~ ~ e w on ~ '" ro ~ NOT TO SCALE jlL N 35 --.J 393- 64 ---, N'" L12 _ 509 ,4 ill LlO ~--_0 jlL ,'3 --.J ill 5 1 2 ---, ._'" ~~- SITE w '< ~ ! SE 116TH ST SE 117TH ST OTH S1 SE 12BTH ST EXISTING TRAFFIC VOLUMES FIGURE 3 w on ~ ~ :" xx -PM PEAK EAST RENTON Traffic Impact Analysis" East Renton Level of Service Level of service (LOS) is used to qualify the degree of traffic congestion and driver comfort on streets or at intersections. The Highway Capacity Manual (HCM) describes the methodologies for calculating LOS on street segments and at signalized and unsignalized intersections. According to the HeM (TRB Special Report #209), there are six levels of service, which describe the operational performance of the roadway system. The levels range from LOS A, which indicates a relatively free-flowing condition, to LOS F which indicates operational breakdown. The level of service for a two-way stop controlled (TWSC) intersection is determined by the computed or measured control delay and is defined for each minor movement. Level of service is not defined for the intersection as a whole. Average control delay less than or equal to IO seconds per vehicle is defined as LOS A. For LOS F, the average control delay is greater than 50 seconds per vehicle. The LOS fot signalized intersections is defined in terms of average control delay per vehicle for the entire intersection, The criterion for LOS A is an average control delay of less than or equal to \0 seconds per vehicle. The criterion for LOS F is an average control delay of greater than SO seconds. King County has adopted level of ser"ice E as the county road standard. According to the King County Integrated Transportation Program (ITP), any development that impacts an intersection with 20 percent of the peak hour project generated trips and 30 project generated peak hour trips must insure LOS E with full development of the project. Level of service for the analysis intersections was calculated using SynchroTM 5.0 and HCS™_ 2000, computer software programs based on the 2000 Highway Capacity Manual. As stated previously, the intersections meeting the impact criteria are SR-9001148'h Avenue SE . and SE ll6'h Streetfl4S'h Avenue SE. The results of the existing condition level of service analysis are shown in Table 1. -. Table 1 2001 Level of Service Intersection SR-9001148" Ave SE NBLTI SE 116'h Stl148'h Ave SE 'EBLT1 (xx) -seconds of delay per vehicle Traffic Control Two-Way Stop Two-Way Stop 2000 Existing LOS Standard F (69.4) E B (ID.2) E 1 -level of service for the two~way stop controlled intersection represents the movement with the highest delay. The remaining movements operate .at an acceptable level of service. As shown in Table 1, the SR-900/14S,h Avenue SE intersection currently operates at LOS F and the SE 116'h StreetJ14S'h Avenue SE intersection operates at LOS B. Garry Struthers Associates, Inc. Page 6 Traffic Impact Anal)'sis East Renton .~~~~~~----~------------------------------~~~ Accidents The most current accident data for the analysis intersections was obtained from WSDOT, for the three-year period from January 1998 to December 2000. In addition to the analysis intersections, accident data for the SR-9001l641h Avenue SE intersection is included since it is considered a high accident location (HAL), According to WSDOT, accident data for 1999 and 2000 have been entered into the system, however, some data fields are still missing. Although some of the data fields are missing, the total number of accidents has been recorded. However, only 64 percent of the 1998 data has been entered. The available three-year accident history is summarized in Table 2. Table 2 Thrce-Year Accident History Rear-end Enter at angle Front end (not head-on) Intersection Total Enter at angle Front end (not head-on) Pedestrian Head-on Object Intersection Total 1) 2 2) -Property damage only accidents No. of Reported Accidents , 1998 1999 2000 2 2 2 4 4 4 4 3) -Accident rale per million entering vehicles 4) -Average accident rate state~wide for this type of intersection per WSDOT 2 2 3 1 6 8 5 5 1 1 1 21' Acc. ,Avg. 0.57 1.30 5) -Listed as a "enter at angle", however, it is coded as a front end (not head-on), with one of the vehicles crossing over the centerline or through median. As shown in Table 2, a total of 8 accidents have occurred during the latest three-year period at the SR-9001l481h Avenue SE intersection. Of the 8, there were 6 enter at angle, I rear-end and I front end. The accident rate at the SR-900114S lh Avenue SE i~tersection, however, is well below the statewide average for similar intersections. At the SE I 16 1h Streetl1481h Avenue SE ' intersection, one bicycle collision occurred during the latest three-year period. As shown in Table 8, there were a total of21 collisions at the SR-90011641h Avenue SE intersection between 1998 and 2000. Of the 21, there 8 were rear-ends; 5 enter at angles; 5 front ends; 1 pedestrian; 1 head-on; and I fixed object. Garry Struthers Associates, Inc. Page 7 , , Traffic Impact Analysis East Renton It is assumed the accident rate for each of the intersections will remain the same in the future. As such, with increased traffic, it is likely there will be a corresponding increase in accidents. However, it does not appear that the relatively small increase in traffic would create an identifiable safety hazard. Planned and Programmed Improvements A review of King County's Planned and Programmed Transportation Improvements indicate the following transportation improvement projects planned in the study area. King County's 1999 Transportation Needs Report (TNR) • SE May Valley Road (Coal Creek Parkway to SR-900), NC-42. This project includes widening travel lanes and paving shoulders. In addition, this project would also include the constmction of equestrian facilities. Both King County and the City of Newcastle would fund this low priority project. • Coal Creek Parkway at SE May Valley Road, NC-lO 1. This project includes widening the north and south legs of this intersection to provide additional channelization. King County would fund this high priority project. King County's Pipeline Project(s) Improvements • A traffic signal is to be installed at the 148'h Avenue SE/SE 128'h Street intersection as part of the mitigation requirements for the Maplewood development located south of SE 128th Street between 148th Avenue SE and 152nd Avenue SE. In addition, left-tum lanes for the east and west approaches will be constmcted at the intersection. The south approach will be constructed with an exclusive right turn lane and a shared left/through lane. FUTURE CONDITIONS WITH OUr PROJECT The Future Conditions Without Project analysis provides a discussion of the traffic-related conditions in the horizon year without the proposed project. This section includes a discussion of background traffic volumes and level of service at the analysis intersections. East Renton is expected to be fully occupied by 2005, market pennitting. Therefore, 2005 for the purposes'of this analysis is considered to be the horizon year. Background Traffic Volumes Background traffic volumes for the 2005 without project condition include the 200 I existing PM peak hour traffic volumes, plus known pipeline projects in the vicinity of the site, plus area-wide traffic growth. A growth factor of 2.57 percent per year was used based on the area-wide historical growth in traffic provided by WSDOT. Garry Struthers Associates, Inc. Page 8 , , • Traffic Impact Analysis East Renton Pipeline Projects A pipeline project is defined as a proposed development which submitted a complete application in advance of East Renton, and is expected to be fully developed and impact the transportation system within the horizon year of East Renton. According to King County, there are several pipeline projects in the general vicinity of East Renton. Trip generation for the proposed projects is' presented in Table 3 . Table 3 . Pipeline Projects 6 sfdu's 4 mfdu's 142nd Ave SE between 11400 & 11600 2 sfdu's 'SR-900114S ili Ave SE 37 sfdu's 14429 SE 116 ili St 20 sfdu's 13715 SE 116th St 3 sfdu's. IISI3 14S'h Ave SE 60 sfdu's 5001 SE I Street N. & S. side of SE 12S ili St 45 sfdu's 14606 SE 136th St 21 sfdu's 5715 SE 12S ili St 7 sfdu's 5710SE 128 th St 7 sfdu's 5S00 SE 128 th St S sfdu's S. ofSE 12S ili St, btwn 14S th Ave & 152nd Ave 21S sfdu's 618 SE 128 th St 124 sfdu's 2 45 21 7 7 8 21S 125 1 24 13 2 39 4 5 140 SO 1 13 7 16 S 3 3 3 7S 45 As shown in Table 3, there are eight pipeline projects identified by King County and eight identified by the City of Renton in the vicinity of the project site. Trip distribution/traffic assignments for the pipeline projects were determined based upon the Transportation Concurrency run for East Renton provided by King County. Level of Service The results of the 2005 background without project PM peak hour level of service analysis a~e shown in Table 4. The existing level of service is shown for comparison purposes. Garry Struthers Associates, Inc. Page 9 ~ 0- 0< UJ UJ '" U ~ u UJ '" ~ iE " C:! ~ ~ ~ ~ e w '" UJ ~ iE " C:! NOT TO SCALE '''1'''' . ',. " .. , .. - """ L'5 """ -_ 563 )IL ," 58 -.-J lli 435- 98 1 ~-~ "'~'" SR-90 UJ "''' L" '" ,,--_0 ~ JIL ,14 I iii 6 -.-J lli :! , 2 " SE 116TH ST 1 -" ,,-- SE 11TIH ST SITE 120TH ST SE 128TH ST PROJECT VOLUMES 2005 WITHOUT TRAFFIC FIGURE 4 UJ '" w ~ ~ ~ xx -PM PEAK EAST RENTON , . . Traffic Impact Analysis' East Renton Table 4 2005 Without Project Level of Service . Intersection 2001 Existing 2005 Without Project LOS Standard SR-9001l4S'" Ave SE NBLT F (69.4)' F (578.3) E SBLT F (160.1) 2 E SE 116'h StlI4S'" Ave SE EBLT' B (10.2)' B (11.2)' E (xx) seconds of delay per vehicle 1 ~ level of service for the two~way stop controlled intersection represents the movement with the highest delay. The remaining movements operate at an acceptable leveL 2 -movement will also operate below an acceptable level. As shown in Table 4, the SR-9001l4S,h Avenue SE intersection will operate below the level of service standard in 200S without project. The SE 116th Streetl14S th Avenue SE intersection is estimated to operate at an acceptable level of service (LOS B) in 200S without the project. FUTURE CONDITIONS WITH PROJECT The Future Condition With Project analysis provides a statement of what traffic related conditions will be like in the horizon year with the project. The analysis simply adds anticipated project impacts to the horizon year background conditions. The analysis defines anticipated project trip generation and evaluates impact through a level of service analysis at the analysis intersections. Traffic Volumes Traffic volumes for 200S with project condition include 200S without project PM peak hour 'volumes discussed above plus expected PM peak hour traffic to be generated by East Renton .. Project Trip Generation Trip generation for East Renton was calculated using the trip generatio'n rates for Single-Family Dwelling Units, Land Use Code 210 presented in the Sixth Edition of the Institute of Transportation Engineers Trip Generation Report, 1997. A summary of the anticipated trip t generation for East Renton is presented in Table 5. ·Table 5 Trip Generation AM Peak PM Peak Land Use AWDT Total In Out ToM In Out Proposed East Renton 68 sfdu's 651 51 13 38 69 44 25 Existing Residence 1 sfdu 10 I 0 1 I 0 ._----_ .. ---- Net Impact 641 50 13 37 68 43 25 Garry Struthers Associates, Inc. Page 11 Traffic Impact Analysis East Renton As shown in Table 5, East Renton is estimated to generate 651 daily, 51 AM peak hour and 69 PM peak hour trips in the 2005 horizon year. The net traffic impact of the project was determined by deducting the existing site trip generation from trip generation expected with the proposed development. The net traffic impact is 641 daily vehicle trips, 50 AM peak and 68 PM peak hour trips. Trip Distributionffraffic Assignment Trip distribution percentages for East Renton were based on the traffic assignment provided by King County Transportation Planning as part of the Transportation Concurrency Analysis for the proposed Aster Park development located at the SR-9001148 th Avenue SE intersection. Trip distribution percentages for the pipeline projects were derived from the percentages determined for the East Renton analysis. The results of the trip distribution/traffic assignment process for project-generated trips are presented in Figure 5. A summary of ihe 2005 with project PM peak hour volumes are presented in Figure 6. Level of Service The 2005 with project PM peak hout level of service at the analysis and site access intersections are provided in Table 6. The existing condition and 2005 without project PM peak hour level of service are provided for comparison. Table 6 2005 With Project Level of Service Intersection 148~ Ave SE/Site Access EBLT' S'R-9001148~ Ave SE NBLT SBLT With Signal 3 SE 116'" StlI48'" Ave SE EBLT' (xx) -seconds of delay· per vehicle 2000 Existing F (69.4)' -. B (10.2) 2005 Without Project F (578.3) F (160.1)' B (11.2) 2005 With Project A (8.5) F (1902.0) F (220.1)' A (8.2) B(I1.6) LOS Standard E E E 1 -level of service for the two-way stop controlled intersection represents the movement with the highest delay. The remaining movements operate at'an acceptable level. 2 -movement will also operate below an acceptable level 3 -signal currently under design by pipeline development As shown in Table 6, the site accessl14S lh Avenue SE intersection will operate at an acceptable level of service in 2005 with the project. The SR-900114Sth Avenue SE intersection will operate below the level of service standard in 2005 with the project. The SE 116 th Streetl14S th Avenue SE intersection will continue to operate at a LOS B in 2005 with the project. Garry Struthers Associates, Inc. Page 12 ~ j ~ '-8 w "' ~ ~ ~ w "' NOT TO SCALE (36%) ll( " (21 %) -9 (30%) 14 j I 8 w "' ~ '" ~ '" ;': 26 j I 15 . '. ' SR-90 s 117TH ST SE 116TI-l ST ~ OJ j 15 ~ l SITE 10TH ST 10 , CO 9 15 SE 128TH ST PROJECT-GENERATED TRAFFIC" VOLUMES FIGURE 5 • w "' ~ ~ ~ 2 (5%) xx -PM PEAK EAST RENTON · ~ "- '" w w '" u "-° u p V> ~ ~ => B w V> W .. ?;: ~ ~ NOT TO SCALE jlL " 56 ~ 435- '07 1 0" L'5 _ 563 ,14 iIi Lll "N _ _ 0 jlL ,14 IIi 5 ~ , " 2 1 "" ,,-- SITE w V> W " I in ;': SE 116TH ST S 117TH ST 120TH ST SE 128TH ST 2005 WITH PROJECT TRAFFIC VOLUMES FIGURE 6 w V> w " I ';; ~, xx -PM PEAK EAST RENTON , , East A signal warrant analysis was conducted fot the SR-900/148,h Ave,nue SE. Results of the analysis indicate that a signal is not warranted at this intersection in 2005 with the project. However, the King County Examiner required a signal and other improvements at this location as mitigation of the traffic impacts generated by the plat of Stone Ridge. Stone Ridge is approximately located on the west side of 148<h Avenue SE, approximately between Northeast 16 th Street and Northeast 18 th Court. Stone Ridge is required to provide the following traffic- related improvements for final approval: • Construct eastbound and westbound left turn lanes on SR-900, at the SR 90011 48 th Avenue SE intersection. • Modify the east leg of the SR-900/l4S th Avenue intersection as necessary, to meet WSDOT stopping sight distance requirements. (Note that per the applicant's engineer, this can be achieved by the clearing of vegetation along SR-900.) In addition, the applicant shall clear vegetation within the right-of-way along SR-900, east of 148'h Avenue, to maximize the entering sight distance for the north and south legs of the intersection. • Construct a traffic signal at the SR-9001l48'h Avenue SE intersection. This work shall be completed either individually, or in conjunction with other developments in the area. If Stone Ridge provides a new traffic signal at the SR-900/148th Avenue SE intersection as required for final approval, the existing and horizon year level of service deficiency will be mitigated. In 2005 with East Renton, the level of service would improve to an acceptable level (LOS A) with the proposed signal. Therefore, no additional level of service mitigation would be required for East Renton. The required improvements are currently under design by Stone Ridge. Sight Distance Analysis A field study of stopping and entering sight distance was conducted on April 18, 200 1.!'j:'12~~/ (j:J.;;eEsse~ ac~ess~~:~~a~,at ~tnanilne ~~~app~~xLl11atej r (2~ Te.e\ ssutll , of~t~~hn oJ:ih--P':~perty7 ~hne. ;The stoppmg slgntalstance'(SSD) at the sIte access mtersectlcin WIth 148 Avenue SE was <'65Strved'to be 318 feet for southboundyehicles and 425+ feet for northbound vehicles. The posted speed limit on 14S th Avenue SE is 35 mph. The King County Road Standards (KCRS) does not stipulate the design speed used to calculate SSD. King County has administratively chosen to use the posted speed plus 10 mph for design speed. Based upon a 45 mph design speed (posted flQf 35 + 10 mph), SSD of 425 feet would be reguired for northbound vehicles an 400 feet d vehicles under the KCRS. (The increase of 25 feet in the SSD fQr the n nd direction is the result of a correction for downgrade specified in KCRS 2.12. The KCRS does not identify an adjustment to reduce SSD for the upgrade condition. I Adding 10 mph to the posted speed to calculate design speed increases the required SSD by 150 feet over what would be required for a 35 mph design speed. If a 35 mph design speed is used t According to the American. Association of State Highway and Transportation Officials (AASHTO) Green Book (1984), page 143, "Design Speed is used in calculating downgrade corrections, average running speed in calculating upgrade con·ections." Garry Struthers Associates, Inc. Page 15 Traffic Impact Analysis· East Renton then the required SSD per the KCRS is 250 feet in the southbound direction and 265 feet in the northbound direction. It should also be noted the KCRS adopted'the highest value stopping distance (400 feet) for a 45 mph design speed, established by American Association of State Highway 'and Transportation Officials (AASHTO). AASHTO is the agency that establishes national standards, including SSD, upon which the KCRS is based. According to ASHTO, the assumed speed for a 45 mph design speed ranges between 40 and 45 mph, with a calculated SSD ranging from 325 feet to 400 feet. Based on a recent speed study on 148'h Avenue SE in the vicinity of the proposed plat, the 85- percentile speed is 40 mph.2 ' , King County requested CamWest Development, Inc. reconstruct 148'h Avenue SE along the plat frontage and to the north of the proposed plat, or obtain a variance to meet KCRS for stopping sight distance. This issue was first raised in 1999 with Harbor Homes, the previous project applicant for the property, and was raised again in a meeting between the CamWest Development Design Team and King County staff on Thursday April 19,2001. A response to the deficient stopping si ht distance is provided in a memorandum to King County DDES from Garry Struthers Associates, Inc. ated August 8, 2001 (Technical Appendix). Based on the infonnation provided in the memorandum, Cam West requested King County determine the proposed development should not be required to reconstruct 148'h A venue SE along the project frontage and off-site to correct a pre-existing SSD condition, and that a variance is not needed to meet the King County Road Standards. An analysis of the entering sight distance (ESD) at the initially proposed access indicated the project would not meet the KCRS required entering sight distance (ESD) for vehicles approaching from the north (the critical ESD movement). In the field study of sight distance discussed above, 390 feet of ESD was observed at the proposed site access compared to the KCRS requirement of 620 feet. [? proviaetne,620';'feetof"ESD Cam West T,el cat--_ ~ e ] ;f'access intersectiOifWit -• S,h:Avenue ." "'0-eft' line: A::ftliis-19cliti9!l'!1~c~eptal:ire ~=~'!'1" s.1.s.1£YF1:§~I~Ut~i}.~.':.cs.,:p~~~i~a<~hlii9Cit\oil:~.sing a 45 ·mp!J.de.~igp sp_e.ti:c!i-':--". . . Turn Lane Warrant Analysis " A left·turn lane warrant analysis at the site access on 148 th Avenue SE was conducted. The results of the analysis indicate a left-tum lane is not warranted. CONCLUSIONS The plat of East Renton will not create any significant adverse conditions on the surrounding transportation network. The plat will generate approximately 641 daily vehicle trips, SO AM peak and 68 PM peak hour trips to the transportation network. As determined from the analysis, project impact is limited to the SR-900/148 th Avenue SE and the SE 116'h Streetl14S,h Avenue SE intersections. The SR-9001l48'h Avenue SE intersection 2 The speed study was taken from 12:00 AM Tuesday May 7 to 12:00 AM Wednesday May 8, 2001. The counters were stationed 50 to 75 feet north of the north property line. Garry Struthers Associates, Inc. Page 16 r-----------------------------------_-------~----- I Jraffic Impact Analysis East Renton was detennined to operate at an unacceptable level of service in the 2001 existing condition and in 2005 with and without the project. With the installation of a signal constructed by pipeline development, the level of service will improve to LOS A in 2005 with the project. The SE 116 th Street/14S th Avenue SE intersection was estimated to operate at an acceptable level cif service for the existing, 2005 with and without project conditions. It should be noted that the addition of the project traffic will not change the qualitative level of service at either analysis intersection. /fas.e.?J~l} th.~ preliminill.Y response from Klng:Couhty, !!!fp.r.oposed· development ~is' riot required» 7 r-t6TecohstrucCl48 th -Avenue 'S Fal6ng tl1e<> project fton tllge an d-off csi te to'correct ap're-exi sting--)? ··SSD~o~dit;on,;nd:thatavariahceis not ~~eded to ,meet-the-King County Road Standards/ It is anticipated that the proposed project would not impact Metro's transit operations in the surrounding area. TRAFFIC IMPACT MITIGATION East Renton is required to pay a Mitigation Payment System (MPS) fee of $198,084 based on $2,913 per unit (68 units) for concurrency zone 442. If the proposed platof Stone Ridge provides a new traffic signal at the SR-9001148th Avenue SE intersection (required for final approval), the existing and horizon year level of service deficiency will be mitigated. In 2005 with East Renton, the level of service would improve to an acceptable level (LOS A) with the proposed signal. Therefore, no additional level of service mitigation would be required for East Renton. '\ Garry Struthers Associates, Inc. Page 17 _ i , , East Renton SE 116th Street/148th Avenue SE PM PEAK HOUR Collected Sept. 26, 2001 -"' ro w o. ::; o. ;:; 0 N EBLT 5 EBT 1 EBRT 2 WBLT 13 WBT 0 WBRT 10 NBLT 6 NBT 71 NBRT 15 SBLT 15 SBT 122 SBRT 6 266 10/12/012:53 PM .<: ~ e '" "C C ~ e '" -"' u ro co 1 0 0 1 0 1 1 8 2 2 13 1 30 13 w 13 "e- CL w 'e-o. w .5 w .5 W "-a: W "- c .9 a: c w 0 a: () '0 '" c C " (3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 26 13 0 0 0 0 34 12 0 0 60 25 ~ 13 w "e-o. '5 0 .<: ~ U") 0 0 N c .9 c w a: '" ro w 13 w "e-o. £: ~ U") 0 0 N .9 u ro LL S 0 I -"' ro w .o. w ~ ~ ~ -"' u 2 >-- C w ~ w o. 6 0 6 1 0 1 0.47 0 2 0 2 14 0 14 0.77 0 0 0 0 11 0 11 , 7 0 7 118 15 133 0.86 0 17 0 17 17 0 17 181 26 207 0.86 0.0 7 0 7 381 41 -422 East Renton 148th Avenue SElSR-900 PM PEAK HOUR Collected Sept. 26, 2001 , -" ro " "- :> "- 0 0 '" EBlT 35 EBT 393 EBRT 64 WBlT 4 WBT 509 WBRT 12 NBlT 38 NBT 31 NBRT 25 SBlT 14 SBT 63 SBRT 27 1215 10/121012:53 PM -------------- 2 u " 2 u "e- "- " " .c '3 e (!) "0 C ~ e '" -" u ro <D "e- "- " c 15 c-o: ci 0 '" c ;z .s 0; c-o: c £ c " a: a ;,;. G 4 19 0 42 0 0 7 21 6 0 5 2 54 0 0 1 2 0 4 10 4 3 11 6 3 4 3 1 3 0 7 23 4 3 8 0 129 106 25 -. m u " 'e- "- " :S' ~ '" 0 0 '" c £ c " a: <;; ro w 13 " 'e- "- :; ~ '" 0 0 '" ~ ro "- '3 0 I -" ro " "- " m ~ %: -" u 2 f0-e " ~ " "- 58 0 58 435 0 435 . 0.96 0.6 98 9 107 11 3 14 0.87 563 0 563 0.8 15 0 15 56 5 61 51 8 59 0.84 0 35 2 37 18 ·0 18 97 14 111 0.78 1.0 38 0 38 1475 41 1516 i. 1· , , East Renton Site Access/148th Avenue SE PM PEAK HOUR Collected Sept. 26, 2001 '" ro " a. :; a. 0 0 OJ EBLT EBT EBRT WBLT WBT WBRT NBLT NBT 92 NBRT SBLT SBT 137 SBRT 229 10/12/012:53 PM .c ~ e CJ "0 C ~ e '" '" 0 ro <Il 0 0 0 0 0 0 0 10 0 0 15 0 25 !'l 0 " !'l 0 'e-o. " " 'e-o. w .s c ~ "-0:: 0; c- c .9 o:: c " ,; IT: () 15 '" c '" 8' 0 0 0 0 0 0 0 0 0 0 0 0 0 0 26 13 0 0 0 0 34 12 0 0 60 25 -- w 13 " 'e- <L :; 0 ~. "' 0 0 OJ c 0 c " IT: ;;; ro UJ 13 " 'e-o. E >: "' 0 0 OJ .9 0 ro LL ~ ~ 0 I '" '" " 0. " w ~ ~ '" 0 2 f-- 1: " ~ " a. 0 15 15 O· 0 0 0.47 .0 0 10 10 0 0 0 0.77 0 0 0 0 0 0 0 0 17 17 141 0 141 0.86 0 0 0 0 0 0 0 198 0 198 0.86 0.0 0 26 26 339 68 407 , . . TWO-WAY STOP CONTROL SUMMARY General Information Site Information [Analyst JMS Intersection SR-900/148TH AVE SE IAQency/Co. GSA kiurisdiction KING COUNTY Date Performed 10-01-01 (Col/ected 9-26-01 IAnalysis Year 2001 EXISTING IAnalysis Time Period PM PEAK Project 10 EAST RENTON EastlWest Street: SR-900 North/South Street: 148THAVE SE Intersection Orientation: East-West Studv Period (hrs): 0.25 Vehicle Volumes and Adjustments Major Street Eastbound Westbound Movement 1 2 3 4 5 6 L T R L T R Volume 35 393 64 4 509 12 Peak-Hour Factor, PHF 0.90 0.90 0.90 . 0.90 0.90 0.90 Hourly Flow Rate, HFR 38 436 71 4 565 13 Percent Heavy Vehicles a ----a ---- Median Type Undivided RT Channelized a a Lanes a 1 a a 1 0 Configuration LTR LTR Upstream Signal a a Minor Street Northbound Southbound Movement 7 8 9 10 11 12 L T R L T R Volume 38 31 25 14 63 27 Peak-Hour Factor, PHF 0.80 0.80 0.80 0.80 0.80 0.80 Hourly Flow Rate, HFR 47 38 31 17 78 33 Percent Heavy Vehicles a a a a a a Percent Grade (%) a a Flared Approach N N Storage a a AT Channelized a a Lanes 0 t. a a 1 0 ConfigUration . LTR LTR Delay, Queue Length, and Level of Service pproach EB WB Northbound Southbound Movement 1 4 7 8 9 10 ,1 12 Lane Configuration LTR LTR LTR LTR (vph) 38 4 116 128 C (m)(vph) 1006 1068 162 209 vic 0.04 0.00 0.72 0.61 95% queue length 0.12' 0.01 4.32 3.52 Control Delay 8.7 8.4 69.4 46.2 LOS A A F E -"pproach Delay -----69.4 46.2 Approach LOS ----F E HCS2000™ Copyright © 2000 University of Florida, All Rights Reserved Version 4.1 TWO-WAY STOP CONTROL SUMMARY , General Information Site Information Analyst JMS Intersection SR-900/148TH AVE SE Agency/Co. GSA urisdiction K/NG COUNTY Date Performed 10-01-01 (Collected 9-26-0 I) Analysis Year 2005 WITHOUT PROJECT IAnal'Lsis Time Period PM PEAK Project ID EAST RENTON East/West Street: SR-900 North/South Street: 148THAVE SE Intersection Orientation: East-West Study Period (hrs : 0.25 Vehicle Volumes and Ad'ustments Major Street Eastbound Westbound Movement 1 2 3 4 5 6 L T R L T R Volume 58 435 98 11 563 15 Peak-Hour Factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 Hourly Flow Rate, HFR 64 483 108 12 625 16 Percent Heavy Vehicles 0 ----0 ---- Median Type Undivided RT Channelized 0 0 Lanes 0 1 0 0 1 0 Configuration LTR LTR Upstream Si~nal 0 0 Minor Street Northbound Southbound Movement 7 8 9 10 11 12 L T R L T R Volume 56 51 35 18 97 38 Peak-Hour Factor, PHF 0.80 0.80 0.80 0.80 0.80 0.80 Hourly Flow Rate, HFR 69 63 43 22 121 47 Percent Heavy Vehicles 0 0 0 0 0 0 Percent Grade (%) 0 0 Flared Approach N N Storage 0 0 RT Channelized 0 0 Lanes 0 1 0 0 1 0 Configuration Lm LTR Delay, Queue Length, and Level of Service pproach EB WB Northbound Southbound Movement 1 4 7 8 9 10 1.1 12 Lane Configu ration LTR LTR LTR LTR (vph) 64 12 175 190 C (m) (vph) 953 995 , 36 139 fI/c 0.07 0.01 4.86 1.37 95% queue length 0.22 0.04 20.57 12.21 Control Delay 9.0 8.7 264.3 LOS A A F F Approach Delay ----264.3 Approach LOS ----F F HCS2000Thi Copynght © 2000 University of Florida, All Rights Reserved Version 4.1 ._----.. ----r •• ___ , -.I-I TWO-WAY STOP CONTROL SUMMARY General Information Site Information [Analyst JMS Intersection SR-9001148TH A VE SE V\gency/Co. GSA ~urisdiction KING COUNTY Date Performed 10-01-01 (Collected 9-26-01) V\nalysis Year 2005 WITH PROJECT V\nalysis Time Period PM PEAK Project 10 EAST RENTON East/West Street: SR-900 NorthlSouth Street: 148THAVE SE Intersection Orientation: East-West Study Period (hrs): 0.25 Vehicle Volumes and Adjustments Major Street Eastbound Westbound Movement -1 2 3 4 5 6 L T R L T R Volume 58 435 107 14 563 15 Peak-Hour Factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 Hourly Flow Rate, HFR 64 483 118 15 625 16 Percent Heavy Vehicles 0 ----0 ---- Median Type Undivided RT Channelized 0 0 Lanes 0 1 0 0 1 0 Configuration LTR LTR Upstream Signal 0 0 Minor Street Northbound Southbound Movement 7 8 9 10 11 12 L T R L T R Volume 61 59 37 18 111 38 Peak-Hour Factor, PHF 0.80 . 0.80 0.80 0.80 0.80 0.80 Hourly Flow Rate, HFR 76 73 46 22 138 47 . Percent Heavy Vehicles 0 0 0 0 0 0 Percent Grade (%) 0 0 Flared Approach N N Storage 0 0 RT Channelized 0 0 Lanes 0 1 0 0 1 0 Configuration LTR· LTR Delay, Queue Length, and Level of Service lApp roach EB WB Northbound Southbound Movement 1 4 7 8 9 10 11. 12 Lane Configuration LTR' LTR LTR LTR r.-(vph) 64 15 195 207 C (m) (vph) 953 986 0 130 vic 0.07 0.02 1.59 95% queue length 0.22 0.05 14.85 Control Delay 9.0 8.7 359.9 LOS A A F F pproach Delay ----359.9 lApp roach LOS ----F HCS2000™ Copynght © 2000 University of Flonda, All Right;; Reserved Version 4.1 ----... _. ----.--.-.------'----r , , Lqnes, Volumes, Timings 3: SR-900 & 148th Ave SE (2005 WITH PROJECT) - Baseline Garrysbell-st51 t PM PEAK 10/12/2001 ._ i Synchro 5 Report Page 1 lanes, Volumes, Timings , , 3: SR-900 & 148th Ave SE (2005 WITH PROJECT) Intersection Summary and Phases: -- Baseline Garrysbeli-st51 PM PEAK 10/12/2001 Synchro 5 Report Page 2 ' .. . HCM Unsignalized Intersection Capacity Analysis 3:'SR-900 & 148th Ave SE (2005 WITHOUT PROJECT) t PM PEAK. 1/2/2002 ~Qv'~rn§~1!i~!jl!;,1iB913lfBE~!illill!~Ml6lJ.9tBJT_$.ffi.m~gllljBJiIl!j"l.!iilE?!il."$BJ,.ifi~~~ Lane Configurations 4> 4>'. 4> 4> §j9fi~2IDl~g$r1~J$l~~Jlfu1&i'ie'{'~JflttJW1;'tII1.\!l)lIjISJo.~L¥~,~~~WR';"":;L"",;1f,I"". ~"".;il Grade 0% 0% 0% 0% ;~,.'~!i1N[f;W~M)l!l;:~!I!~~~5~}IJi!§1li'Jl1~$63If~:I11tjll!l§§'9g~JlMN§l1~filtll\'is.:;;Bi§,§ Peak Hour Factor 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 f.i~l1lJ!Y!lffll!:§Jm(Qepttl)!Jlllti.m~~~~mJf!$l1'~1I~i:'~~H~m?I'glllgQ!0'!lJ851.f1~ Pedestrians ll?iti[tjtjiitIDU!fa(iiet~.Iii~~M!il~1~;j4!iJt!I~W'!,&§!jl~1'~~~\i8:~@a!w.;£i:l;lm;:l:a$lltl'!!'!!!I!lI~~ Volume Total 642 640 154 166 . ·.L. ~,). !.f . ~. .~: ifJiifff, .. ~ 1'\;t,! ir":J.(;;';;fj;'Y~ Baseline Garrysbell-st51 ,'. "' Synchro 5 Report Page 1 , , f",CM Unsignalized Intersection Capacity Analysis 6: 'SE 116th St & 148th Ave SE (2001 EXISTING) -+ t PM PEAK 10/12/2001 M5XfAfu§Q~~~B.I\fI!I3!3_!;!llBrll~!3.l1~ll'lteif~vA\1IRIBI!ilJ\lElIL_B.;r_!'l!lljjD'£.lil~lIik~$.Iil_!;ililg Lane Configurations 4> 4> 4> 4> §Jgmr~tJrQ]_~~~l£k~tqp1tim!1~w~~§.1i~i!ll~g~;~§t.@t!iz&~\~s~~~jZFiil~ Grade 0% 0% 0% 0% I{lv(ffli(~nl'l:ill'iiBm~L~J11Ii~kirl.?,)1j;Jj'j!3!jj,f~~~·rmf!!~/':E.'.'i!d~§?iL'!'tj!:g~B Peak Hour Factor 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 !.l!li!¥!JYj!1~!'.1!rig{~"\!iMi4if~5a1i.1,;iIft,~!iii'ii2idii~4:R~~;iJSj.i1M£E~fuKt:t:l.~1~.:J3J,.~1~f1a3»~!i:'ii@1<l Pedestrians Baseline Garrysbell·st51 Synchro 5 Report Page 1 HCM Unsignalized Iniersection Capacity Analysis , . 6: 'SE 116th St & 148th Ave SE (2005 WITHOUT PROJECT) t Baseline Garrysbell-st51 PM PEAK 10/12/2001 ., ,~ .17, , ,) i " Synchro 5 Report Page 1 • I HCM Unsignalized Intersection Capacity Analysis 6: BE 116th St & 148th Ave SE (2005 WITH PROJECT) I 15 18 t PM PEAK 10/12/2001 ~.qli.lt¥i~~~~!tJJI!j?jilfi!!1i£;lilM~18'tli'!!:"l8j1Nj!JlriiItJI!/ifffi$Iii!l1l,!I,t,!ry;ii!fi,Jit\"l,;&!'iititfi:.;l;£l,IJl,,'@;4\J\::f~:E!iJ, cSH 552637 1335 1416 , 'iii:. i1;::ii'i!' :!dti*~~ittt<~Ii!I~qj]jjJ,j;~I¥*s.IiiWJta~,t'1l:~!'I!!,j;;)if':'!I',~fi"Jl'!,~,¢~I\fJi~W,Upilllliill!Jii4!'.t;l'l' •• Average Delay. 1:4 JffiteIs§GtlQ~l@~Ra6Hy~I~,tilizaUqH~~m~~i~~!@[~BE~~!!t"~~d_::·,N-*t,~~~ru;,~'ft~::l;:;Ji ~,!;}j Baseline Garrysbell-st51 . ", .,." Synchro 5 Report Page 1 .------------.. _---------------------------------, , . I,CM Unsignalized Intersection Capacity Analysis 9:'Site Access & 148th Ave SE (2005 WITH PROJECT) Baseline Garrysbell-st51 PM PEAK. 10/12/2001 Synchro 5 Report Page 1 .. " , , '. , '.~ I I I I , I I I I .. I I -= .. ··l I I I I I I , Age • · . • , , , .' 14,t== ." , " " -·'il: Py AkF " : . " -... EvB ':::;.:;~~~,~~;;/~~ "' Age ~--::: Ag~ 1 GUIDE TO MAPPING UNITS j for a .full description of a mapping unit, read both the description of the mapping unit and that of the soil series to which the mapping unit belongs. See table·6, page 70, for descriptions of woodland groups. Other I infonnation is given in .tables as follows: I Acreage and extent, table 1. page 9. Engineering uses of the soils, tables 2 and 3, pages 36 through 55. Town and country planning, table 4, page Recreational uses, table 5, page 64. Estimated yields. table 7, page 79. 57. I~:ol Mapping unit Described on page l"AgB_Alderwood gravelly sandy loam, 0 to 6 percent.slopes---------- If&c..-Alderwood gravelly sandy loam, 6 to )5 percent slopes--------- gD Alderwood gravelly sandy loam, 15 to 30 percent slopes-------- · F Alderwood and Xitsap soils, very steep------------------------ I AmB Arents. Alderwood material, 0 to 6 percent slopes ij---------:-- ArnC Arents, Alderwood material, 6 to IS percent slopes 1/--------- t A.rents, EVerett material y-------------:-----------~--------- C Beausite gravelly sandy loam. 6 to 15 percent slopes---------- i eD Beausite gravelly sandy loam, IS to 30 percent slopes--------- BeF Beausite gravelly sandy loam. 40 to 7S .percent s)opes--------- I h Bellingham silt loam------------------------------------------ • uT Briscot silt loam--------------------------------------------- Buckley silt loam----------------------------------~--------- '(b Coas tal be ache s----------------------------------------------- ·fu i EvC EvD 'r c ; InA InC 'I"'') : .... y ... , KpD .~c eC i g N< ·r .~~ OvC 'E~ PI< :f.c · RaD RdC :ldE I Earlmont si-l t 1 oam----- -------- ------------- --- - - ------------- Edgewick fine sandy loam-------------------------------------- Everett gravelly sandy loam, 0 to 5 percent slopes------------ Everett gravelly sandy loam, S to IS peTcent slopes----------- Everett gravelly sandy loam. 15 to 30 percent slopes---------- 'Everett-Alderwood gravelly sandy loarns. 6 to IS percent slopes------------------------------------------------------ Indianola loamy fine sand, 0 to 4 percent slopes-------------- Indianola loamy fine sand. 4 to 15 percent slopes.------------- Indianola loamy fine sand, 15 to 30 percent slopes------------ Kitsap silt loam, 2 to 8 percent slopes----------------------- Kitsap silt loam, 8 to 15 percent slopes---------------------- Kitsap silt loam, IS to 30 percent slopes--------------------- Klaus gravelly loamy sand, 6 to 15 percent slopes------------- Mixed alluvial land------------------------------------------- Neilton very gravelly loamy sand. 2 to 15 percent slopes------ Newberg silt loam--------------------------------------------- Nooks ack 5i 1 t loam----------.---------------------------------- Norma sandy· loam---------------------------------------------- Orcas peat---------------------------------------------------- Oridia silt loam---------------------------------------------- Ovall gravelly loam t 0 to 15 percent slopes------------------- Oval 1 gravelly loam, 15 to 25 percent slopes------------------ Ovall gravelly loam, 40 to 75 percent slopes------------------ Pilchuck loamy fine sand-------------------------------------- Pil chuck fi ne sandy loam------- - ------------------------------ Puget silty clay loam----------------------------------------- Puyallup fine sandy loam-------------------------------------- Ragnar fine sandy loam, 6 to 15 percent slopes---------------- Ragnar fine sandy loam, IS to 2S percent slopes--------------- Ragnar-Indianola association~ sloping: 1/---------------------- Ragnar·soiI-----------------------~--------------------- Indianola soil------------------------------------------- Ragnar-Indianola association~ moderately steep: 1/------------ Ragnar soil--------------------------------~------------ Indianola soil------------------------------------------- 10 8 10 10 10 10 II II 12 12 12 13 13 14 14 15 15 16 16 16 17 16 17 17 18 18 .18 18 19 19 20 20 21 21 22 23 23 23 23 24 24 25 26 26 26 Woodland Capability unit group Synbol Page Syoool IVe-2 76 3d2 IVe-2 76 3dl Vle-2 78 3dl VIIe-l 7B 2dl IVe-2 76 3d2 IVe-2 76 3d2 IV5-1 77 3£3 IVe-2 76 3d2 Vle-l 78 3dl VII e-I 78 3dl I1lw-2 76 3w2 Ilw-2 75 3wl Hlw-2 76 4wl VIIlw-1 78 Ilw-2 75 3w2 IIlw-l 75 201 IV5-1 77 3f3 V15-1 78 3£3 Vle-l 77 3f2 Vls-l 78 3£3 IVs-2 77 453 IVs-2 77 453 Vle-} 76 452 IIIe-l 75 2d2 IVe-l 76 ?d2 Vle-2 78 ldl VIs-! 78 3fi V]w-Z 78 201 Vls-l 78 3£3 11w-l 74 201 I1w-) 74 201 Il Iw-3 76 3w2 VIIIw-l 78 IIw-Z 7S 3w1 IVe-2 76 3dl Vle-2 78 3dl VIIe-1 78 3dl VJw-l 78 l51 IVw-l 76 251 1I1w-2 76 3w2 IIw-1 74 201 IVe-3 77 451 Vle-2 78 451 -------- IVe-3 77 451 IV5-2 77 453 -------- Vle-2 78 451 Vle-I 77 452 U. S. GOVERNMENT PRINTING OFFICE: 1973 0 -468_266 rJ II I. II , . '- I , -J J I I I I 'J ;1 'I j 3.2.2 KCRTSIRUNOFF FILES METHOD-GENERATING TIME SERIES TABLE 3.2.2.B EQillVALENCE BEnVEEN SCS SOIL TYPES AND KCRTS SOIL TYPES SCS Soil Type SCS KCRTS Soil Notes Hydrologic Group Soil Group Alderwood (AgB, AgC, AgD) C Till Arents, Alderwood Material (AmB, AmC) C Till Arents, Everett Material (An) B Outwash 1 Beausite (BeC, BeD, Be F) C Till 2 Bellingham (Bh) D Till 3 Briscot (Br) D Till 3 Buckley (Bu) D Till 4 Earlmont (Ea) 0 Till 3 Edgewick (Ed) C Till 3 Everett (EvB, EvC, EvD, EwC) NB Outwash 1 Indianola (InC, InA, InD) A Outwash 1 Kitsap (KpB, KpC, KpD) C Till Klaus (KsC) C Outwash 1 Neilton (NeC) A Outwash 1 Newberg (Ng) B Till 3 Nooksack (Nk) C Till 3 Norma (No) 0 Till 3 Orcas (Or) D Wetland Oridia (Os) D Till 3 Ovall (OvC, OvD, OvF) C Till 2 Pilchuck (Pc) C Till 3 Puget (Pu) 0 Till 3 Puyallup (Py) B Till 3 Ragnar (RaC, RaD, RaC, RaE) B Outwash 1 Renton (Re) 0 Till 3 Salal (Sa) C Till 3 Sammamish (Sh) D Till 3 Seattle (Sk) D Wetland Shalcar (Sm) D Till 3 Si (Sn) C Till 3 Snohomish (So, Sr) D Till 3 Sultan (Su) C Till 3 Tukwila (Tu) 0 Till 3 Woodinville (Wo) 0 Till 3 Notes: 1. Where outwash soils are saturated or underlain at shallow depth «5 feet) by glacial till, they should be treated as till soils. 2. These are bedrock soils. but calibration of HSPF by King County DNR shows bedrock soils to have similar hydrologic response to till soils. 3. These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water table. In the absence of detailed study, these soils should be treated as till soils. 4. Buckley soils are formed on the low·permeability Osceola mudflow. Hydrologic response is assumed to be similar to that of till soils, 1998 Surface Waler Design Manual 911198 3·25 - , , .'-r." ," I , i, ~ I, .... ,.! :" 1<., ': ;'j " .1 .. :n ,,' Jl I -, I:· ... ";. , , .. -". 11' ," i I , " \ \ ~ I " ",. , " ) ~~ n i , \ I, - - " " .. Jj/ ", f ' ... " .,' " "I;'" .:.:. ··.·to .•. .', I )J.' " \ ii, :: . ,1 . ;:'1 ":'\" Z;,'" i ';, -,.,' , " ;;0',:.- ;:tl, !l \: "I .. ..,.~ t I ~', ~;' !' i •• ..i) .. ,' .. Jt< ..... /' ' .i "~.,,,. " • ,j I, I' .: ... ;,: II' " , , 1'- I' .: t " , , " 11; i, 'j! I' " 'z " 'I) ;, i_' t en l' ,'W :~~,,'iJ "', , 'Ii' . ~ ... ','I , .. .,., " .~ " ', .. ,,1 \ '~,,' "'". (!JH :""~ Il. ----'--- CIJ Z -~ = N W i ~ ,-Z I-. -~ Q I. s- '''t'' :j \- " 1 " i!' = i!' ~ ~ <" <Il H c:: " ::I c:: is: s ::I .» S ,.'" ~ . c: gj ~ c:: ~ U; ~~ ... ><.2 0 .6 "0 'iij' 8 ... ::I -It :E rJ) h I ~---'-" ~I . '. \ . ,·jf 1'1' I ? " i,n .... ~\ I if i . \, . ',' ,(t' i .... ... ". ... .;.~ II .. .. I I : ~ ~ .. ~ .. '" • .. " ~ 0 " , I, '" ,; " 1 ! . ./ '/ I.~ .t'l , , . ' - ---- - ---~ ,-- - - ---- - .-.-... .-.- , .." ! "'-...J" , ri ! ! IIII ... :.. :.. .. .. .. ~- I I . I , , I I . I I. I •• I !. I I. I I I I I I I I I I I I····· 1/2 0 1 I ... The boundaries of the sensitive <HeiliS dis- played on these maps are approximate. Additional sensitive ilITeiliS that have not been mapped may be present on a devel. MilE N ~~~~n~et:~~nOS!lha~il:. i1~~~ritegi~~r~~;:! m~~s_a-'J<LLt)c..sIte.condillO.u._t.he-a.clual.p~ __ , _____ " -----------, :--~----------~--·--·--------------·----sence or absence on the site of the sensitive area -as defined in the Sensitive Area Ordinance -is the legal control. Erosion Hazard Areas -- Issaquah :!:'" 9 -. -. -. -. -. -. -. -. -. -. -. - - -- I .J If"J •~:":":coP ,... ..... ~ ~ I -- I I ! ·wl ~I o I i I I I I I I , r ! ! I -= : ... .-.-.-.-.-.-.-.-.- , . , ;: .-.-.-.- I I I , I I : ~- i I I ~ o _ - --- - --- - - -- - - -- - -- -I ! , I I. -. _.--------- ----... -.. - Basin: Cedar River Symbol Drainage Component Type Name,Size Type: sheet, swale, see map stream, channel, pipe, pond; Size: diameter, surface area C1 Honey Dew (Honey) Creek C2 $eetflow 0 Honey Dew (Honey) Creek E 24" CMP Culvert F-G Honey Dew (Honey) Creek OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Subbasin Name: May Creek Drainage Component Slope Distance Existing Potential Description from site Problems Problems discharge <XlIlStrictions, under· capacity, pondlng drainage basin, vegetation, % 114 mi = 1320 It overtopping, flooding,habltat or. organism cover, depth, type of sensitive destruction, scouring, bank sloughing, area, volume sedimentation, incision, other erosion 3-4' wide drainage"channel 0.5% 10 It None None pasture 5-15% .14 mile none none 3-4' wide drainage channel 0.5% 480 ft None None 2·3' of cover under driveway 0.5% 500 ft None None 3-12' wide drainage channel 0.5% 500 -2000 It None None Triad Associates Subbasin Number: Observations cif field inspector resource reviewer, or resident tributa!)' area, likelihood of problem, overflow pathways, potential impacts. unobstructed natural and man altered drainage channel erosion unobstructed natural and man altered drainage channel if culvert overflows. it will cause no damage to private structures broad drainage dlannel with heavy vegetation on both sides of channel -- ... - -- --- --- - - ---RENTON -.--E~ IO-23-~ . - -ou- ~.ml' c-=:-==.: -. =t;l,.;r-'-'-~ '-';-1': '-'~'. :-:::-:.'';' ?~ . --'--... ---------- 18J.1 J ® "13 John' Hansen 286 Ac. Wm E. Broyles 191 Ac. George C Davi s 2.18AC. 112UI Aclke Hayer 2.~)~ Ac. /l1J[] Franc',s p. Brown 4.77 Ac. Floyd w. Shaff. e1' ux 4.14 Ac. O. ~l3A c. Citi zen Fed. S8. l. 12 ) S.P.688009 . ® @Jol stan le~ J. Petersen 'II "-@ I .... --.-------i~\ J- 1/4? EJ 4.% Ac. B'J S.P. 88200; R ~ e 4J :c (j') Henry lJro 4.77 Ac. "Imi 116 8 ~ ~ '" " ~ ® Robert L. Starzman <.SOAc. ::: Theodore l. Binder ::: II, )00" ---, S.34 Ac. IIaE] (I) ;llhr-------~ ,:,1. ",' ',:-: ... SP 778111 12) ";.1 III---",vo.,,'" ... !..... "'0.":" ? . ;. JI I.,' . ',:. + ® @) [ ~ ~ '1\ 67 Ac. ~ . Ac. " :: ~ crnr ~ ... Lionel Lesh \ ~ ~'j • @> ". 1 @i J too '" J ~nLr+e A. [)eckstrom II) C1 CMP CUl.VERT , B1'" . ",1 .. , . .. !:'_~:,-! i . ," ..... -.0 5 Ac. E (I (3J3 \~. '-'-' ."'.fJ • vrl< John M. Pollock Fi rst Sav.8. loa n Assn. 4.70 Ac E.3U\4 s -----..---.--.. ~ ... - 24" CMP CULVERT ~ :0 <.i/' ~ o ~. g ~ GJ,t C2 ............. . ..-~ .. 12" CMP CULVERT ~ .. ®) 1\1 .. ...... :.,. :1 :s MCl. :;:[ k 18 4-JO@ '65 N 1 .-. .I -~;----....... ~.' .. "'~ "'~ .. \c. 1"=200' 1'20[4 qJ4 Ac. . e I (has. H. Moo"e 3.85 Ac. O.4S Ac. @ ~ ~ i@ .::1 Oonald R. Lamen ! i I'/!;!(' I ' : , . ; J !I ' ! I j i I i I! Ii Iii 1,\ If:1 I I· I I , 4.50 Ac. \!;>.nc,. W (i,'ihhl~ ,.t '" ? ,q Ar ~I::; Henry W Owens 3.93 Ac. @loll DOWNSTREAM DRAINAGE EXHIBIT L.:!:!!J ...... ~:. o ~z.' ~ ~ 0) I 'j I Map Output Page 1 of 1 I ®KingCoUnty~~ Comments I I I I I I • •. : .: " . -' I I III The Buffer /'-/ Legend """ • II Buffemd Selection 0 Parcels 0-County Boundary 0 Lakes and lal'gQ RMUS .1. H-.le. ~ct6~\JS , _0 Streets ;./ Stteams I ~ H#M1rt' II WlRO DrIIinage Complaints -= I-I sources i I makes no representations or warranties, express or i ,as 10 accuracy, completeness, timeliness, or rights 10 the use of such Infn;,';;,",n, King County shaH not be Hable for any general, special, Indirect, incidental, or consequential damages including, but not limited 10, or lost profits I from the use or misuse of the information contained on this map. Any sale of this map or information on I By visiting this and other King conditions of the site. The details. I I I http://www5.l11etrokc.gov/servlet/com.esri.esrimap.Esrimap?ServiceName=overview&Clie...11/4/2004 I Map Output Page 1 of 1 I ®King COUnty --__ I I I I I I I I I I I 0_ County Bcundaty 0 Legend , _0 P;aroel$ S""OI$ Ell Incorpomted Ama ~ u~ 0 Lakes; and Latge rovers --IV Stre~ms ./1..:' ""'" III WlRO Dr.inage Complaints I to accuracy. completeness, timeliness, or rights to the use of such County shall not be liable for any general, special, incidental, or consequential damages including, but nollimited to, I from the use or misuse of the information contained on this map. Any sale of this map or information on By visiting this and other King conditions afthe site. The details-,- I I I I I I I I I I I I I I I I Camwest -E.Renton Drainage Complaints I Complaint I. No Status Problem 11995-0009 CLOSED EROSION ! 11996-0185 CLOSED FLOG i 11996-0552 CLOSED FLDG i [1996-0552 CLOSED FLDG i 11989-0776 CLOSED FLDG Type C C C R C 11999-0151 CLOSED DRAINAGE C I , , i Ree Date Thu. 5 Jan 1995 00:00:00 Thu. 8 Feb 199600:00:00 Fri. 23 Feb 1996 00:00:00 Thu. 14 Mar 1996 00:00:00 Mon, 4 Dec 1989 00:00:00 Mon. 22 Feb 1999 00:00:00 TB PADD PADDI PADD SUF 35E4 14701 116TH ST 35D4 11625 148TH AVE SE 35D3 11615 148TH AVE SE 35D3 11615 148TH AVE SE 35D4 11644 142NDAVE SE 35D4 11624 142NDAVE SE PADD Complaint Status Problem Type Rae Date TB PADD PADD 1 No SUF 1988-0790 CLOSED DRNG C Fri. 23 Dec 1988 35D3 14418 116TH ST 00:00:00 1989-0140 CLOSED EROSION C Tue. 14 Mar 1989 35D3 14429 116TH ST 00:00:00 1989-0150 CLOSED DRNG/ERO C Wed, 15 Mar 1989 35D3 14428 116TH ST , I 00:00:00 1994-1000 CLOSED FLOODING C Thu, 29 Dec 1994 35E4 11615 148TH AVE SE 00:00:00 11994-1000 CLOSED FLOODING NDA Wed, 22 Mar 1995 35E4 11615 148TH AVE SE 00:00:00 11994-1000 CLOSED FLOODING RN Tue.10Jan 1995 35E4 11615 148THAVE SE PIN NTB 1023059357 627A7 1023059354 626J7 1023059353 626J6 1023059353 626J6 1023059060 626J7 1023059092 626J7 PIN NTB 1023059362 626J6 1023059004 626J6 1023059363 626J6 1023059390 627A7 1023059390 627A7 1023059390 627A7 L ___ ... __ . ___ ._._. ___ . ______ . ___ ~~~O.O~~_ ..• ___ ..•. _._. ___________ '""--.--"--'.-.--~-.-.---.. -----.-.- I I I I I '1' .c-, .. '-.... _---.-.... --.. __ ._---_._'--'-'--_.--.. _. , 'P.4/212l ,$ .1 • Type_.;;....(!,_ RBce/V9d by. , I. Date; /.,? ¢. OK'd by: RecBlved from: (Ploase prlnt plainly for scanning). (Day) (EVa) PHONE ££5-f7.f> S~ __ _ City 49:(7 uw State Zip r~o~ 1 I 1 I' .'atname: Lher agencies Involved; r~n'lir·'. i I 'l!&...~~~ 1 1/4 S T R " Parcel No. I0.25aS" "lU.3 .. Lot No: Blook No; No Fleld Investigatlon NeEoded ~-:--_ KroII __ _ Tlt.Bros; New 6"2. 7 IJ 7 Old 5S£<!\ Basin iJtHr CouncD Dist Charge No: ~--~==~~==~-~~====----~--~.--l~sPoNSE: Citizen notified on 1-1(..t1;S'by .k phone _ letter· _In person '. ~ jl4s ~~e;-*s ,',./W_ #..50 ~U 90-1 ~ fL.-/l.Jf);f ~ 4,.. ~~.,(:.y. . "")L bJ--. ,~ rsmoN< ......... 1JL., Nl-'15 by.:1t1 _ Lead agency has been notmed: r-Problem has been corrected. -_-rrNo~pro=bI":':em~has"""""b~ee":':n:-:17de"""nt""'lfi;-:ed-:;".-----:p""rI""'o""'r l""nv""est~lga""t"'lo""n-:-a-'-dd~re""'ss""'e=s-::p~ro'blem: -SoeFilo# .' Private problem .. NDAP will not consider because: -..:..-Water originates onslte and/or on neighbOring parcel 1 -Location Is ou:tslde SWM Servloe Araa. DAlE CLOSED; 3..:..J '2-.t..I...!15:. by: m... l)llM .. c.... '. OR: No further action recommended because: ..... Other (Specify): .----------.... -.. ----... -----.. ---'--.. -~ .. ----_ .. _---------------... _ ..... _---------_ .... -. NOV. 8.2004 10:33RM KC WLRD I" , . --.-,.-~ ........... I KlNG COUNTY SURFACE WATGR MANAGEMENT DIVISION DRAINAGE INVESTIGA.TION'REPORT Page 2: FIELD INVESTIGAnO~ LLAINT #94-1000 METZGER Cgated 1-6-!lS by Doug DobIdlls with Mrs. Metzger oDBite to discuss her drainage con=s that flooded the ~ent other house, NO. 339 P.S/20 'lbe basemeDt \\'lIS fioodcd and damaged three fOOIIIS and a bathIooIn, Metzger lives below road grade and recleves water from 148th ave Eaod also a ditch to the north other proper1f that is almed right at her house. She has a small yard drain In the DOrteast cotIler other lot tries to hand1ethls t1ow1t lIPpe31'S the small yard drain couldn't bandlethe jJow ofwatm' and overtopped'andfiooded thebasemcnt. roadside ditch has water contribUted by 1hree properties to the north of Metzger that dtaios Into this ditch. Mrs. M;etzger WDIIlS to \mow tho is responsible for 1his dtainage and who ~ fix the ~roblenl" I I I ketch: I I I I .. " - I -_____ '__lnvestI~~_~y __ ,o....,..,_-__.,_"'="' ......... =.,.,..'"'==__Date,=~---- •. NO~: B.21211214 1121:33AM KC WLRD .--_. I .... NI)AP PR:IOR:t'tY SCORXNG" I . PrO)'eot . • j " . .' .. ,,',," . . "". -I...... :.' . .' . NalIIe: kiw. 41e..+z~Q'e Project NUlIIber: ,.' , ., -'_.. ..... " . ", I " " ' . ~ I' 'I,. I' I I I I I I I I I I I "'·*"'******·.t .... *************IMPACT CRITERIA**************************. POINTS-ADD 0,2 i!PB012ID!.UiS FUT. ID:~K ~MPACT OR 4 FOR SEVERITY J;MPa.miD (±O,2 OR 4) . , , Livi~q stpuctur~" ~) -I-....a... finl.shed floor (20 + X + co ACCeSS (8 + -) X + ... -- septic/Well (8 + ~) X + .. 0 -Other struoture 'or (4 + -) X + '. = 0 crawlspace - Landscapinq/yard/' (1' ± .JL) X .-Z. + -A.. , .. ,2 parlting Other property I (.5 + ....Q.:.) X -'L + JL = 0 drainage systelll 6 Natural resource :3 ± .,+ .. , ' mrol'AL = .tr<~ ,*"'*******************EVENT FREQUENCY FACTOR************************ Chronio (1+ times/year) ••••• 20 2-5 years; indefinite but ' o,ftenT channel erosion •••• 10 5-10 years ................ ,. .... ,.. 5 1.0-25 years ......... , .. ,. ......... . 2 E.]!'.]!'. = . 10 SUBTOTAL X E. F. F. ..'~ ADD 20 POINTS IF IN A TARGETED BASIN + _.-O~ Jlt"t-f >25 years.................... 1 TOTAL :tHPACT SCOM == Pate: 30« Jf'S: Rated by A C'M ' I .,. ,. *·*.*****.***************"'COST-l3ENEFIT RATIO***"'*******************. , 'COST OF ~OLUTION = $ l~ ~}'O /. '1'1' AM TOTAL IMPACT SCORE X 100 I COST = NPAP PRIORITY SCORE == /. 91$ Date: Rated by AEM • * Note: 5pa~e from storms < 10 years receives Yes. I -_c ..... _. -._-.-..... --.... -.--------.. -...... -. ----"'-.-.. , --":;'.:"':;~:-:. c:--.,-=~. I I I I I I I I I I I I I I I I --r·---II . ;1--! _t:l~: 3~9 . __ .Pj:.7 ~20 .' . ... " '" NEIGHBORHOOD Dl\AINAGllI ABSI·STANOl!: PROGRAM COMPLAINT 1lVAL0000'rtCJlll HEKO DA!rlil1 3-15-95 '\' , !rO. RANDY SNOW FROM. AlAN MEYli:RS p. NI!AP El7AL!JATION FOR CO!:!PLAINT NO. 94-1000 KIM METZGER BACKGBOtlND! The original complaint was called in on 12-29-94 and Doug D. completed the initial field investigation on 1-6-95. Randy Snow and I spoke to both MBs. KetzgBr and Sc~oeder during oue field evaluation ~n 3-6-95 on Surface water from streBte, pastures and ~ds north and east of Metzger's property which accumulate and flow into a veey narrow drainage ditch within the 148th Avenue SE R/W flowing south along ths west Bide of 148th into the NE corner of MBtzger's yard which is a low point helow -road grade in this neighboehood hasin. The flow partially drains into a private 08 at the NB corner of her yard which conveys eame water t~ugh an 8 inch buriad OPP pipe west aropnd the ncrth sids of her house and diecharg-es west into the S,,~eder-'s horsB pasture(see ccmplaint 95- 0009) approximately 6 feet lower than KatzgBr'e back yard level. A SMall pond forme at the Nl!I comer cf J4etzger' a yard and during recent heavy runoff flooded into her huaa.ent filling seve",al bedroOOlls and a bathroom, 4a11\ag:Lng fw:niture, carpets and walls. ~he schroeder' .. complaint includes reported erosion, sed~ntation, and ~ncreaBed minor flooding aoross thelr large eloping hcree yard/paBture frOID HE to sw towudB a lOW wooded area which develope into the uppe~ channel of Boney creek which is teibutary of May Creek. For this report, the ho~se pasture area impacts are oonsidered to impact a hO"'ee boarding commercial husiness, FINDINGS; since the problem meets all of the NDAP project criteria lillted J:>e1ow, it ~alifiee for and has been investigated under the NDAP program. • • • • !rhe problem Bite ia within the SWK se~viae area and does not involve a King county (KC) code violation. !!!he prohlem aite Shows evidenoe of or reported 100a1ized flood:l.nq, eroeion and/or sedLmentation within the off road drainage system on private residential and/or commercial prcperty due to latee upstream development (Property othe~ than KC or State roads, parka or schools), !rhe problem is caused by eurface water (not groundwater) frOID more than one adjOining property and createe impacts beyond the property owners' control. If there La only one affected property, that property . contributes lese tiban 15' of the proble~ runoff. ~hia project baa top pr:l.ority rating under ths xnAP beoause floo4:i.Dg of liVing apace ha.. occurred fro. a ato¥a judged to be leB8 than a 10 year .torm event. PAGE 1 OF 3 1------------~ "----"."-~---------------~-------~----~,---~. I·· I .... I~ I I I I I I I I I I I I I I I I I NOV. 8.2004 10:34AM KC WLRD NO. 339 P.8/2121 ( a OPTIONS AND DISQUSSION Options considered to convey the excess surface etorm water past both properties include the following. '\ ' 1. Install an underground 12 inch storm drain system from the NE corner of the Metzger's yard near the existing CB, west approximately 130 lineal feet to just inside the Sohroeder's property line, two ~e 1 CBs woul<t be installed, one at each end of this 12 pipe. From the outlet of the second CB to ba located near the NE corner of the Schroeder's horse yard on the south aide of the CB, a sCOur protection rip rap outlet would oonvey the storm water safely into a grasBed earthen swale about e feet wide which would run approximately 175 feet . south along the Schroeder'e east property line where it would discharge into an existing ditoh 1ina flowing east to west down into what appears to be a natural drainage channel whiCh flows west-northwsst, This storm water swale would include a scour ~otection structure/facility located at the outlet of the storm drain pipe in the SE corner of the horse yard in order to eafelr'convey the peak flows from the end of the grasBed swa1e into the ex sting east-west man~ade ditch • . 2. This option is similar to No. 1 described above. The difference is that the conveyance facility from the NE corner of Metzger's yard west to the schroe~r's NR corner would oonsist of a grase lined swals in place of the 12 inch storm drain pipe. This option would include a U shaped discharge chute ~ade with eeveral rock gab ion/Reno mattreases set on a layer of heavy duty filter fabric located at tha end of the swale at the west side of Metzger's back yard. This chute would provide soil erosional protection where the storm runoff would discharge from the upper swa1e down into the swa1e to be located along the east side of the Schroeder's horse yard. From this point, the storm water would be conveyed south approximately 175 feet as desoribed above in Option No.1. DlPAC!I: BCOIW -220 PBOPQSIt) SOLuTION I Since the safe conveyanoe of the pe" storm runoff through tbe Metzger's yard is of pr.l.lllary ilIIportance, I rac:ommend Option No, 1 be employed to safely convey the peak storm water flows past the Metzger's house. since a grassed swale might erode or wasb out and fail resulting in another basement flooding event, the storm drain facility included in -option No.1 1s preferred based on reliability and safety. However, there is a question whether or not a Type 1 CS and 12 drain pipe would have tbe oapaoity to adequately protect the Metzger's yard and home. A small basin study was o~leted in order to verify the size of storm drain facility required. The results of the study using the aBua computer model were as shown below: Basio Data From Haps and the KeSRN Design Hanual. Basin Area 3.6 Acres 2SYR-24HR Precip. 3.5 Inches Tc 24.0 Minutes Soil TYPe Alderwood Croup C Areas and eNs, pervious Area 75 .. of Area Area in acree eN 2.7 86 PAGI!I 2 OF 3 ImperviOUS 25 0.9 98 Area I ___ ~ _____ '-__ c ____ '---_ -----------------,._, -_., .. _----~"-'-.---.-.. --.-.------'------.------~--.--,._--------. __ .• _._---------_._----,-----_._--- ------------------------------ --------------------------------,---------- NOV. 8.2004 10:34AM KC WLRD NO. 339 P.9/20 I' -.rt-----a---*'----.. -.-.-...... -...... I I I I I I I I I I I I I I I I Rl!SUI.!I!S OF !I!DI!I SBUIl IIInKOD I!ASDr AKlILYSIS POR 25 YEAR S!I!ORM: ...... PEIIX II CPS !I!-PEIIX IIRS VOI.tIMB CF 1.70 7.83 31,065. Baaed on a design peak flow of 1.1 CFS, a 12 inch concrete storm drain pipe at a 2\ slope would have an ample capacity of S.S CFS. However, since the maximum capacity of a noma-r type 1 CB grate inlet equals only about 1 CFS, an expanded grate or cone tYl'e rebar inlet structure would be required along with a below grade rim inlet set in a depression as well as a raised masonry type semi-circle wing wall around the CS inlet to help confina and direot the peak flows down into the OB inlet. A grassed earthen emergenoy overflow swale would also be required to convey peak flows exceeding the design peak flow of 1.7 CFS around the house. this project is estimated to oost approximately $ 11,200. The feasibility of thie project inoludee the follo~ing limitations. 1. The clearance on the north side of the Metzger's house is tight and will probably slow construction work along the north property line. Access to the backyard will require temporarily removing a portion of a 4 foot high fence in two locations for equipment and in~tallation of the storm drain along the north property line. 2. Utility oonfliots along the north property line are unknown except the exieting 6 or 8 inch CPP drain pipe shown on the field investigation report. Other utilities could be in the yard areas? 3. the horse "enaitive owners as Construction in both yards lQay be limited by poor 90ila and yard operations inol~ding breeding/foaling,eeason or other hD~sa iasues. The project muat be coordinated with both required l'RIOIUn" SCORS .. 1.96 PAGE 3 OP 3 I'--C --::..: --_._----------..... -----. --_ ..... -- NO. 339 NOV. 8.20134 10: 34RM !!fO'!!fI'lK~C~W!l!L,!!!R!,!D !'Ii!I!~~!.'!!I~~~":':"~:-:=:::=:::::=::----."'" .. .., .. _. UN1'Y SURFAce WATeR MANAGEMENT DIVISION DRAINAGE INVESTIG.ATION REPORT ), ~e 2; FIELD INVEST1GATIO~ ------~-------------------------------------------------r~U8 of Inv9$fJglltlon: " I COMPLAlNT #95-0009 schroeder lnvestlgated 1.0·95 by Doug Ilobkins Meet with Mrs. Metzger ensile to discuss her drainago IX>lIcetnS that flooded the basement of her house. , I TM basement was flooded and cIamlIged three I'OOW and a batbtoGm. Metzger llveS below road grade and recievtS water from 148th avo S8 and also a ditch to the lIorth other properly thaI is ainted light at her bouse. SIlo bas a &Illall yard dnIin in thClionea.!t corner other IDI that tries to handie this flow.It appears tho small yard dnIiIl couIc1n't handle tho ilcw ofwator and overtopped and llDOded the basc\ll8llt. 1 1 I TIlls roadside ditch has water COJIllibuted by three properties to the llonh otMctzger that draius into this ditch. Mrs. Metzger wants to kDo~ who is responsible for this draiDage and who can fix the probll\l\l. This QJso affecting the down stream neighbor otMctzgcr, Raymond Schroeder. complaiut number 95~009. I called Mr, .Schroeder and explained that this WOIIld be looked at ~ the NDA review 011 I ~er IX>mplaint and we c~ose his file to Metzger. ."\ ~ I ~ ~ "~ P I \l ~ ~ <Ih;' 4161 f)1 c.,Srpt'/ 'l Wit II a. '(f) SA ~ J '--------="-='~,E~~~~a~_J,.m::;;;;;;!iJ .E'x t~f. ~$. I I Investigated by Date ....... · .. ·WS' ~-----. --_ .... 1 1 1 1 1 1 1 1 1 1 ~ 1 ~ 1 t 1 1 1 NOV. 8.2004 10:35AM KC WLRD NO. 339 P.ll/20 .~ KING COUNlY SURFACE WATER MANAGEMENT DIVISION DRAINAGE INVeSTIGATION REPORT Type c.. fU8'NO'95-~ (DaYi' .. --.. . ... -(e;;~l""" .: Page 1; INVESTIGATION'REQUEST Received by; f ~ Date: I/S 'IS OK'd by: RecBived from: (Please p~nt plainly ~ scanning). NAME: S ch roe;der. PHONE 2. 77-~ I :J:' -""""-"-'I:' ~ CIty Ife,NLO"/ State,--_ Zip5'R ..... ~ ADDRESS: 11170/ :5£ Location of problem, If different: 1'l8Ported Prob/sm: Plat name: Other agencies InvoNeIl: /oI~ ~ ~.!i-Parcel No. /02.305 9357 1/4 S T R Basin ,.., Il Y Council Clst 12. Charge No: , DISPOSmON: TUrned tD~ __ on ____ by __ _ Lot No: Block No: No F)eld Investigation Needed ~ ! Kroll 80S IE ,,,-lOCO ___ ~ .l,.\,..~ ~:lL ~ . ~ OR: ~ further action recomtn~ ( _'G.Jl. =ttl '77j~o ~ Lead agency has been notffied: -Problem has been oorrected. -~N~o:-p=:ro:::lbli:r.e:::m:;h::a:;s b""e'::en:-Tia:l':e:::ntlfI:iDed=-, -----=p:;""ri.,..o:-:r:-;I;::nv::e::s::;:tlgatl:::i"o::n:-:a::::du:dress;:-,-IIS-~, . -Sae File # • . VlJler _ Private problem -NDAP will not oonslcler because: . Water or1glnates onsite and/or on neighboring parcel = location Is outside SWM ::::U. ';7' Ar .. _ Other (Specify): . DATI! CL.OSED:.Q..J.; t.-5/!'S bY:-fi{) .. . -_ .. --_.-'-._ ... _ .... _ .. ---.... -.-_ ... -.... __ ... _. ··-·.:.-5~-9-t/~ /-d·d.tI---------'--._-- ,------------------------ I' I NOV. 8.2004 10:35AMCltlKC WLRIlIJ.,.LVt,JJ.,.L;:'W\:I.."\U .a."''' ~:;:-..: ..... --;,-;:; NO.339 .... I"'\.f"'\ ... __ ....• _. ... • r'4 KING COUNTY SURFACE WATER MANAGEMENT DIVISION DRAINAGE INVESTIGATION REPORT Page 2: FIELD INVESTIGATIO"! LMPLAlNT #195-0009 schroeder ~vestIgated 1-6-95 by Doug Dobldns --------------- P.12/20 '. with MIS. ~ ollSite to discuss her draiDage concems tllat flooded dlc basen'lcnt' Of her house. . . .., . ~. '. basement was flooded 8Dd damaged three rooms and a batIIroom. Metzger lives below road grade and recieves water from 148th ave SE and also a ditch to the north·other property that is aimed right at her house. She has a small yard drain In the norteast comer other lot IlUit tries to handle this flow~ qppears the small yard drain couldn't handle the flow ofwater and, overtopped an4 t100ded dlc bq ...... ent· ~ lOIIdsIde ditch has water QOIItributed by three properties to the nm1h of~ that drains Into this ditch. Mrs. Mcizger wants to know who is responsible 1bl' this ~ and who can fix dlc problem. 'f:blS also affecting the down stream noIghbor ofMelzger, Raymand ~. complaint number 95-0009. I caUedMr~Sch!oeder and explained that this would be looked at under tho NDA micw on r~ complaint and we close bis IDe to Metzger. I I 'a-... - IL." .. "AVE I.-' __ .I~~~: __ .: __ ::_:: .. _:: __ =. ::"::._=_= ___ =_= __ =_ = __ =_=_=_ .. = ___ ==_L,Dat::· :9~.=-:_::. :: .. :::-=-===--::.-=-=---: ---_:-:-..:--~-~,--;Fsi* I NO.339 P.13/20 --KING COUNiY SURFACE WATER MANAGeMENT DIVISION ·.DRAINAGE INVESTIGATION REPORT. Page': INVESTIGATION ·REQUEST. Type c... I .~elv~~ b~: J..!:.:.;_' _._~ ..... ~_ . ....:..~atB:' .. ,2 ~'E. ~ 96' ' ;OK'd b~:' . ~_, Fil:.~~;_i~::.~.l~ (E".) Received from: (PI ... a print plainly t.r oc.anning). . (Day) I .. :·~AME: 12ave .:Jbha$oO· 'RHONE 25~ 2-"86'_' __ _ , :~'AOOR::SS: .. 11625 . .It/8th ·IN&-:5£ clty.-,fen~,.z . StalG . ZlpS#OS l:;:~;;~~:'; pr~~I~;;;. r.·~i~~;e~;:"--~);:9.~='~I~;;fjjj} ~qc. '){;r? '~fz~· ·.;?3:S!t78~ I .. I I' I· I I . . . . '. 0.+ /1615" 1P'~w.; ,l/t)E SE 1>; ~n*f '~n? ~p;" 'da~/l~n l«i~Au, /6 . P/iJodt'n,f' -/--he' . ~A/7sc?J'7:S-and . .mehXu-5 . j?rt?p-!y, 7h~ (!u/ver! ¢In· 1L/-8~" Ave SF. J.£fJJ5 -rv BE ~n/arJ~>' . .. . . : Lo~ No; " : " No Field Inv8s:igs.;ion I'/itedad __ .,.. Ne: to 23 6 . ?arc91 ~o .. lOt 3 0 Kro~ ~oef.. . ih.3ros: N~" .. (p'Zr;"J' ;/~ . ST' 1\ O:d UJ Z. 7 A,: I '. ' Basi" rnA 1" Council DiS! 12.:. eMerge No: ~'8D4 I eo'f . R;SPONS~." Cltl4e,n notified o~ t,-Z9-" by .lL phone _ letter ~ In perso~' --. I;' l.~~~e~,-~ ~, P:C ~::&~ M~~~~~. ~ ".' . I -Gte t-b~ -b ·'I:?--J.S. ~~. ~~~'"l"'" DISPOSITION,: Turned \0 on OR: No further aclion recommer,ded gel I jQ ~ead agency has bee,., n'o;lf1Bd:' _ -'-~~~;::=!.f.~~. ~'~A4~cJ'L.lz.....~·_-=:-:-;:~±=~=:,:~ ::=:",:,::: .. -:\~. _ P~oblem has be~n correcled, _ No problem has been Idenl lied. frior invastlcal10;J addresses pro -s... RI. ,,~. . _ Priv~re problem. "'DAf> 1'1/11 nor consider bec2'!se; . . . . I '. -Water ortginates onshe and/or on neighboring parcel ,: .. _ Locallon I~ outside SWM s~ea. . . _ Othllr (Speci1')'): 1----DA:TE,CLOSEO:---~-'lrJ!fJI9 t. _,_b~~, ---~-f=f).,..-o1f'f)S--"-.------"------,, ___ : --------~ ,KC WLRD . 'NO.339 , : P.14/20· .' . NOV. 8.2004 ,.10:,~I?AM .. w I I I I I I I I I· I I \ I " I I I I 'I':·'::-"'::'c-..... f rind. "'.' '_ ) COMPLAINT 96.()185 JOHNSON. DAVe Investigated by Doug Dobkins on 2-21..gs , ' ,. r n 71';"1. Mr. John/,!qn was not present at the time of Investigation. I left a door hanger with card and phone.. Mr. Johnson Is, concerned about the runoff from 148th ,avenue SE flooding his property and the neighbor to the north of hi~ property Metzgers. There Is'a catchbasin at the northeast comer of SE 118th and 148th Ave SE which backed up during the storm on February 8th. The pipe under 148th could not handle the capacity and backed up onto 148th and ran to the west onto Johnson's property and on Metzger's property. This problem looks to be created by the Intense storm on February 8th. I will call Mr. Johnson to find out whether the water bacl.<ed up from the catchbasin or bypassed the basin and ran'down the driveway. NDA project'on the neighboring property of Metzger. Both live below road grade. LEFT MESSAGE WITH DAVE JOHNSON ON 2-26-96 SE 116TH ST OPEN DrrCH ' 148TH AVE SE ---_._--------- .-... ----~.-.---------~ "~-.-. ----'--'-.--------.~.-.------.. -.----.---.------------, ... _~. __ r ---------------------------- I · NOV. 8.2004 10:36AM KC WLRD ___ NO. 339 P.1S/20- K1NIS COUNJY'SURFACE WATER MANAGEMENT DIVISION .'.. , DRAINAGE INVESTIGATION REPORT ... -., . I Page 1: INVESTlGATION·ReQU.esT A ~oj Type G Recelvedby:.T.L'. Date: ~.~Z.3,q6 OK'dby: -ffjQ··FlleNo, qft;-55'2.... IlsceiVsd from: (please prtrrt plainly for scanning). (Day) , (EYe) ftME·~_--!:;~..::::a.!r,I!:Y.!.!.IYl:..!!:::.on~d!.....4-' ---L.-r,~'0'Y'7,-,-_______ PHONE 2$, .. 978~ ___ _ .,DRESS: ...... ju/~6;u/_5'--_1'-4:;z.· ""8'-71-,_....J.A,..!...II.~'€~--'s.::I:;{=--__ city Ren-tDf'l . State __ Zip '1'S05cr Eon of proble.m. If different: eported Problem: . I. I' I 1 I if'lname: 'tiler agencies Involved: r:'lacde-d r()adwa..y, cIai'm, . .. '". ,. ". ~ ... .. ~~.:O' •• . . ~ .... " tjuJ-er mn-r . .;be h'/ /'I?tJ "'<.. Lot No: Block No: No Field Investigation Needed ..,...-__ Parcel No. /0.2. '3 O!5 1'3'53 Kroll 205 e ThBros: Newlp2t, ;:r(J) . Old (P'2..7 Af..p Council Dist lp. Charge No: ~5.D3) ~~ rNSE: CitIzen notified. on 4i2.ft(r by fohon~ _ letter _In person I rPOSITION: . Turned to-lt., ~n 31tt1~ by ~ _ Lead agency has been notified: . .' ~ Problem. has been corrected. -_---..,N~o:.--:::pro=bI-:::em=hilS::::;:b:::e-::en:;ldF:ie-:::nt:;:;lfl;;:ed::;.-----;p::;:rlr=o=-r I;::nv::::e::::st:r::ig=:atl:r.:o=n-::a-::;:da:r:ress=e::s:-:p~roblem: -See Ale # • ~ P{/'vare problem-NOAP Wfll not consIder because: . .~ .. '. _ Water originates onslte and/or on neIghboring parcel ~"CLOS~1?;;_~&;-~~iiF~~,I~=,~. .. OR; No further action recommended because: NOV. 8.2004 P.16/20· I .. . .",,-'.~'l/I-. _ ." 10:36AMN KC WLRD' --• -~-"''-UU'''''' .... v '.L'U. V o.\,NO.339 . ,,,:,.':'1 a .u"<j'::lVv3~VN'v'W I:13.LVM :lo'V":Jl::lns A.J.Nnoo £>NI)f .......... i , 1 _, •• _._ I I I I I I I 1 I I I I I Date: March 7. 1996 lJ..e of Jime8tlgatioDI March' 6, 1996 BE: EvAluatioD for Compladnt': 96-0552 Tim Raymond tLynnMeIzker 1161S 14&11 Avenue SB lWdim, WA. 98059 Day P 235·918$ Ms. Mcaket's home lies belOw the mad omatioII of 14&11 SI'!. She &IB1ed that during the heayY !lIin1IIUs otFe1mwy. 1996, she expericoI:cd water Inside the house. Two basement living rooms were damaged. The carpets had to be replaced QDd the walls re'painted.. Ms. Metzker mdcl the Water Is llowiDg ttom SB'116th Street., aver the properly to the north and also down a c:ulvcrt In the &om otthe ~ 10 the north. The QUlvert water flows inro a CB in the JIIItIheut cmncr ofhcr property and then 0UItiIlls next the the ~ wIndoWil. This has happcPed 8l1east once a year in the tow yeus she has owned the propcr1;Y. Sbc WIIIl!lOt _ ofthe.water problems when she bougbt the home. .' She 1ceIs that water Is COIIIlDg down tbe sam (1481h) ftom some zecellt development. I rec:oJI1DIeIl4 that this be tnmecl over the the NDA Progmm for fbtI= stuc\y. \~V~~ '\ .. T ~ .... \(~N.J>./ :'\ /. ~~1k."f... \. I , 1 1'. I .: I ~ t:;:.;" I ~I~J =====~:.--~ . I ,~ ---.. -----ct) .... '=---"'..y--L~--I.' f' , " , .. . . _.'4.,. .. . .. __ --.:.\~.:;:;..~ D.M.;..~;.-E:';....-_______ ....... -••. ----.-,--.....,....-----i I ~ t~ I I'~---. __ ~ ...... __ "" __ ._" ............. _ ...... ___ ' ......... _. __ ....... ___ .. _..c_. __ ~_ ... __ . ~--..... -1-.. I I I I I I I I I I I I I I I· I I '4{". , Date: Mari:h 26, 1'96 I'M: .Jeff" .Jac:obSOD NeigJlborhood DraiDage Aslillallce PrograJll COlllpl8lnt EvaliJation Memo RE: NDAP Evaluation for CoIIIplAint # 9<H15S2 Tim Raymond fLynn Metzker U61S 148th A_ SB . RenImJ, WA 98059 Day P 235-9785 CompIa!!!t Chroru/Jm! B!!£km'lUld Original: Field Invest: FieldEval: 014Fi1es: 2-23·96 3"()7-96 3-25-%; 4-02-96 94-1000, !lS"()()()9 P.17/2~ Tim Rayuiond, the complainant, called Februmy 23, 1996. The house sits 5 to 10 filet below the SIII180e of 148th Avenue 88. He'says runofffrom the roadway 120 feet to the north(SB 116th Street) is flooding his bllSCDlC\lt. TIrls road is not lIIalnWnec! by the county. This has been a tHOCU11'i1Ig pmbIem for him ever siIICC be bought the house. Mr. lIayDlOlld Is the first 0WDet ottbe bouse, He claims this sort of f100dlDg oceIUlI four or 1ive times a year. Lynn MctzI=. the cunent occupant otthe bouse, had called In a complalnt ))ecember of·1994. The lnvestigation was tunle4lnto a NDA review. The NDA review was given a top priority SCXIlC. Howevet. be£oJe any CODStructlon took place the owner of the bouse had installed a catch ba.sIo/conveyance II)'IItem ofbiB own. The system iDsIalled by the owner was VIllY similar to the system'recQmmeJlded by the c:ounty. Thmefore, the COUIIty e1ecte4 to cance1 the construcIion otthe proposed NDMimded IXIll\'CyllIlCe system. Findings During my site ilIvestigation on April 3, 1996 I held a COIlVel!IIltion with Mr. Gerspach. Mr. Gerspach is . the property owner abutting Ms. MetzkerlMr. Raymond to the north. He claims lie oxpetienQcd some minor fJcvJding on Fe1mwy 22, 1996. ~. some vandals had destroyed a 1ire hJdmnt on the intersection of 148th Avenlle SB and sIn 16th Street. The 1ire hydrant Is located 112 blOck uphlll from the MeI2:ker IIonle. Mr. Gerspach noted the Metzker household eicperieoced damage of the living space in the basement due to this act Ofvan4alISlll I aalled Ms. Penny Merrill with King Coun1;y Water/Sewer DJl/lIlct No. 90 on April 3, 1996. She CODfinned an act otvandalism had occurred iuvolvillg 1ire byd:ants on PcbJwpy 22. 1996. Additionally, she bad a toOOfded colllPlointfrom 11615 148thAvcnue SE on this night -the night otthe vaadaljsm. . ..._---_ .. -_._._--------_ .. _-----. .._-----._------------.--------------I ' "-,-,---------. ~ .. ---.,-----.----.------- I I I I I I I I I I I I' I I I I I • 37AM KC WLRD NO. 339 P.18/20 ThjsBJ\llrCs9 isMs. MeIzkm'. Ms. Metzker placed a call to SWMon the tlI1Iowfug date: Febrwuy 23, 1996. 'l1Ils dralIIage, ptoblen! does DOt qualify under the NDA Program criteria. The problem WlIS DOt part of a 118tWal stol'mevcnt, The problem WIlli Qluscd by an isolated act ofvnndalism RDd not a storm event. This WlIS the filEt f100dlug compJatpt received since the oompbdnt Ioggeclln December ot 1994. Mr, Raynlond did npgrqde his storm l:O.nwy&llCCl system since the original complaint My conversation with Mr. Raymon4 wilMon a site invcstfgatiOD, March 25, 1996 revtJild the catch basin system located on the northeastern pottiOD of the property was adequate for the water received. At that limo, Mr. Raymond'~ prIma:ry CODlietll was the meet:flow comIDg off the ~'s pro~. Thls sheet flow 'MIS obviously an iBloated event caused by the damaged fize hydrant Having tee:elved no additional COJ!lpJalnts for the Iast two major m011ll aveuu, November, 1995 and Febrwuy 8, 1996, respectively, SWM considers the file closed. -. --. . .. -------------~-------........ '1'-.. _._ .. -_:: .... -.--_ ...... -.--... ----...... --"-,---""'-""-,.-,~,, ---.-.-,.--~--,.-.--"'-_.---- 10:37AM----KC WLRD NO. 339 . KING COUNTY WATER~ RESOURCES DmsxoN DRAINAGE INvESTIGATION REpORT P.19/2:j5 _ .• ..t::: I" P~l: ~noNREQmmT . PRoBLEM:, [y1Wyt.q& ru;caMmBY" fV\A/V Date:12fZ2 OK'dby:~No.gq-OI?1 Type ~, I I I I I Received from: Plat name: Other (Day) (4'2) PRoNB 25+ -2828 (Eve) L( _...I) City f.eN.mN S~te~_ Zip qgWZ Lot No: Block No: No field investigation J"eq1lirecl.."...,,.,..,..,. _ _r_-' ---.r. . _'.::-~-_,""._ ------~~ ---- - -.. , ~~ -..I.!!......f:::'=~ 6 it Parcel No. !Oz..'OD'5 -4,b42.. KroUS'Zl5 e ThBl'Os; New !.p2Jp:r rJ • Old ~SD4-, I' B~ .' ~ Coun~District{P , , Cb&rgeNo., ____ --- REsPoNsE: Citizen' icifJ.lied o~ ~hl!lf by: ...k::':. phone letter ._ in pemon , I t>..l... -efi"";;-~t>~.s:~1J' rl.t/f'r sf>~ ·(p~Ut-O ' /I1~.v A-t:;;eri>If',./q(". . I 't?1t1'1 (r ro <A.J~~/\ .(~ t.s7.Jf'~U.AJ" ,f)/r~.I"'/A.."~ a.,'V~ .• ' ..+1AJ D 6-+v-f> H f',-t , ;:;-if..t-,v ih?.87k'r.. ' . DISl'OsrrION: Turned to _ on I / by_ OR.: No further action recommended because: I -Le!id agency has helm Tloti1i!ld:_ \ ' . ~ Problem has been corrected. __ ' No problept has been idCDtlfled. _ Prior investlsation addresses problem: , SBEJD.aN ' I -Privateproblein -N,DAP will not consider because: __ Water prlginates onsite and/or on neighboring parcel .-Location is outside WLRD S~ _Other (Specify): I DATE CLOSED: '3/ / I / 1'-By: --,"'L:L~~ , /I'-'p:;p,a,t/(().rb. __________ . ____ _ -- ---.---.-------~-------,--------'.--'--~ -------------I~:=':-----_.-.. ' --.. -... -.--- I I 1 I I, I 1 I I • ' I I I I I I ~ --. -----_. - ----------------------- Complaint 99-01 S 1 Rutledge Investlgared by Pat Slmmons 03101199 I met with MS. Rutledge about the drainage that flows in the Horse pasture behlnd her home. The water flows out of a pondlwetland and through a swale that is about so feet from her South fence. The water is about 2 fcct wide OD the West edge ofherpropcrty and S-6 feet wide on the East side ofthe.parcel. This sppeam to be a Datum! dralnage COIll'!le thaI flows when the wetlandlpODd get twl enough. She would like to la!ep the Stream DarroW 10 allow l!1Ofe room for the hon;es. I stated that I would look Into!!te nature of this drainage 10 scc how it is protected under CUlTent codes and provl4e her with some informa!ion on the restrictions near the dralnage. 142nd Ave SE PondIWetiand 11642 Rutledge Pesture NTS • ::;:,::.:t· .. ·::' ::.' .. : ..... . :'$.±>1:(;5· / j 22/ ,.," . "H ... • .--" .............. 'v., ,,'" -........ ~.-. ,....-----UOJO I au f 00 KC RA-5 THOROUGHBRED RANCH UC 1800 SE 7TH CT RENTON, WA 98055 -', j I I ....... _1 . INTERNATI~.N.1.A~L~Xi!fj~~ _!!!!!!!I THE FOUR '" . 11840 RENTON. WA 91)5~tt 06381uu.<_ MICHAEL A & BARBARA J PAXHIA 11920. 148TH AVE SE RENTON. WA 98059 0638100210 -'-L'A "T 1/4 CORNER ·FOUND CONCRETE MONUMENT IN CASE . W/LEAD DISC AND TACK OWN. 1.5' KC' RA 5 I I I (11-16~OO) '. - 1I'IlIIIi!I!" l =::''':IIII!I!J!I!I-1Ii!!!L IIi!!!L 1Ii!!1!!i!... ~_Ii!!1l!!!!! __ ,. r King County DEPARTMENT OF DEVELOPMENT AND ENVIRONMENTAL SERVICES LAND USE SERVICES DIVISION KING COUNTY, WASHINGTON PRELIMINARY REPORT TO THE HEARING EXAMINER March 22, 2007 -PUBLIC HEARING AT 9:30 A.M. DOES Hearing Room 900 Oakesdale Avenue Southwest Renton, WA 98057-5212 Phone: (206) 296-6600 PROPOSED PLAT OF EAST RENTON FILE NO: L02P0005 PROPOSED ORDINANCE NO: 2007-0010 A. SUMMARY OF PROPOSED ACTION: . , This is a request for a subdivision of 17.01 acres into 66 lots for detached single- i family dwellings. The proposed density is 3.9 dwelling units per acre based on gross area. Density based on net buildable area of 11.88 acres is 5.6 units per acre. The lot sizes are predominately 5,000 square feet. See Attachment 1 for a copy of the proposed plat map .. B. GENERAL INFORMATION: Developer: Engineer: STR: Location: Zoning: Acreage: Number of Lots: Density: Lot Size: Proposed Use: Sewage Disposal: Water Supply: Fire District: School District: Camwest Real Estate Development, Inc. 9720 NE 120th Place, Suite 100 Kirkland, WA 98034 Contact: Sars Slatten 425-825-1955 Triad Associates 12112 115th Ave NE Kirkland, WA 98034 Contact: Gerry Buck 425-821-8448 10-23-05 West of 148th Ave SE at approximately SE120 th St. Parcel -1023059023 R-4 17.01 acres 66 Approximately 3.9 units per acre Approximately 5,000 square feet in size Single Family Detached Dwellings City of Renton Water District # 90 City of Renton Issaquah School District Complete Application Date: April 17, 2002 C; HISTORY/BACKGROUND: The Subdivision Technical Committee (STC) of King County has conducted an on- site examination of the subject property. The STC has discussed the proposed development with the applicant to clarify technical details of the application, and to determine the compatibility of this project with applicable King County plans, codes, and other official documents regulating this development. As a result of preliminary discussions, the applicant presented the Technical Committee with numerous revisions with the most recent plat revision on March 17,2006. The modifications from the initial submittal include: • Revised entrance to the plat • Revised location of recreational space • Clarification of the sidewalk improvements to be constructed along frontage and within the plat. • Adjustment to the buffer and BSBL lines associated with the on site wetlands. • Revised plat boundaries, eliminating the far west portion (2+ acres) from the plat application. Boundary revision was completed under file L04L0055 and recorded under # 20041223900001. The purpose of the boundary adjustment was to separate that portion of the site annexed into the City of Renton under Ordinance 5147, effective on July 6,2005. • SWM Adjustment L02V0089 approved allowing the diversion of runoff to a single facility. • Subsequently SWM Adjustment L04V0103 was approved 3/24/05 for shared facility concept of the northeast corner of East Renton to utilize eastern drainage facility in Rosemonte. • Road Variance L03V0049 approved 10/20/2004 for a 620 -foot vertical curve with 455 feet of stopping sight distance, utilizing a two-foot target. Additionally approved is the slight grade break (under 1 %) at the north end of the vertical curve. D. THRESHOLD DETERMINATION OF ENVIRONMENTAL SIGNIFICANCE: Pursuant to the State Environmental Policy Act (SEPA), RCW 43.21C, the responsible official of LUSD issued a mitigated threshold determination of non- significance (MDNS) for the proposed development on December 15, 2006. This determination was based on the review of the environmental checklist and other pertinent documents, resulting in the conclusion that the proposal would not cause probable significant adverse impacts on the environment provided mitigations measures are implemented. Subsequently, staff recognized incorrect references to other subdivisions and issued a REVISED MDNS on December 29, 2006 referencing the following mitigations: 1. To mitigate the Significant adverse impact the plat of East Renton will have on the intersections of SR 900/148 th Ave SE and SR 900/164th Ave SE, the applicant shall install, either individually or in conjunction with other development projects in this area, the following improvements at the SR 900/148th Ave intersection: • A traffic signal, and • Eastbound and westbound left turn lanes FILE NO L02P0005 Page 2 The design for the SR 900/148 th Ave intersection improvemen~s shall be approved by the Washington State Department of Transportatton (and by King County to the extent such improvements are located in County right-of- way). In addition, at a minimum, the existing entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet, respectively) shall not be redu,ced as part of t~e inte~section .improvements. Documentation shall be submitted to show thiS requirement IS met. All construction work associated with the intersection improvements shall be completed between April 1st and September 30 th . This seasonal restriction shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarante.e ~ith WSDOT which assures the installation of these Improvements wlt~ln two years of the recording of East Renton. In this event, i~tersec~ion improvement design must be approved by WSDOT prtor to King County approval·of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the. recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these . improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-rata share dollar amount to be paid shall be set by WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip distribution for East Renton • The total trips contributed to the intersection of SR 900.148th Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P3008), East Renton (L02P0005), Shamrock (L02P0014), Rosemonte (aka lronwood- L03P0018), Martin (L05P0019) and any future land use applications submitted to King County for which compliance with the King County Intersection Standards (KCC 14.80) is required at either the SR 900/148 th Ave intersection, orthe SR 900/164th Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu of the approach described above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years of the date of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21A.28.060A] 2. Documentation shall be provided to demonstrate to the satisfaction of WSDOT that stoPRing sight distance (360 feet) is available on the east leg of the SR 900/148th Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 148 th Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 21A.28.060A] 'An environmental impact statement (EIS) was not required as a result of issuing the MDNS. The appeal period for the revised threshold determination ends at the close of business on January 22,2007. The specific mitigation measures have been incorporated as part of the applicant's proposal and are included in the list of recommended conditions of preliminary approval. Agencies, affected Native American tribes and the public are offered the opportunity to comment on or 'appeal the determination until January 22,2007. . FILE NO L02P0005 Page 3 E. AGENCIES CONTACTED: 1. King County Department of Natural Resources and Parks: Comments are incorporated in the discussion in this report regarding wildlife. 2, King County Fire Protection Engineer: Fire protection engineering preliminary approval has been granted subject to the standard code requirements and requirement for sprinkle ring of homes unless higher standards for road improvements are met. 3. Issaquah School District: The comments from this district have been .incorporated into this report. 4, King County Water District #90: The comments from this district have been incorporated into this report, 5. City of Renton (sewer provider): See Attachment 2. 6. METRO: No response. 7. Washington State Department of Ecology: No response. 8, Washington State Department of Fish and Wildlife: No response, 9. Washington State Department of Natural Resources: No Response 10. Washington State Department of Transportation: The comments from WSDOT have been incorporated into the SEPA TD and in this report. F. NATURAL ENVIRONMENT: 1, Topography: The site slopes from east down to the west with an overall elevation change of approximately 60 feet aGross the site with 20-30 percent slopes on the central 1/3 rd of the site. 2. Soils: Two types of surfaces soils are found on this site per King County Soil Survey, 1973. a. The east 2/3rds of the site is classified as AgD -Alderwood gravely, sandy loam; 15-30% slopes. Runoff is medium and the erosion hazard is severe. This soil has a severe limitation for foundations due to slope, and a moderate slippage potential. It has severe limitations for septic tank filter fields due to very slow permeability in the substratum. b, The west 1/3rd of the site is classified as AgB -Alderwood gravely, sandy loam; 0-6% slopes. Runoff is slow and the erosion hazard is slight. This soil type has a moderate limitation for low building foundations due to a seasonally high water table, and severe limitations for septic tank filter fields due to very slow permeability in the substratum. Soil exploration was preformed by Associated Earth Sciences, Inc. in April of 2001 and Technical Memorandum, dated September 24, 2002 indicates slopes 15 % or over are moderately susceptible to erosion, however they concluded is that with the design of the outfall the storm water flows will not be susceptible' to erosion. 3, Wetland/streams: A wetland/and or stream report was prepared by C. Gary Schultz dated April 3, 2001 and revised September 12, 2002. The wetlands (A, B & C) are classified together as Class 2 Wetlands, These wetlands are part of a wetland system exceeding one acre in size and include forested area as the headwaters of Honey Creek. Some buffer averaging is proposed along the east side of the on-site wetland. FILE NO L02P0005 Page 4 " r While this subdivision as presented has been determined to comply with sensitive area provisions, the adjoining plat of Rosemonte currently as designed will either need to shift the street east so that the retaining wall is outside of the BSBL (this would change the street alignment of 145 th Ave SE) or instead propose additional buffer averaging in Rosemonte to allow the BSBL to be shifted west. According to the Conservation District maps, the site is characterized by a high water table. The site lies within the Honey Creek subbasin of the May Creek drainage basin. 4. Vegetation: The west third of the site is heavily wooded with a second and third-growth mixture of coniferous and broad-leafed trees native to the Pacific Northwest. Within the wetland itself, there is predominately Red Alder. The remaining portion of the site (east 2/3rds) is primarily covered in pasture grasses. Scattered evergreen/deciduous trees and brush occur in limited numbers. 5. Wildlife: Two Red Tall Hawk Nests were identified back in 2001 with the central one determined to be abandoned and the northerly one active. The applicant has proposed on the most recent plat plan location of lots at a minimum of 250 feet from the nest. Such birds are not listed as threatened or endangered species nor are they protected in the Urban area of King County. Other small birds and animals undoubtedly inhabit this site; and larger species may visit this site on occasion, however, the population of species is limited due to increased nearby development. · 6. Mapped Sensitive Areas: The Sensitive Areas Map Folio indicates that there is a wetland which crosses over from this property onto the property to the north and · south. G. . NEIGHBORHOOD CHARACTERISTICS: The property lies in southeast King County, north of the City of Renton on the west · side of 148 th Ave SE which provides arterial access to the site. The site is designated as Urban and is within the urban growth boundary. In recent years there have been numerous plats in the local area approved by King County. This East Renton area is in transition from a rural residential area to a low to medium density urban setting. On this site there is an existing residence and detached garage and the remaining upland portion is manly in pasture. The forested area on the west third is the lowest portion of the site and contains the wetland noted in this report. This property and other surrounding property in the Urban area are zoned R-4 (Residential-4 du's per acre). Properties east of 148th Ave SE and north of SE 120th st. are zoned RA-5 (Rural Area - 1 du per 5 acres). Additionally, these properties are outside the Urban Growth Boundary. 148th Ave SE is a 60 foot public right-of way and the right-of-way is within the Urban Growth Boundary. H. SUBDIVISION DESIGN FEATURES: 1. Lot Pattern and Density: The proposed lot and street layout is in conformance with King County Codes (i.e. KCC 21 A and the 1993 King County Road Standards. ,Density calculation for the plat average is 3.9 d.u.'s per acre based on total acreage of 17.01 acres. Code would allow 68 lots under the base density provisions. Minimum density code provisions require development of at least 35 lots. Density of the net buildable area of 11.88 acres would be 5.6 dwelling units per acre. The 66 lots are · generally 5,000 square feet in area and have a width typically of 50 feet. See Attachment 6 for the Density & Dimension Calculation Worksheet for further details. Additionally, Tract E a future growth development tract is proposed between wetlands on the far west potion of the property. This tract is 48,128 square feet in size and is FILE NO L02P0005 Page 5 almost totally surrounded by sensitive area/wetlands except on the south tract boundary which also is the south property line of the plat. Future development of this tract would be subject to Critical Area Code requirements which could require additional property be set aside as buffers. 2. Internal Circulation: Lots will front onto the internal public streets that provide access within the subdivision and exits out to 148th Ave SE. Additionally street stubs connections are planned which would provide access to properties both north (145th and 14ih Ave SE) and south (145th Ave SE). See the proposed plat layout, Attachment 1 to this report. The applicant has stated that the future development tract could be served with access from the southerly abutting property, however though preapplication review of the abutting parcel, it appears access to the proposed future development tract on East Renton could not be provided due to the extent of wetlands to the south on the abutting parcel when applying code limitations of KCC 21A.24. 3. Roadway Section: As proposed by the applicant, 148th Ave SE frontage will be improved with urban improvements, including curb, gutter, and sidewalks. A road variance was approved allowing an alternative design for improvement (see Attachment 3. The internal public street planned as SE 11 gth St. will be improved as a subcollector street, as will the proposed 14Sth Ave SE from SE 119th to the south property line. SE 120th St and 147th Ave SE south of SE 119th St will function as a subaccess street and 146th AveSE will be a minor access. 4. Drainage: The proposed subdivision includes an underground storm water vault located within Tract G shown on the preliminary plat. Since the drainage facility will be located below ground, the surface area will be utilized as a recreation space for the future homeowners. A portion of the subdivision drains northerly to the property currently proposed for development as the Rosemonte subdivision. Since the King County drainage manual requires storm water to be discharged at the natural location, the applicant requested a drainage adjustment to divert storm water from the northern portion of the site to the proposed storm vault. This adjustment was approved by King County in 2002; however, the applicant revised the proposed drainage plan in 2003 after the adjacent parcel of land was proposed for development as the Rosemont subdivision. The current drainage plan shows an offsite detention pond located within Rosemonte which is designed to accommodate drainage for Rosemonte and the northern portion of East Renton. To allow an offsite drainage facility, the applicant requested approval for a second drainage adjustment to allow a shared facility for both subdivisions. As shown on the preliminary plat map for Rosemonte, a detention pond is proposed within Tract C (per 3/8/06 revised plan) which will provide designs for flow control and water quality treatment. The drainage adjustments for the original diversion and the subsequent adjustment for a shared facility are both shown in the staff report as Attachments 4 and 5. In accordance with the 1998 King County drainage manual, the drainage facilities will be designed for Level 1 flow control and basic water quality treatment. The site is located within the Honey Creek subbasin which drains to the larger May Creek watershed. The King County basin plan for May Creek has evaluated the Honey Creek basin and recommends that future development in this area use the level one flow control standard as shown in the drainage manual. A review of the downstream corridor in the immediate vicinity of the project did not identify any specific drainage problems. After construction and acceptance of the storm water vault and detention pond for the subdivisions, the drainage facilities will be maintained in the future by King County. FILE NO L02P0005 Page 6 i '. I. TRANSPORTATION PLANS: 1. Transportation Plans: The King County Transportation Plan indicates that 148th Avenue Southeast (adjoining east boundary) is designated as a collector arterial. The King County Non-motorized Transportation Plan indicates 148th Avenue Southeast as part of the plan and is to accommodate bicycles as a shared roadway. 2. Subdivision Access: The East Renton subdivision will provide urban road improvements with curb, gutter, and sidewalk for both the internal roads and frontage improvements along 148 th Ave SE. During preliminary review of the , roadways, King County determined that the existing crest vertical curve along 148th Ave SE did not meet design standards for stopping sight distance. Due to the substandard road design and the need for improving the property frontage, the applicant submitted a road variance application to evaluate design requirements for the roadway. As shown in Attachment 3, the road variance was approved by , the King County Department of Transportation to allow reconstruction of the frontage road to provide 455 feet of stopping sight distance. To provide adequate walking conditions for school children, an offsite sidewalk will also be provided along 148th Ave SE, extending northerly from the site to an existing crosswalk at the intersection of SE11 yth Street. Due to the topography and existing road improvements near the crosswalk, the applicants design for the sidewalk shows a rockery located outside the right-of-way on private property. The applicant has contacted the property owner regarding acquisition of a road easement, however this property owner has not clarified in writing a willingness to' negotiate to allow easement rights, therefore final resolution has not been provided , at this time. During final engineering, the applicant will need to obtain an easement for construction on private property or prepare an alternative walkway design which satisfies the deSign reqUirements within the existing right-of-way. It is possible that the applicant could design improvements on the east side of 148th that would meet the walkway requirements, as well. Access into the plat will be provided off 148 th Ave SE. The planned stub street to the south may someday provide for a secondary access out to 148th Ave SE. and will improve the connectivity between subdivisions. 3. Traffic Generation: It is expected that approximately 660 vehicle trips per day will be generated with full development of the proposed subdivision. This calculation includes service vehicles (i.e., mail delivery, garbage pick-up, school bus) which may currently serve this neighborhood, as well as work trips, shopping, etc. 4. Adequacy of Arterial Roads: This proposal has been reviewed under the criteria in King County Code 14.70, Transportation Concurrency Management; 14.80, Intersection Standards; and King County Code 14,75; Mitigation Payment System. a. King County Code 14.70 -Transportation Concurrency Management: The Transportation Certificate of Concurrency dated April 9, 2002, indicates that transportation improvements or strategies will be in place at the time of development, or that a financial commitment is in place to complete the improvements or strategies within six (6) years, according to RCW 36.70A.070(6). \ b. King County Code 14:80 -Intersection Standards: The existing arterial system requires improvements to accommodate the increased traffic volume generated by this proposal. As a result, DDES issued a MDNS which calls for the mitigation needed to address the impacts resulting from added traffic onto , local intersections rather than reqUiring an EIS prior to action on the preliminary plat application, see Section D of this report. The appeal period for the Threshold Determination closes January 11, 2007. FILE NO L02P0005 Page 7 c. King County Code 14.75 -Mitigation Payment System: King County Code 14.75, Mitigation Payment System (MPS), requires the payment of a traffic impact mitigation fee (MPS fee) and an administration fee for each single-family residential lot or unit created. MPS fees are determined by the zone in which the site is located. This site is in Zone(s) 442 per the MPS/Quartersection list. MPS fees may be paid at the time of final plat recording, or deferred until building permits are issued. The amount of the fee will be determined by the applicable fee ordinance at the time the fee is collected. J. PUBLIC SERVICES: 1. Schools: This proposal has been reviewed under RCW 58.17.110 and King County Code 21A.28 (School Adequacy). a. School Facilities: Students from the proposed plats of East Renton and Rosemont will be served by Apollo Elementary, Maywood Middle, and Liberty High School. As a result of the passage of time (nearly 5 years between the April 2002/East Renton Request for School Information and the date of preparation of this staff report) following the receipt of the response from the District, the STC has reconfirmed the school service boundaries by checking the School District's web site, and the 'service area'/Attendance map pages for each of the applicable schools. b. School Impact Fees: Currently the Issaquah School District required that an impact fee per lot be imposed to fund school system improvements to serve new development within this district. Payment of this fee in a manner consistent with K.C.C. 21A.43 will be a condition of subdivision approval. c. School Access: Apollo Elementary School is located to the north of the subject subdivision, off of SE 117th Street, east of 148th Avenue SE. According to information provided by the Issaquah School District, students of this age group would be provided bus transportation to the school due to conditions along the walkway route unless sidewalk improvements would be provided along 148 th Avenue SE (see Condition 12). The Subdivision Technical Committee (STC) has recommended that, in addition to the urban shoulder improvements across the frontage of the proposed subdivision, that urban improvements be provided across the frontage of the abutting (and, related by ownership, access and required off-site mitigation) proposed plat of Rosemonte (FKA Ironwood), DDES File # L03P0018. The existing designated crossing across 148th Avenue SE is located immediately off-frontage from the northern subdivision boundary of Rosemonte, therefore, the STC believes that additional improvements -off-site to both plats' frontage -is necessary to provide adequate walkways for this age group. Such improvements should meet the urban standards for sidewalks and curbs due to location on the north side of the intersection, the need for a railing, and traffic volumes on 148th Ave SE. Additionally, due to the potential need to construct a curb and gutter section along the east side of 148th Avenue SE (to re-profile 148th Avenue SE, and maintain the resultant slope grading within existing right-of-way), the STC recommends that if the project proponent elects to implement this option, that a graded surface be provided to ensure that school-age pedestrians are provided an acceptable-width walkway surface behind the curbing. Maywood Middle School is located to the south of the proposed subdivision, on the opposite side of Southeast 128 th Street, in the 14400 block of 168th Avenue SE. Students of this age group are provided bus transportation to/from the school due to distance and the traffic conditions along any potential walking routes. The District had requested that a safe waiting area be provided at the intersection of Southeast 120th Street/148 th Avenue SE. The STC recommends in the plat conditions that a level concrete 'pad' be constructed to augment the required sidewalk improvements at/near the FILE NO L02P0005 Page 8 r indicated intersection. See Condition 8.h. This improvement will serve the middle and high school··aged residents of both the subject subdivision and the proposed plat of Rosemonte. Liberty High School is located to the south of the proposed subdivision, on the opposite side of Southeast 128th Street, in the 16600 block of Southeast 136th Street. Students of this age group are provided bus transportation to/from the school due to distance and the traffic conditions along any potential walking routes. The Issaquah School District had requested, in its April 2002 response, that a safe waiting area be provided at the intersection of Southeast 120th Street/148 th Avenue SE. The STC recommends in the plat conditions that a level concrete 'pad' be constructed to augment the required sidewalk improvements at/near the indicated intersection. See Condition 8.h. This improvement will serve the middle and high school- aged residents of both the subject subdivision and the proposed plat of Rosemonte. 2. Parks and Recreation Space: K.C.C. 21A.14 requires subdivisions in the UR and R zone classifications to either provide on-site recreation space or pay a fee to the Parks Division for establishment and maintenance of neighborhood parks. At this time, it does not appear that the applicant's plan will provide suitable recreation space as required by code. Additionally, there are no nearby parks where a "fee in lieu" could be applied. In total 25,740 square feet of recreational area is required (390 square feet per lot). East Renton Tract C at the corner of 14 ih Ave. SE. with SE 11 ih St. includes 9,335 sf and Tract G at the corner 145th Ave. SE. with SE 11 ih St. is shown to contain 16,407 sf. Together these tracts equal 25,742 sf., however all of Tract G currently does not fit the definition of flat, dry and usable area. With placement of a drainage vault on the tract, that recreation area on top the vault and any additional area in the tract contoured for recreational use (all 5% slope or less) would be counted towards the total needed square footage. Staff estimates that the vault has an 8,400 sf surface area and given the existing topography not all the remaining tract area could possibly be counted towards the total flat, dry, useable area due to topography beyond the tract. Attachment 7, shows the limiting factors in the cross section of an earlier configuration of Tract G (labeled Tract C). Options to comply with minimum area would include adding additional area to either the current Tract C or Tract G. Staff would not be in support of creating a third tract for recreation, except if such tract was connected to either Tract C or Tract G by trail (Le. conversion of Tract E to recreation area minimally providing a trail). K.C.C. 21A.14.190 requires subdivisions to provide a tot/children play area within the recreation space on site and two additional recreational facilities as listed in K.C.C. 21 A.14.190 E.2. Staff would support a plan with at least one recreation facility on one tract and two on the other tract. Both recreation tracts are located on tracts easily accessible to plat residents. Tract C is near the plat entry on a corner so to provide good visibility and access. Tract G is at a location that takes advantage of the views into the sensitive area (wetland) west of the tract. Also the tract functions in providing storm detention. The request would not comply with all provisions of KCC 21 .14.180 F. and therefore per code, KCC 21.14.180 C. applies to both recreation tracts. 3. Fire Protection: The Certificate of Water Availability from Water District # 90 indicates that water will be available to the site in sufficient quantity to satisfy King County Fire Flow Standards, Prior to final recording of the plat, the water service facilities must be reviewed and approved per King County Fire Flow Standards. All future residences constructed within this subdivision are required to be sprinklered NFPA 13D unless the requirement is removed by the King County Fire FILE NO L02P0005 Page 9 Marshal or his/her designee. The Fire Code requires all portions of the exterior walls of structures to be within 150 feet (as a person would walk via an approved route around the building) from a minimum 20-foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement driving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. K. UTILITIES 1. Sewage Disposal: The applicant proposes to serve the subject subdivision by public sewer of the City of Renton. The City conditioned the extension of sewer to the requirement that the developer sign a covenant allowing for future annexation of the property into the City. (See Attachment 2). 2. Water Supply: The applicant proposes to serve the subject subdivision from a public water supply and distribution system managed by Water and District # 90. A Certificate of Water Availability, dated April 4, 2004, indicates this district's capability to serve the proposed development. Dedication of easements to the district for extension of water mains will be required. L. COMPREHENSIVE AND COMMUNITY PLAN: 1. Comprehensive Plan: This plat is governed by the 1994 King County Comprehensive plan which designates this area as Urban Residential 4-12 dwelling units per acre. The proposed subdivision is not in conflict with the policies of the Comprehensive Plan. 2. Community Plans: The subject subdivision is located in the Newcastle Planning Area and does not conflict with the goals, guidelines, and policies of the Community Plan. M. STATUTES/CODES: If approved with the recommended conditions in this report, the proposed development will comply with the requirements of the County and State Platting Codes and Statutes, and the lots in the proposed subdivision will comply with the minimum dimensional requirements of the zone district. N. CONCLUSIONS: 1. The subject subdivision will comply with the goals and objectives of the King County Comprehensive Plan and will comply with the requirements of the Subdivision and Zoning Codes and other official land use controls cif King County, based on the conditions for final plat approval. 2. Beyond the typical plat requirements, conditions are proposed which would require the applicant to provide design plans and documentation that address the items below to the satisfaction of DOES: a. Acquisition of easements from private property owners with property adjacent to 148th Ave SE are needed to construct road improvements to 148th Ave SE. as proposed. Acquisitions includes an easement for a retaining wall to support sidewalk improvements to the existing crosswalk on the north side of at SE 11th St., and from property owners on the east side of 148 th Ave SE for side slope easements to support the planned. profile/elevation change to 148th Ave SE. FILE NO L02P0005 Page 10 \ Urban road imprdvements on the ~est side of 148th Ave SE along the property frontagel ( and frontage of Rosemonte) north to the north side of SE 117th St. will satiJy the need for safe walkway access to the school. Should the apPIiJant be unable to obtain easements, urban road improvements co~ld feasibly be provided on the east side of 148th Ave SE as a means to elifninate the need for slope easements on the east side of the road and pro1ide an alternative for a safe walking to the SChOOl.. ," b. As designerd, the plat does not provide for sufficient area to meet code minimum for recreation area. As a means to enlarge either Tract C and/or G, lots proposed could be reduced in size, if needed, and still comply with the minimuml standards for size and width without lose of density. Revision to the plat design will be needed to adjust the size recreation area tract(s) to meet crde minimum for recreational area. . c. Tract E (proposed as a future development tract) can not under all reasonable scen~rios actually be developed for lots in the future. When development of t~e south abutting property occurs, access from the south will unlikely be pr?,posed. Such access would require crossing wetland and/or buffer on C\butting property that is not allowed by the code criteria for critical areas in KeC. 21 A.24. Alternatively, staff would support adding Tract E: 1) into the sen~' itive area tract surrounding, 2) designating the tract as open space, or 3) designing the tract as recreational area, if served by trail extending from th recreational Tract G to Tract E, whereby Tract E would function as an extrnsion of recreation from Tract G. d. Buffer averrging is the preferred alternative to assure the retaining wall in Rosemont~off 145th Ave SE is outside of the wetland buffer and BSBL. Should buffer averaging not provide complete relief from buffer and BSBL limitations, then 145th Ave SE must be shifted east. Alignment of 145th Ave SE with n East Renton and within Rosemonte should be coordinated to as ure a workable alignment of 145th Ave SE for the two plats. O. RECOMMENDATIONS: It is recom~ended that t~.e subject subdivision's East Renton ~reliminary Plat Page 1, revised and received March 17,2006, be granted preliminary approval subject to the following rJ'visions to the plat design and conditions of final approval: 1. Compliance with II platting provisions of Title 19A of the King County Code. 2. All persons havinJ an ownership interest in the subject property shall sign 3. on the face of the final plat a dedication that includes the language set forth in King County co~ncil Motion No. 5952. The plat shall comply with the base density and minimum density requirements of thf R-4 zone classification. All lots shall meet the minimum dimensional reqUirtements of the R-4 zone classification or shall be shown on the face of the pproved preliminary plat, whichever is larger, except that minor revisions to he plat which do not result in substantial changes may be approved at th~ discretion of the Department of Development and Environment servires. . Any/all plat bound,ry discrepancy shall be resolved to the satisfaction of DDE~. pri~~ ~o the fub~i~tal of the final plat documents. As used in this cond.ltlon, dlscreprncy' Is.a b.ou~dary hiatus, an overlapping boundary or a phYSical appurten~nce which indicates an encroachment, lines of possession or a c9nflict of title. I FILE NO L02P0005 Page 11 4. 5. 7. The applicant must obtain final approval from the King County Health Department. All construction and upgrading of public and private roads shall be done in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). The applicant must obtain the approval of the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the King County Code. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location of lots as sh'own on the preliminary approved plat. Preliminary review has identified the following conditions of approval, which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual. DDES approval of the drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review shall be shown on the engineering plans. c. The following note shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DDES and/or the Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for individual lot infiltration systems, the systems shall be constructed at the time of the building permit and shall comply with the plans on file." , d. Storm water facilities shall be designed using the KCRTS level one flow control standard. Water quality facilities shall also be provided using the basic water quality protection menu. The size of the proposed drainage tracts may have to increase to accommodate the required detention volumes and water quality facilities. All runoff control facilities shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for recreation space in accordance with KCC 21A.14.180. e. The applicant has received approval for two drainage adjustment applications regarding designs for the discharge of storm water and a shared facility detention pond. The adjustment decisions are contained within file numbers L02V0089 and L04V0103. During final review of the engineering plans, all applicable conditions of the adjustment approval,S shall be satisfied including requirements for the shared facility located offsite within the plat of Rosemonte. f. As stated in the drainage adjustment decision, the offsite drainage pond shall be designed using the Level 1 flow control standard. Basic water quality standards are also required for design of the facility. If a wet pond facility is provided for water quality, the design shall comply with the 3:1 flow length ratio as outlined on page 6-72 in the drainage manual. For evaluation of the onsite storm vault and the offsite detention pond, a soils FILE NO L02P0005 Page 12 report shall be prepared be a geotechnical engineer to evaluate the soils and groundwater conditions. g. For any proposed bypass of storm water from the flow control facility. the final drainage designs shall comply with applicable design requirements In the drainage manual as outlined on pages 1-36 and 3-52. h. As required by Special Requirement No.2 in the drainage manual. the 1 OO-year floodplain boundaries for the onsite wetlands shall be shown on the final engineering plans and recorded plat. . Access and Roads 8. The proposed subdivision shall comply with the 1993 King County Road Standards (KCRS) including the following requirements: a. During preliminary review the applicant submitted a road variance application (File No. L03V0049). regarding the crest vertical curve and substandard stopping sight distance along the plat frontage. In response to the variance application. the King County Road Engineer provided a decision letter dated October 20.2004 which approved the variance based upon specific design criteria for constructing 148 th Ave SE. As noted in the variance decision. the crest curve on 148th Ave SE must be reconstructed to provide 455 feet of stopping sight distance based upon design criteria with a 2-foot target. The final road improvements and design plans for the project shall demonstrate compliance with all applicable conditions of approval as stated in the variance decision. b. 148 th Avenue SE shall be improved along the frontage as an urban collector arterial including all design criteria from the road variance decision. In accordance with KCRS 2.02. the curb location shall be designed at 22- feet from the road crown to provide full width travel lanes and a bike lane. The preliminary design plans for East Renton shows road grading extending outside the right-of-way on the east side of 148 th Ave SE. During final engineering review. the applicant shall acquire easements for any proposed construction on private property or provide an alternative design which is acceptable to King County for road construction within the existing right-of- way. c. The project entry road to 148th Ave SE shall be improved as an urban neighborhood collector. As shown 011 the preliminary plat. the required right-of-way width is 56 feet. d. The proposed roads within the subdivision shall be improved using urban design standards and in accordance with the street classifications shown on the preliminary plat map. e. Tract D shall be improved as a private joint use driveway serving a maximum of two lots. The serving lots shall have undivided ownership of the tract and be responsible for its maintenance. As speCified in KCRS 3.01 C. improvements shall include an 18 foot paved surface and a minimum tract width of 20 feet. Drainage control shall include a curb or thickened edge on one side. f. Street trees shall be included in the design of all road improvements and shall comply with Section 5.03 of the KCRS. g. Street illumination shall be provided along the plat frontage and at intersections with arterials in accordance with KCRS 5.05. FILE NO L02P0005 Page 13 9. 10. 11. 12. h. The proposed road improvements shall address the requirements for road surfacing outlined in KCRS Chapter 4. As noted in section 4.01 F, full width pavement overlay is required where widening existing asphalt, unless otherwise approved by King County. i. 14Sth Ave SE is classified an arterial street which may require designs for bus zones and turn outs. As specified in KCRS 2.16, the designer shall contact Metro and the local school district to determine specific requirements. j. Modifications to the above road conditions may be considered by King County pursuant to the variance procedures in KCRS 1.0S. All utilities within proposed rights-of-way must be included within a franchise approved by the King County Council prior to final plat recording. tho The site plans for East Renton show the northerly road stub for 145 Ave SE which may extend into the wetland buffer and associated setback:within the Rosemont plat. During engineering review for East Renton, a revised road alignment and grading plan shall be provided which demonstrates that road construction within Rosemonte will comply with applicable sensitive area codes. The revised road design and grading plan may result in modification or loss of lots as shown on the preliminary plat. Alternatively, the applicant may seek approval to use buffer averaging as a means to revise the location of the buffer and BSLB to achieve code compliance within Rosemonte. There shall be no direct vehicular access to or from 14Sth Ave SE from those lots which abut it. A note to this effect shall appear on the engineering plans and the final plat. The applicant shall provide a safe walking access to Apollo Elementary School with urban improvements along the west side of 14Sth Ave NE to the existing crosswalk on the north side of SE 117th SI. This improvement includes urban frontage improvements along property frontage of the Plat of East Renton, urban improvements along frontage of Rosemonte and urban improvements north to the existing crosswalk on the north side of SE 11 ih ST. (It is noted that the adjoining plat of Rosemonte will be subject to urban frontage requirements and urban improvements north to the existing crosswalk on the north side of SE 117th ST.) Alternatively, due to the potential need to construct an urban curb and gutter section along the east side of 14Sth Avenue SE (to re-profile 14Sth Avenue SE, and maintain the resultant slope grading within existing right-of-way), the applicant may elect to provide a graded surface on the east side of 14Sth Ave SE to ensure that school-age pedestrians are provided an acceptable-width walkway surface behind the curbing. The walkway shall be designed to the satisfaction of the school district and DOES. Mitigation/Impact Fees 13. The applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either: (1) pay the MPS fee at the final plat recording, or (2) pay the MPS fee at the time of building permit issuance. If the first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All fees required by King County Code 14.75, Mitigation Payment System FILE NO L02P0005 Page 14 (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building permit application. 14. Lots within this subdivision are subject to King County Code 21A.43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shall be assessed and collected immediately prior to the recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shall be allocated evenly to the dwelling units in the plat and shall be collected prior to building permit issuance. Wetlands 15. Preliminary plat review has identified specific requirements which apply to this project as listed below. All other applicable requirements from K.C.C. 21 A.24 shall also be addressed by the applicant. a. The Class 2 wetland shall have a minimum 50-foot buffer of undisturbed vegetation as measured from the wetland edge. b. Sensitive area tract(s) shall be used to delineate and protect sensitive areas and buffers in development proposals for subdivisions and shall be recorded on all documents of title of record for all affected lots. c. . Buffer width averaging may be allowed by King County if it will provide additional protection to the wetland/stream or enhance there functions, as long as the total area contained in the buffer on the development proposal site does not decrease. In no area shall the buffer be less than 65 percent of the required minimum distance. To ensure such functions are enhanced a mitigation plan will be required for the remaining on-site sensitive areas. An enhancement plan shall be submitted for review during engineering review. d. A 15-foot BSBL shall be established from the edge of buffer and/or the sensitive areas Tract(s) and shown on all affected lots. e. To ensure long term protection of the Sensitive Areas a split-railed fence of no more than 4 feet in height shall be installed along the Sensitive Area Tract boundaries in the area of proposed lots. Sensitive Area signs shall be attached to the fence at no less than 100 foot intervals. f. If alterations of streams and/or wetlands are approved in conformance with K.C.C. 21A.24, then a detailed plan to mitigate for impacts from that alteration will be required to be reviewed and approved along with the plat engineering plans. A performance bond or other financial guarantee will be required at the time of plan approval to guarantee that the mitigation measures are installed according to the plan. Once the mitigation work is completed to a DOES Senior Ecologist's satisfaction, the performance bond may be replaced by a maintenance bond for the . remainder of the five-year monitoring period to guarantee the success of the mitigation. The applicant shall be responsible for the installation, maintenance and monitoring of any approved mitigation. The mitigation plan must be installed prior to final inspection of the plat. g. Prior to commencing construction activities on the site, the applicant shall temporarily mark sensitive areas tract(s) in a highly visible manner, and these areas must remain so marked until all development proposal activities in the vicinity of the sensitive areas are completed. FILE NO L02P0005 Page 15 h. During engineering plat review the applicant shall provide a wetland hydrology analysis to demonstrate how the wetland hydrology will be maintained post-construction. i. Detention out-fall structures maybe permitted within the wetland/stream buffers, however, structures shall be located in the outer edge of the buffer, if possible. All buffer impacts shall be mitigated. 16. Development authorized by this approval may require other state and/or federal penmits or approvals. It is the applicant's responsibility to correspond with these agencies prior to beginning work on the site. 17. During engineering review, the plan set shall be routed to the sensitive areas group to determine if the above conditions have been met. Geotechnical 18. The applicant shall delineate all on-site erosion hazard areas on the final engineering plans (erosion hazard areas are defined in KCC 21A06.415). The delineation of such areas shall be approved by a DDES geologist. The requirements found in KCC 21A.24.220 concerning erosion hazard areas shall be met, including seasonal restrictions on clearing and grading activities. Sensitive Area 19. The following note shall be shown on the final engineering plan and recorded plat: RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tracUsensitive area and buffer conveys to the public a beneficial interest in the land within the tracUsensitive area and buffer. This interest includes the preservation of native vegetation for all purposes that benefit the public health, safety and welfare, including control of surface water and· erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tracUsensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tracUsensitive area and buffer the obligation, enforceable on behalf of the public by King County, to leave undisturbed all trees and other vegetation within the tracUsensitive area and buffer. The vegetation within the tracUsensitive area and buffer may not be cut, pruned, covered by fill, removed or damaged without approval in writing from the King County Department of Development and Environmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tracUsensitive area and buffer and the area of development activity must be marked or otherwise flagged to the satisfaction of King County prior to any clearing, grading, building construction or other development activity on a lot subject to the sensitive area tracUsensitive area and buffer. The required marking or flagging shall remain in place until all development proposal activities in the vicinity of the sensitive area are completed. No building foundations are allowed beyond the required 15-foot building setback line, unless otherwise provided by law. FILE NO L02P0005 Page 16 ~------------------------- Other. 20. The plat design shall be revised to provide the minimum suitable recreation space consistent with the requirements of K.C.C. 21A.14.180 and K.C.C. 21A. 14.190 (Le., minimum area, as well as, sport court[s), children's play equipment, picnic table[s), benches, etc.). a. A detailed recreation space plan (i.e., location, area calculations, dimensions, landscape specs, equipment specs, etc.) shall be submitted for review and approval by DOES prior to or concurrent with the submittal of engineering plats. b. A performance bond for recreation space improvements shall be posted prior to recording of the plat. 21. Tract E shall be revised as a tract which is: a) combined with Track F (sensitive area), b) designated as an open space tract, or, c) designated as recreational area, if served by an approved trail (across wetland buffers) extending from the recreational Tract G and functioning as an extension of recreation from Tract G. Plans for the tract -designation and design, shall comply with codes and shall be to the satisfaction of DOES prior to engineering approval. 22. A homeowners' association or other workable organization shall be established to the satisfaction of DOES which provides for the ownership and continued maintenance of the recreation, open space and/or sensitive area tract(s). 23. Street trees shall be provided as follows (per KCRS 5.03 and K.C.C. 21A.16.050): a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. c. If King County determines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right-of-way line. d. The trees shall be owned and maintained by the abutting lot owners orthe homeowners association or other workable organization unless the . county has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DOES if located within the right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or storrn sewers, or that is not compatible with overhead utility lines. f. The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DOES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at (206) 684-1622 to determine if 148th Ave SE is on a bus route. If 148 th Ave SE is a bus route, the street tree plan shall al.so be reviewed by Metro. FILE NO L02P0005 Page 17 SEPA h. The street trees must be installed and inspected, or a performance bond posted prior to recording of the plat. If a performance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year. After one year, the maintenance bond may be released after DDES has completed a second inspection and determined that the trees have been kept healthy and thriving. i. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on the current county fees .. 24. The following have been established by SEPA as necessary requirements to mitigate the adverse environmental impacts of this development. The applicants shall demonstrate compliance with these items prior to final approval. (1.) To mitigate the significant adverse impact the plat of East Renton will have on the intersections of SR 900/148 th Ave SE and SR 900/164 th Ave SE, the applicant shall install, either individually or in conjunction with other development projects in this area, the following improvements at the SR 900/148th Ave intersection: • A traffic signal, and • Eastbound and westbound left turn lanes The design for the SR 900/148 th Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by King County to the extent such improvements are located in County right-of- way). In addition, at a minimum, the existing entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet, respectively) shall not be reduced as part of the intersection improvements. Documentation shall be submitted to show this requirement is met. All construction work associated with the intersection improvements shall be completed between April 1st and September 30 th • This seasonal restriction . shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantee with WSDOT which assures the installation of these improvements within two years of the recording of East Renton. In this event, intersection improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-rata share dollar amount to be paid shall be set by WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip distribution for East Renton • The total trips contributed to the intersection of SR 900.148 th Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P3008), East Renton (L02P0005), Shamrock (L02P0014), Rosemonte (aka lronwood- L03P0018), Martin (L05P0019) and any future land use applications FILE NO L02P0005 Page 18 submitted to King County for which compliance with the King County Intersection Standards (KCC 14.80) is required at either the SR 900/148 th Ave intersection, or the SR 900/164 th Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu of the approach described above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years of the date of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21A.28.060A] (2.) Documentation shall be provided to demonstrate to the satisfaction of WSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900/148 th Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 148 th Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 21A.28.060A] Q. OTHER CONSIDERATIONS: 1. The subdivision shall conform to K.C.C. 16.82 relating to grading on private property. 2. Development of the subject property may require registration with the Washington State Department of Licensing, Real Estate Division. 3. Preliminary approval of this application does not limit the applicant's responsibility to obtain any required permit or license from the State or other regulatory body. This may include, but is not limited to the following: a. Forest Practice Permit from the Washington State Department of Natural Resources. b. National Pollutant Discharge Elimination System (NPDES) Permit from WSDOE. c. Water Quality Modification Permit from WSDOE. d. Water Quality Certification (401) Permit from U.S. Army Corps of Engineers. R. ATTACHMENTS: 1. Preliminary Plat Map 2. Renton Sewer Availability letter 3. Road Variance/ L03V0049 4. Surface Water Management Variance/ L02V0089 5. Surface Water Management Variance/ L04V0103 6. Density Calculation Worksheet 7. Recreation cross section for Tract G (previously labeled Tract C) FILE NO L02P0005 Page 19 S. TRANSMITTED TO PARTIES LISTED HEREAFTER: ANDERSON, ROBERT L. , PO BOX 353 MAPLE VALLEY, WA 98038 CAM WEST DEVELOPMENT RALPH HICKMAN 9720 NE 120TH PL, #100 KIRKLAND, WA 98034 CHILDS, R. KRISTINE & KEITH, 12004 -148TH AVE. SE RENTON, WA 98059 CLAUSSEN, KIM SR. PLANNER, DDESI LUSD MS: OAK -DE-0100 DALRY, MIKE, 11524 -148TH AVE. SE RENTON, WA 98059 DINSMORE, LISA CURRENT PLANNING SUPERVISOR DOES 1 LUSD MS: OAK -DE-0100 DONNELLY, CLAUDIA, 10415 147TH AVE SE RENTON, WA 98059 DYE, PETE PRELIMINARY ENGINEER, DOES ILUSD MS: OAK -DE 0100 GILLEN, NICK WETLAND REVIEW, DOES 1 LUSD MS: OAK -DE-0100 GOLL, SHIRLEY CURRENT PLANNING SECTION, DOES 1 LUSD MS: OAK -DE-0100 GRAVES, JOHN LOZIER HOMES CORPORATION 1203 -114TH AVE.SE BELLEVUE, WA 98004 KC HEARING EXAMINER'S OFFICE, ATIN: MARKAIGINGER MS, YES-CC-0404 LANGLEY, KRISTEN LAND USE TRAFFIC REVIEW DOES 1 LUSD MS: OAK -DE-0100 LIND, REBECCA CITY OF RENTON EDNSP DEPT. 1055 S. GRADY WAY RENTON, WA 98058 SCHARER, KAREN PROJECT MANAGER II, DDES/LUSD MS: OAK -DE-0100 SEA TILE KC HEALTH DEPT E ENVIRONMENTAL HEALTH 14350 SE EASTGATE WAY BELLEVUE WA 98007 SLA TIEN, SARA CAM WEST DEVELOPMENT 9720 NE 120TH PL #100 KIRKLAND, WA 98034 TOWNSEND STEVE SUPERVISOR, LUIS DOES MS OAK DE 0100 TRIAD ASSOCIATES, 11814 115TH AVE NE KIRKLAND, WA 98034 WEST, LARRY GEO REVIEW, DDES 1 LUSD MS: OAK -DE-0100 WHITING, KELLY, KC DOT RD SERV DIV MS KSC-TR-0231 WHITIAKER BRUCE SR ENGR, ERS/LUSD MS OAK DE 0100 CORE DESIGN INC., 14711 NE 29TH PL, #101 BELLEVUE, WA 98007 CRULL, RICK & DEBRA, 11813 148TH AVE SE RENTON, WA 98059 EGGERT, URSULA, 15520 SE 116TH ST. RENTON, WA 98059-6014 ZIMMERMAN, GREGG CITY OF RENTON PLANNING 1055 SOUTH GRADY WAY RENTON, WA 98055 12/21/2006 AM FILE NO L02P0005 Page 20 r 1 o I I :--_ .. ", , i , .-'- . -;~~~'~~-_=::,,:,'3;:-_ ~f } , ..... ,_ .. , ~ --. . .. i I! ,. i .il ,-, -, --E'" !? ;-_,' •. _ -; -"1-· {; -_.1-.-1 . , , ,---, , , , '-1----...,. -1- " if !t -' : 'I " Ii ,I L __ --.! , "I "I I ~! ! 'r----~-...I... -. -I-_ , '--___ --l ____ ..: 1111 I i I T CAMWEST DEVELOPMENT EAST RENTON KC, L02P0005 KINO COVNTY, WASHINOroN .. ~ " m o ~ ... iii z m I /II!!I \-:-~/ ull' , l ~ ~ L02P0005 ATTACHMENT 1. Preliminary Plat Map I o~ Z. ""'t~1I>lf'""'_ "\_ ...... '°',..'10 .. _'_-." ........ _'., .. ,, .. , ... .-----r--T---'---C~r.------f-~~----,- ~. o i ! I II 'I ' ' a I () B. " t ~ ;~ ." '1 ·T.· I. '~. 'I ••• ~ -"'\ ". -.. "1 ...... ,. ." .----------........ ,-----.. -... ~ -,- , " -,~~<:-.~" : f~F . . " , ' ... '. ','. ICING COUNTY, L02P0005 ATTACHMENT 1. Z.J ~ . ~:. '\.: . .\. . f .. ~"" '. I·' . ' .. ' ':".-':1 : :: ,~ . .. ' ' '! . " .. PRELIMINARY UTILITY PLAN KING COUNTY R.4 LA YOUT CAAfWEST DEVELOPMENT ""'" - " ... : . ..,.. .. ,--' ..... EAST RENTON WAIIHINQTON 11 11; Ii \-:-~/ "II' , r I !:. . r J esse Tanner, Mayor March 28, 2002 Sara Slatten Carnwest Development 9720 NE 120'h Place, Suite 100 Kirkland, W A 98034 CITY 'IF RENTON PlanningIBuilaJllgiPublicWorks Department -Gregg Zimmerman P,E" Administrator RECElveo APR 1 72002 LAN~~~{OSUENTY RVICES SUBJECT: SANITARY SEWER AVAILABILITY -EAST RENTON PROPERTY KCPID NO 102305-9017,9023 PROPOSED 68 LOT PLAT This letter shall serve as a supplement to the sewer availability form prepared for the subject site _ dated March 28, 2002. The City oj Renton can provide sanitary sewer service to this proposed development as submitted to the City on July 26,2001 and as indicated on the preliminary plat drawing prepared by Triad and Associates with a production date of August 13, 2001. This submittal meets the City's basic criterion for zoning and land use required to receive sewer availabilIty. Sewer service to this proposed plat may come from two different portions of the City's system. The first alternative would be for this development to flow to the south and connect to the City's East Renton Interceptor system. Another option would be for the development to flow to the north into the City's Honey Creek system, The exact means for service to be provided will be determined as you proceed with the platting process. As you are aware, the methodology may also be predicated upon when the adjacent properties proceed with development. This sewer availability is also condition~:d upon the requirement that a covenant to annex document be executed prior to the issuance of any City permits for the installation of sewer to serve this plat. The format of this document is currentlybeing developed by the City and-will be- forWarded to you upon its completion. Fees for this plat will include System Deyelopment Charges-of $760.00 per lot, Special Assessment District charges foreither the East Renton or Honey Creek Systems; $60 per lot side sewer permit fees, right-of,way fee and bond to be detennined upon submittal, inspection and plan review fee of 5% of estimated construction cost, and a King County permit fee equal to 100% of costs billed by the County to the City. If you ha_v_e ___ " quesl.i<>ns're,g this availability, please contact me at (425) 430-7212. cc: Rebecca Lind, EDNSP ~ __ ~H.-D~!~y~IS~IQ~N~S~a~IT~!~IIuT~IF~S~/D~Q~C~Sua~QQ~2~·1~93wd~6~d~DM~('~'lf ______________ ~ ____________ ~-E 1'l rr' ~ 1055 South Grady Way· Renton, Washington 98055 ® This paper contains 50% reC~cled material, 30% post consumer AHEAD OF THE ,cURVE L02P0005 ATIACHMENT 2. Renton Sewer Availability letter / ® 'King County' Road Services Division Department of Transportation 201 Southlackson Street Seattle, WA 98104~3856 October 20, 2004 CamWest Development C/O Chris Bicket, P.E. P.O. Box 65254 Seattle, WA 98155 RE: Road Variance L03V0049:'" East Renton Property Plat -Related File L02P0005 Dear Sir!M:adam: Thank you for submitting your application for a road variance from the King County Road Standards (KCRS). You requested a variance 'from Section 2.12 of the KCRS concerning the stopping sight distance (SSD) along the plat frontage on 148 th Avenue SE. 148 th AvenueSE is a collector arterial with posted speed limit of3 5 MPH. The original proposal to match the curb and sidewalk section to the existing vertical alignment has been revised to a 620-foot vertic,al crest curve that will 'lower the alignment by up to 3.5 feet and improve SSD. The revised design will utilize the two~foot target criteria in the American Association of State Highway and Transportation Official's (AASHTO) manual, The proposal will provide 455 feet of SSD along the crest curve that will meet KCRS with a downgrade correction for the average 6% grade. r approve a variance to allow the 620-foot ,vertical cUrve with 455 feet of SSD, utilizing a two-foot target. The slight grade break (under 1%) at the north end of the vertical curve is also acceptable. No variance is required for the vertical crest curve 400 feet to the west of the site bec:ausethe SSD meets KCRS approaching the west property line. A copy of the staff's analysis, findings and conclusions is enclosed. If you have any questions, please call Craig Comfort, Road Variance Engineer, Traffic Engineering Section, at 206"263-6109. ~er~IYlii .~ '\ ' <--..~/U~.47\~ Paulette Norman, P.E. County Road Engineer PN:CC:kc ,e. L02P0005 ATTACHMENT 3. Road Variance/ L03V0049 ® King county Department of Development and Environmental Services 900 Oakesdale Avenue SW Renton, WA 98055-1219 December 19, 2002 CamWest Developmen~ 9720 NE 1201ll Place Suite 100 Kirkland, W A 98034 Todd A. Oberg, P.E. Triad Associates 11814 -115th Avenue NE Kirkland, W A 98034 RE: East Rentop Subdivision ,\CSWDM AdjustmentRequest (file No. L02VOO89) Dear Applicant and Engineer: The Land Use Services Division, Engineering Review Section, has completed review of the adjustment request for the East Renton subdivision. You are requesting approval for an adjustment from the 1998 King COWlty Surface Water Design Manual (KCSWDM) Core . Requirement No.1, Section 1.2.1, Discharge at the Natural Location. Our review of the infonnation and a site visit provides the following findings: 1. The proposed East Renton subdivision is located on the west side of 148m Avenue SE at SE 120th Street. The 66101, 19.6 acre, proposed East Renton subdivision is filed tmder Lan~ Use Servic~s Divisioll.(LUSD) file number L02P0005. 2. The East Renton subdivision is located in the Honey (Dew) Creek subbaSin of the May 'Creek basin. The site is subject to the Level Two flow control and Basic water quality requirements of the 1998 KCSWDM. 3. The large, rectangular site oriented in an east-west direction is characterized by an upland area to the east adjacent to 148th Avenue SE and a low, wetland area to the west. The lower, western area contains two hawks nests and associated buffers within the wetland area that" encompasses two separate drainage paths that cross the north property line through existing culverts. The developable, eastern portion of the site containS a low ridge that traverses that portion of the site from northwest to southeast. The southwest portion sheetflows to the wetland area to the west and. the northeast portion sheetflows across the north property line onto the adjacent parcel. All drainage paths converge on the adjacent parcel to the north and form the headwaters to Honey Creek that flows north. At least a quarter mile downstream, Honey Creek eventually turns west just to the south ofSR900. TI;le western side of 148th Avenue SE is the only upstream area that contributes flow to the site. I East RentonfL02V0089 December 19, 2002 Page 2 aD 4. The proposal is to collect most runoff from the projeCt site and direct it to a single detention and water quality facility located in the north central portion ofthe site_ The allowed releases would then be dispen:ed to the wetland/stream buffer area. Nuisance flows across the north property line would be significantly curtailed. ConceptUal drainage plans show that frontage improvements are included in the storm drain system. 5. No decorative ponds or shalIow wells have beeri identified th~t would be affected by the proposed diversion. -6. The Level One Drainage Analysis did not identify any restrictions or problems associated with the proposed discharge location or downstream path. 7. A consolidation of facilities for the proposed subdivision will be more economical in long term maintenance. . Based on these fuidings, we hereby approve this adjustment to allow the diversion ofrunofr"to a single facility draining to the onsite wetland/stream buffer area with the following conditions: . 1. The release rates for" the detention facility will be based on the tributary area being directed to the facility . 2. The volume for the detention facility ~ilI be based on all flows directed to the facility at full development under current zoning. The allowed release rate will be reduced by any undetained flows that would bypass the proposed subdivision drainage facilities. The detention volume shall be sized using the-Level Two flow control standard in the 1998 KCSWDM, A 10 to 20 percent volumetric factor of safety must be applied to all storm events requiring detention. The design Technical Information Report shaH state the factor of safety selected and the basis of that detennination. 3. Water quality facilities must be sized based on the entire proposed subdivision draining to the facilities including any required frontage improvements. 4. All onsite or offsite drainage facilities must be located in a public right-of-way or -storm drainage tract dedicated to King COWlty. 5. Additional storm drainage requirements identified by SEPA or the plat hearing review will apply to this projec.t. If you ·have any further questions regarding this KCsWDM adjustment or the design requirements, please contact Mar~ Bergam at (206) 296-7270. r\Y'4'3A1 . LJY'1t!~ James Sanders, P.E. Development Engirieer . Engffieering Review Section .Land Use Services Division ~ Supervising Engineer Site Engineering arid Planning,$ection Building Services Di~Sion - cc: . Curt Crawford, P.E., Managing Engineer, Stormwater Services Section, KCDNR Randall Parsons, P.E., Senior Engineer, Engineering Review Section, LUSD Pete Dye, P.E., Senior Engineer, Engineering Review Section., LUSD Lanny Henoch, Planner n, Current PlanDing Section., LUSD Mark Bergam, P.E., Senior Engineer, Engine~~ng Review Section, LUSD ---~ C OJ ·C OJ > -C w E w OJ OJ C OJ ~ '-W -OJ S~ WO 00 ~~ :JO U)--J "" ~ Z UJ l[)::2: OI 00 ~~ N~ O~ --J~ ® King CoUnty Department of Development and Environmental Services 900 oakesdale Avenue &N Renton. WA 96055-1219 March 24,2005 Sara, Slatten Cam West Development 9720 NB 120· Place #100 JCUkland; IVA 98034 Rebecca S. Cushman, P.E. Triad Associates 11814 -IlSIh Avenue NE Kirkland, viA 98034 RE: . East Renton SubdiVision 1998 XCSWDM Shared Facility Plan: DOES Project File No. 'L02POO05 and Adjustment File No. L04VOI03 . Dear ApplicaiJ.t and En~ineer: The Land Use Services Division, EngUieerhtg Review Section, has completed review of the Shared Facility Plan request for the East Renton and adjoining Rosemonte subdivisions.· This request addressei the 1998 King County SurfaCe Water Design Manual (Kcswm .. f), Special Condition No.1, Section 1.3.1, Other Adopted Area-Specific Requirements and the Shared Facility Plan Gnideimes published in a memo dated September"IS, 1999 describing the Shared Facility Plan approval process. Our review of the preliminary plat plans provides the following findings:' I. The East Renton subdivision is ioeated on the east side of 148 111 A venue SE at approximately SE 12<fh Street The 66101, 19.6 acre, East Renton subdivision is IDlaergoing preliminary review under LUSD file D\UUber L02P0005. The East Renton subdivision had-previously processed 1998 KCSWDM adjustment L02V0089 for a dh-en;ion to consolidate subbasin flows_ into a single, on-site facility. 2. The proposed Rosemonte subdivision is located adjacent to East Renton along the north property line. The 41 lot, 14.7 acre Rosemonte subdivision is also undergoing. preliminary approval under LUSD file nwnber L03POO18. At this time, CamWest (develoPer of~ Renton}is in ne·gotiation to purchase the eastern portion of Rosenionte. The developer of Rosemonte is also in negotiation with the City of Renton to ~ex the western portion of Rose monte into the city. 3. The East Renton and Rosemonte subdhisions are located in the Honey Creek subbasin of the May Creek basin. Both sites are subject to the Level "One flow control and Basic ~teiquality requirements of the 1998 KCSWDM. 4. The proposal is to officially acknowledge the accommodation of the oortheasJ portion of the East Renton subdivision that is naturally tributary to the north property line into East RentonIL02P0005 and l,-osemontefL03POOl8 MarcQ. 24.2005 Page 2 of3 the shared facility design ·ofthe Rosemonte subdivisIon. This approach would abandon the diversion adjustment (LO~V.0089) previously processed that would have· diverted flows from this fl!Ca into the East Renton's on-site. drainage facility. 5. If CamWest purchases the easte.m portion of Rosemonte; as previously indicated, then . these two projects, could be designed and reviewed con~urrently. Construction could .. then either occur concurrently or in phases with. the understanding that the shared drainage .facility would be constructed before the d?velopment of the two contribu~g portions of each site. If the two-projects remain with separate applicants, the shared drainage faeilfty in the Rosemonte subdivision would sti~ need to be constructed-first t9 its final configuration. . 6. A consolidation of facilities for the proposed subdivisions will be more economical in long term maintenance. Based on'these [mdings. we hereby approve this request for a shared drainage facility with -shared facility plan for the East Renton and Rosemonte subdivisions with the following conditions: 1. The developer of the shared drainage facility is responsible for any cost sharing agreemel).ts that may need to be set up as part of the implementation of the shared focility pian. 2. Engineering plans for both the East Renton and Rosemonte subdivisions shcl! note tm:; approved shared facility plan. 3. If the two projects are phased separately in time, the shared drainage facility must be constructed flist and operational before any lots tributary to the facility can be recorded. .4. If there is a change of design standards or project design that requires modification of . the shared facility design. an update to the shared facility plan' shall be provided as part Of the trailing project's engineering review submittal. If you have any further questions regarding this KCSWDM Shared Facility Plan approvaJ or its conditions, please contact Mark: Bergam at (206) 296-7270. Sincerely, ~. James Sanders, P.R Development Engineer Engineering Review Section Land yse Seivices Division . ~ Supervising Engineer Site Engineering and Plarming Section Building Services Division m u c ro ·C ro > ..... C 0) E 0) Ol ro c ro ~ .... 0) ..... ro S c;t) o 0)..- UO 00> 't:-q- :::JO (f)....! l!) ~ Z LU L()~ OI o 0 0 a..« ~l= .....J« ® King County . Department of Development and Environmental Services land Use Services Division 900 Oakesdale Avenue Southwest Renton, Washington 98057-5212 206-296-0000 TTY 206-296-7217 Web date: 0912712006 g~BIilIVlsI0Ni;}eNSITY & DIMENSr0NC,6Il::CIDLA'FrONS For alternate formats, call 206-296-6600, File Number (To be filled in by DDES) CPRELIMINARY SUBDIVISION WORKSHEET RELATING TO DENSITY AND DIMENSIONS Several development regulations playa role in the creation of a sUbdivision within King County'. Determining the allowable density, minimum density, and a lot width on a piece of property can be confusing. This worksheet will assist you in correctly applying specific portions of the code and will be used to detennine if a proposed subdivision or short subdMsion meets the density and dimensions provisions of the King County Zoning Code (Title 21A). This worksheet is designed to assist applicants and does not replace compliance with adopted local, state and federal laws. . Pre-application conferences are required prior to submittal of a subdivision or short subdivision. These' conferences help to clarify issues and answer questions. They may save you both time and money by eliminating delays resulting from requests for additional information and revisions. You may call 206-296-6600 to find out how to arrange for a pre-application conference. WO~'heet P,epaced By: Me) -shiou L'", / T Y'i~d ASS<lC1'~ie5 Date: 12/ 18/v>o r, (P~ntNama) Subdivision Name: C:4:St ~ Comprehensive Plan Land Use Designation: c;, ~ I.e -b~~/., f1.vd,uYV\ '1-/2-bl.J/,4C" ---~ Zoning: R-4- If more than one Comprehensive Plan Land Use designation or zone dassification exists for the property, show the boundary between the land uses or zones and the area within each on the preliminary plat map. if a single lot is divided by a zone boundary, transferring density across zones on that lot may be pennitted subjecllo the provisions of KC.C. 21A.12.200. PLEASE COMPLETE ONLY THE APPLICABLE PORTIONS OF THIS FORM I. Site Area (K.C.C. 21A.06.1172) also see (K.C.C, 21A.12.080): Site area ~n square feet} is the TOTAL hO.rizontal area of the project site. CalcUlation: --:C----=-::-7-Gross horizontal area of the project site 740 8/? fa Site area in square feet NOTE: To continue calculations, convert site area in square feet to acres by dividing by 43,560 I 7· 0 I Site area in acres NOTE: When calculating the site area for parcels in the RA Zone, if the site area should result in a fraction of an acre, the foliowing shall apply: Fractions of .50 or above shall be rounded up to the next whole number and fractions below .50 shan be rounded down. Example: If the site area in acres is'19.5 acres (less the submerged land and less the area that is required 10 be dedicated on the perimeter of a project site for public right-of-way) the site area can be rounded up to 20 acres. No further rounding is allowed. (See K.C.C. 21A. 12.080) II. Base Density (K.C.C. 21A.12.030 -.040 tables): The base density is determined by the zone designations(s) for the lot. -4 du/acre III. Allowable Dwelling Units and Rounding (K.C.C. 21A.12.070): The base number of dwelling units is calculated by multiplying the site area by the base density in dwelling units per acre (from K.C.C.21A 12.030 -.040 tables). ! 7, {} ! site area in acres (see Section 1.) X 4 base derlsit'l (see Section fl) &; f2 allowable dwell!ng units Except as noted below, when calculations result in a fraction, the fraction is rounded to the nearest whole number as follows: A. Fractions of .50 or above shall be rounded up; and B. Fractions below .50 shall be rounded down. NOTE: For parcels in the RA Zone, no rounding is aJlowed when calculating Ihe allowable number of dwelflng units. For example, If the calculation of the number of dwelling units equaled 2.75, the result would be 2 dwelling units. Rounding up to 3 is not allowed. (See K,C.C. 21A.12.070(E).) IV. Required On-site Recreation Space (K,C.C. 21A.14.180): This section must be completed only if the proposal is a residential development if more than four dwelling units in the UR and R zones, stand-alone townhouses in the NB zone on property designated Commercial Outside of Center if more than four units, or any mixed use development if more than four units. Recreation space must be computed by multiplying the recreation space requirement per unit type by the proposed number of such dwelling units (K.C.C. 21A.14.1BO). Note: King County has the discretion to accept a fee in lieu of all or a portion of the required recreation space per K.C.C. 21A.14.185. Apartments and town houses developed at a density greater than eight units per acre, and mixed use must provide recreational space as foHows: 90 square feet X 170 square feet X 170 square feet X _____ proposed number of studjo and one bedroom units _____ proposed number of two bedroom units + proposed number of three or more 'bedroom unils + Recreation space requirement -Q) Q) ..r::. CJ) ~ '-0 S c 0 :;::: <Il ::J () <Il () £N tJ) a5 ''"1; 0 <0 I- Z W I.O~ OI ,0 () ,0 'a.. « 2)1= ....J« Required On-sita RaGteation Space Continued Residential subdivisions, townhouses and apartments developed at a dens'ty of eight units or less per acre must provide recreational space as follows: 390 square feet X 17ft, proposed number of units 2:>.74-0 5F Mobile home parks shall provide recreational space as follows: 260 square feet X proposed number of unlts V. Net Buildable Area (K.C.C. 21A.06.797): This section is used for computing minimum density and must be completed only if the site is located in the R-4 through R-4B zones and designated Urban by the King County Comprehensive Plan. The net buildable area is the site area (see Section I) less the following areas: ____ tJ=_. areas!'illht!l a project site which are required to be dedicated for public rights-of-way in excess of sixty {601 of width + 197, b8't critical areas and'thelr buffers, to the extent they are requited by King County 10 remain undeveloped + {) areas required for above ground storrnwater control facilities including, but not limited to. retentionJdetefllion ponds, blofiltra\ion swales and setbacks from such ponds and swale~ + Z5:', 740 areas required by King County to be dedicated Of reserved as on-site recreation areas. Deduct area within stonnwater control facility if requesting recreation space credit as allowed by KC.( 21A.14.1BO (see SectIon IV) + !2...-. regional utility corridors, and + ___ --'0,,-other areas, excluding setbacks, required by King County to remain undeveloped z,2--3;4z.4' Total reductions Calculation: 740,g-rlO site area in square feet (see Section1) Total reductions U3,4-Z;1 ,:17 +,-z Net buildable area in SQuare feet NOTE: convert sile area is square feet to II ~ 88" Net buildable area in acres acres by dividing by 43,560 VI. Minimum Urban R~idential Density (K.C.C. 21A.12.060): The minimum density requirement applies 2n!:i to the R-4 through R-48 zones. Minimum density is detennined by multiplying the base density in dwelling uni~s per acre (see Section II) by the net buildable area of the site in acres (see Section V) and then multiplying the resulting product by the minimum density percentage from the K.C.C. 21A.12.030 table. The minimum density requirements may be phased or waived by King County in certain cases. (See KC.C. 21A.12.060.) Also, the minimum density requirement does not apply to properties ioned R-4 located withIn the rural town of Fall City. (See KC.C. 21A 12.030(8)12.) Calculation: ~ base density in dulac (s~ Section II) X II, if Net buildable area in acres (see Section V) 4= 7·sz. X minimum density % set forth in K.C.C. 21A.12.030 or as adjusted In Section VII ____ minimum dwelling ,-nits required . (!5) .. •.• ~ ___ ~~ .. _. __ .. _~ ... _.If.7 ... _ ....... _ ._ VII. Minimum Density Adjustments for Moderate Slopes (K.C.C. 21A.12.0B7): Residential developments in the R-4, R-6 and R-8 zones may modify the minimum density factor in K.C.C. 21A. 12.030 based on the weighted average slope of the net buildable area of the site (see Section V). To determine the weighted average slope, a topographic'survey is required-to ca\pulate the net buildable area{s) within each of the following slope increments and then multiplying the number of square feet in each slope increment by the median slope value.o.f each slope incre!llent as follows: , _____ sq. ft 0-5% slope increment X 2.5% median slope value = _____ sq. ft 5-1 0% slope increment X 7.5% median slope value = , + sq. ft 10-15% slope Increment X 12.5% median slope value = -----+ + sq. ft 15-20% slope inctement X 17.5% median slope value '" -----+ + sq. ft 20-25% slope increment X 22.5% median slope value = -----+ + sq. ft 25-30"ho slope increment X 27.5% medIan slope value '" + + sq. ft 30-35% slope increment X 32.5% median slope value = + + sq. ft 35-40% slope Increment X 37.5% median slope value = , _____ Tolal square feet in net buHdable area Total square feet ------adjusted for slope Calculation: lolal square feet adjusted for slope divided by total square' feet in net buildable area -===== weighted average slope of net buildable area _ % (Note: multiply by 100 to convert to percent -round up to nearest whore percent) Use the table below to detennine the minimum density factor. This density is substituted for the minimum density factor in K.C.C. 21A.12.030 table when calculating the minimum density as shown in Section VI of this worksheet Weighted Average Slope of Net Minimum Density Factor Buildable Area(s) of SUe: 0% -less than 5% 85% 5%-lessthan 15% 83%, less 1.5% each 1% of average slope in excess of 5% 15% Jess than 40% 66%, less 2.0% for each 1% of average slope in excess of 15% EXAMPLE CALCULATION FOR MINIMUM DENSITY ADJUSTMENTS FOR MODERATE SLOPES: + + + + + + + --,:oc=-sq. ft 0-5% slope increment X 2.5% median slope value '" sq. ft 5-10% slope increment X 7.5% median slope value = sq. ft 10-15% slope Increment X 12.5% median slope value = _____ sq. ft 15-20% slope Increment X 17.5% median slope value '" -===== sq. ft 20-25% slope increment X 22.5% median slope value = _ sq. ft 25-30% slope increment X 27.5% median slope value = _____ sq. ft 30-35% slope increment X 32.5% median slope value '" --o;=c:--sq. ft. 35-40% slope ina-ement X 37.5 % median slope value = 30,000 Total square ~eet in net buDdable area 750 + 2,500 + ----+ ----+ ===: --cc=o-+ 3,250 Total square feet 'adjusted for slope 3,250 Total square feet adjusted for slope' divided by 30,000 Total square feet in net buildable area .108333 Weighled average slope of net buildable area ___ '~I~%,-o (Note: multiply by 100 to convert to percent -round up to nearest whole percent) Using the labte above, an 11% weighted average slope of net buildable area falls within the 5% -less than 15% range which has a mlhimum density factor of 83%, less 1.5% for each 1 % of average slope in excess of 5%. Since 11% is 6% above 5%, multiply 6 Urnes 1.5 which would equal 9%. Subtract 9% from 83% for an adjusted minimum density factor of 74%. This'replaces the minimum densIty factor In K.C.C. 21A.12.030 table . <::.,~.~",,",,"O!l"""'" ""...-l. ........ a~ ..... ..... Q) Q) ..c If) .::s! L- 0 5: c 0 'ro :::J U Cii U ~~ "If) 55~ 0 CD I- Z UJ LO~ .0:1: '0 O~ ;~ l= '0 ....J<{ N '-., Z-d " ,j.:.~> .. '--, . .... "\ ..... .~i~ I) '.' .. a \ .O'L9t ~4· r I . . . . :.' ' . r., ~v .. .:' .. , , ~~ ,0 & . ( '\. ~"\,,,:p · . c$ ~ ~~." , · ";'0~ ~. ~~'V. 'W rt· ·,·tD '. , . ..~. . . [ .. " .. ' " , '.;r .. ' L'09t 'i.!; . , j" ~. '<t-I -\. · c:-' i~ I ~ I , '" . , \1 .2.-. iC'i , . ~ •• g .' \ --~ ..... :5 j:::; 4' :;:: ,~ E n'!i" .. ~ ,~ 3' \ 'a ':' Lu lli .1-Il::: '<.J I~ ~. :<C' .'.'- ~,~ ~', .C"\ i~ ~ . .aJ \~ !; , llJ i C .1 . . '. \ .\ 9'9#'#' \ \ 1\1 \ , . " ' \ , \ .~ ~ .~ c i f: 6f:Y ~ It) L02P0005 ATTACHMENT 7. OOZE: .l3r1:l3SHi dH WdSE::t ZOOZ Recreation cross section for Tract G (previously labeled Tract C) OZ d3S -- j , J' .... -' , ., , . ' - ',. L , ~ '*, • \ ............ \' . , .... f . , , .' . , . ~ 'f ... - ~. ~ '. • ,.,fI~' ~.r: N_-· ... · .. ~ ...... ~ .. -",",,-" \ ... , " , , ' . \1 _. r .~,l. .• _ •.• ot/"-. ....... ~_""."lf" .. . ~"J~I·· , I 1 t ~I ,0 1 '. ~ :-.. ... '\ .~. -.. -;..~.- ...... ,-";... .. ~~.-.. • . I' ~., . f,; t:O ;:,t: I( .ft. ... ' ;" ~ ~" ~. '. • '.ir ~. j --.. DO Sr::<~~~~<~~:J ~h <: c.... 0 0 nurpCWtl'3~rnu I p ::T II 8 ::J t if ~ i (J) f ;; (1) K ~ § : J I ::J f (1) ~ i ---~------------------------------------------------------ L02P0005 Bruce Whittaker DDES/LUSD MS OAK-DE-0100 REPORT AND DECISION OFFICE OF THE HEARING EXAMINER KING COUNTY, WASIllNGTON 400 Yesler Way, Room 404 Seattle, Washington 98104 Telephone (206) 296-4660 Facsimile (206) 296-1654 Email: hearex@metrokc.gov April 5, 2007 SUBJECT: Department of Development and Environmental Services File No. L02P0005 Proposed Ordinance no. 2007-0010 EAST RENTON Preliminary Plat Application Location: West of 148th Avenue Southeast at approximately Southeast 120th Street, Renton Applicant: CamWest Real Estate Dev., Inc. represented by Robert Jobns, Attorney lohns Monroe Mitsunaga 1601 - 1 14th Ave. SE, # 110 Bellevue, Washington 98004 Telephone: (425) 467-9960 Facsimile: (425) 451-2818 King County: Department of Development and Environmental Services (DDES) represented by Karen Scharer 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 Telephone: (206) 296-7114 Facsimile: (206) 296-7051 SUMMARY OF RECOMMENDA TIONSIDECISION: Department's Preliminary Recommendation: Department's Final Recommendation: . Examiner's Decision: EXAMINER PROCEEDINGS: Hearing Opened: Continued for Administrative Purposes: Hearing Closed: Approve subject to conditions Approve subject to conditions (modified) Approve subject to conditions (modified) March 22, 2007 March 22, 2007 March 23, 2007 L02P0005-East Renton 2 The public hearing on the proposed subdivision of East Renton was conducted concurrently with the public hearing on the proposed subdivision of Rosemonte (DDES File No. L03POOI8). Participants at the public hearing and the exhibits offered and entered are listed in the attached minutes. At 12:31 p.m. the hearing was continued for administrative purposes, to allow for the submission of proposed exh. no. 29, that would set forth the final recommendation ofthe department concerning revisions to recommended conditions #'s 6, 20, 21 and 22. Exhibit 29 was received by the Hearing Examiner on March 22, 2007, and the hearing was declared closed on March 23, 2007 A verbatim recording of the hearing is available in the office of the King County Hearing Examiner. ISSUES AND TOPICS ADDRESSED: • • • Future development tract Red-tailed hawks nest Safe walking conditions SUMMARY: • • • Recreation area Wetland buffers Surface water drainage The proposed subdivision of 17.01 acres into 66 lots in the urban area is approved subject to conditions. FINDINGS, CONCLUSIONS & DECISION: Having reviewed the record in this matter, the Examiner now makes and enters the following: FINDINGS: I. General Information: Developer: Engineer: STR: Location: Zoning: Acreage: Number of Lots: Density: Lot Size: Camwest Real Estate Development, Inc. 9720 NE 120'" Place, Suite 100 Kirkland, W A 98034 Contact: Sars Slatten 425-825-1955 Triad Associates 12112 115'" Ave NE Kirkland, W A 98034 Contact: Gerry Buck 425-821-8448 10-23-05 West of 148'" Ave SE at approximately SE 120'" St. Parcel -1023059023 R-4 17.01 acres 66 Approximately 3.9 units per acre Approximately 5,000 square feet in size ·. . L02P0005-East Renton Proposed Use: Sewage Disposal: Water Supply: Fire District: School District: Single Family Detached Dwellings City of Renton Water District # 90 City of Renton Issaquah School District Complete Application Date: April 17, 2002 3 2. Except as modified herein, the facts set forth in the King County Land Use Services Division's preliminary report to the King County Hearing Examiner for the March 22, 2007, public hearing are found to be correct and are incorporated herein by this reference. The LUSD staff recommends approval of this subdivision, subject to conditions. 3. Development of this subdivision may affect, and lead to the abandonment of, a red-tailed hawks nest on the subject property. The red-trail hawk is not an endangered or threatened species, and no protection of the red-tail hawk is afforded by law or the King County Code within the designated urban area of King County. 4. The applicant has proposed the establishment of Tract E as a "future development" tract. DDES determined that there is no reasonable access available to Tract E that would not cross wetlan'd or wetland buffer. At the hearing the applicant abandoned its request to designate Tract E as a "future development" tract, and proposes to establish that tract as recreation area, to be connected by trail with the designated recreation/detention Tract G within this subdivision and adjacent to the proposed plat of Rosemonte. 5. The applicant has submitted a revised recreation plan for this subdivision and the adjacent plat of Rosemonte (exh. 26). This plan provides adequate area within Tracts C, G and E and within the proposed recreation tract and trail within Rosemonte to serve these plats jointly with well conceived amenities for recreation and open space, consistent with the requirements of the King County Code. To the extent that a portion of the recreation area necessary to meet the requirements for the plat of Rosemonte is located on the East Renton property, that can be corrected by boundary line adjustment or recording the two plats as a single plat, ifDDES determines that it is necessary to do so. 6. Wetland buffers within this subdivision will need to be modified, utilizing the buffer averaging provisions of the critical areas code, to accommodate the proposed alignment of 145th Avenue Southeast in the vicinity of the north property line, and adding buffer to mitigate the impacts of the proposed trail corridor within Tract F (between Tracts E and G), in accordance with the provisions ofKCC 21A.24.045.D.47.b. 7. The proposed subdivision will provide for safe walking conditions for students who will walk to Apollo Elementary School on southeast I 17th Street by constructing urban improvements to 148th Avenue Southeast from the plat to Southeast 1 I 7th Street. A school crosswalk (crossing 148th Avenue Southeast) is located on the north side of Southeast 1 I 7th Street, where an existing walkway is used by students to travel along the north side of Southeast I I 7th Street east from 148th Avenue Southeast to the school. This crosswalk also serves students walking from the area north of Southeast I 17th Street. Consequently, the crosswalk should be maintained on the L02POOOS-East Renton 4 north side of Southeast I I 7th Street unless it is physically impractical to do so because of constraints resulting from the topography within the right-of-way for 148th Avenue Southeast, south of Southeast I I 7th Street. If those constraints preclude extending curb, gutter and sidewalk from the plat of East Renton to the north side of Southeast I I 7th Street, the crosswalk can be relocated to the south, and improvements made on the east side of 148th Avenue Southeast to Southeast I I 7th Street. 8. The conceptual review of drainage plans has shown that there are no downstream impacts likely to occur from development of the subject property if Level I flow control and basic water quality treatment improvements are designed and constructed in accordance with the 1998 King County Drainage Manual. The final drainage plan will include calculations to assure that the capacity of drainage facilities and discharge rates will be consistent with those flow control standards. CONCLUSIONS: I. If approved subject to the conditions recommended below, the proposed subdivision will comply with the goals and objectives of the King County Comprehensive Plan, subdivision and zoning codes, and other official land use controls and policies of King County. 2. If approved subject to the conditions recommended below, this proposed subdivision will make appropriate provision for the public health, safety and general welfare, and for open spaces, drainage ways, streets, other public ways, transit stops, potable water supply, sanitary waste, parks and recreation, playgrounds, schools and school grounds and safe walking conditions for students who only walk to school; and it will serve the public use and interest. 3. The conditions for final plat approval recommended below are in the public interest and are reasonable and proportionate requirements necessary to mitigate the impacts ofthe development upon the environment. 4. The dedications ofland or easements within and adjacent to the proposed plat, as required for final plat approval or as shown on the proposed preliminary plat submitted by the Applicant on March 17, 2006 and the conceptual recreation plan submitted March 22, 2007 (exh. 26), are reasonable and necessary as a direct result of the development of this proposed plat, and are proportionate to the impacts of the development. 5. No provisions are required to be made by this subdivision for the protection of the red-tail hawks nestCs) on the site. 6. The proposed future development designation for Tract E has been withdrawn by the applicant, and that tract shall be a portion of the designated recreation area for the current development. 7. The proposed conceptual recreation plan submitted as exh. no. 26 is a reasonable and appropriate plan to serve the plats of East Renton and Rosemonte jointly. Minor alterations may be made in the final design and review by DOES, and boundary adjustments, if necessary, may be made to comply with provisions ofKCC 21A. 14. I 80-200. • L02P0005-East Renton 5 8. Revisions to the wetland buffers will be necessary to comply with the provisions of the King County Critical Areas Code, to permit construction of 145th Avenue Southeast in the vicinity of the north property line and to mitigate the impacts of the trail connecting Tracts E and G. 9. In order to provide for safe walking conditions for students walking from this development to Apollo Elementary School, urban improvements must be made to 148th Avenue Southeast north from the proposed plat to the north side of Southeast 117th Street. These improvements should be made to the west side of 148th Avenue Southeast to the extent it is feasible to do so. In the event it is not practical to construct improvements extending to the existing crosswalk located at the north side of Southeast I 17th Street, a crosswalk may be established south of Southeast I I 7th Street and a safe walkway provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast 117th Street. 10. Calculations for surface water detention facilities shall assure that the release of storm water from the site does not exceed the rates allowed by the 1998 King County Drainage Manual for achieving Level 1 flow control. DECISION: The proposed preliminary plat of East Renton, as revised and received on March 17, 2006, is approved, subject to the following conditions of final plat approval: 1. Compliance with all platting provisions of Title 19A of the King County Code. 2. All persons having an ownership interest in the subject property shall sign on the face of the final plat a dedication that includes the language set forth in King County Council Motion No. 5952. 3. The plat shall comply with the base density and minimum density requirements of the R-4 zone classification. All lots shall meet the minimum dimensional requirements of the R-4 zone classification or shall be as shown on the face of the approved preliminary plat, whichever is larger, except that minor revisions to the plat which do not result in substantial changes may be approved at the discretion of the Department of Development and Environment Services. Any/all plat boundary discrepancy(ies) shall be resolved to the satisfaction of DOES prior to the submittal of the final plat documents. As used in this condition, "discrepancy" is a boundary hiatus, an overlapping boundary or a physical appurtenance which indicates an encroachment, lines of possession or a conflict of title. 4. The applicant must obtain final approval from the King County Health Department. 5. All construction and upgrading of public and private roads shall be done in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). (Also see conditions 8 and 24.) --------------------------------------------------------------------------------- L02P0005-Easl Renlon 6. The applicant must obtain the approval of the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the King County Code. 6 All future residences constructed within this subdivision are required to be sprinklered (NFPA 13D) unless the requirement is removed by the King County fire Marshal or hislher designee. The Fire Code requires all portions of the exterior walls of structures to be within 150 feet (as a person would walk via an approved route around the building) from a minimum 20-foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement, driving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. The road width requirement applies to both on-site access and roads accessing the subdivision. 7. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location oflots as shown on the preliminary approved plat. Preliminary review has identified the following conditions of approval, which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual. DDES approval of the drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review shall be shown on the engineering plans. c. The following nole shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DDES and/or the Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designaled for individual lot infiltration systems, the systems shall be constructed at the time of the building permit and shall comply with the plans on file." d. Storm water facilities shall be designed using the KCRTS level one flow control standard. Water quality facilities shall also be provided using the basic waler quality protection menu. The size of the proposed drainage tracts may have 10 increase to accommodate the required detention volumes and water quality facilities. All runoff control facilities shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for recreation space in accordance with KCC 2IA.l4.180. L02P0005-East Renton 7 e. The applicant has received approval for two drainage adjustment applications regarding designs for the discharge of storm water and a shared facility detention pond. The adjustment decisions are contained within file numbers L02V0089 and L04VOI03. During final review of the engineering plans, aH applicable conditions of the adjustment approvals shaH be satisfied including requirements for the shared facility located offsite within the plat of Rosemonte. f. As stated in the drainage adjustment decision, the offsite drainage pond shaH be designed using the Level I flow control standard. Basic water quality standards are also required for design of the facility. If a wet pond facility is provided for water quality, the design shaH comply with the 3:1 flow length ratio as outlined on page 6-72 in the drainage manual. For evaluation of the onsite storm vault and the offsite detention pond, a soils report shaH be prepared by a geotechnical engineer to evaluate the soils and groundwater conditions. g. For any proposed bypass of storm water from the flow control facility, the final drainage designs shaH comply with applicable design requirements in the drainage manual as outlined on pages 1-36 and 3-52. h. As required by Special Requirement No.2 in the drainage manual, the 100-year floodplain boundaries for the onsite wetlands shaH be shown on the final engineering plans and recorded plat. Access and Roads 8. The proposed subdivision shaH comply with the 1993 King County Road Standards (KCRS) including the foHowing requirements: a. During preliminary review the applicant submitted a road variance application (File No. L03V0049), regarding the crest vertical curve and substandard stopping sight distance along the plat frontage. In response to the variance application, the King County Road Engineer provided a decision letter dated October 20, 2004 which approved the variance based upon specific design criteria for constructing 148 th Ave SE. As noted in the variance decision, the crest curve on I 48 th Ave SE must be reconstructed to provide 455 feet of stopping sight distance based upon design criteria with a 2-foot target. The final road improvements and design plans for the project shaH demonstrate compliance with aH applicable conditions of approval as stated in the variance decision. b. 148 th Avenue SE shaH be improved along the frontage as an urban collector arterial including aH design criteria from the road variance decision. In accordance with KCRS 2.02, the curb location shaH be designed at 22-feet from the road crown to provide fuH width travel lanes and a bike lane. The preliminary design plans for East Renton shows road grading extending outside the right-of-way on the east side of 148 th Ave SE. During final engineering review, the applicant shaH acquire easements for any proposed construction on private property or provide an alternative design which is acceptable to King County for road construction within the existing right-of-way. L02P0005-East Renton 8 c. The project entry road to l4Sth Ave SE shall be improved as an urban neighborhood collector. As shown on the preliminary plat, the required right-of-way width is 56 feet. d. The proposed roads within the subdivision shall be improved using urban design standards and in accordance with the street classifications shown on the preliminary plat map. e. Tract D shall be improved as a private joint use driveway serving a maximum of two lots. The lots served shall have undivided ownership of the tract and be responsible for its maintenance. As specified in KCRS 3.0IC, improvements shall include an IS foot paved surface and a minimum tract width of 20 feet. Drainage control shall include a curb or thickened edge on one side. f. Street trees shall be included in the design of all road improvements and shall comply with Section 5.03 of the KCRS. g. Street illumination shall be provided along the plat frontage and at intersections with arterials in accordance with KCRS 5.05. h. The proposed road improvements shall address the requirements for road surfacing outlined in KCRS Chapter 4. As noted in section 4.0IF, full width pavement overlay is required where widening existing asphalt, unless otherwise approved by King County. i. l4Sth Ave SE is classified as an arterial street which may require designs for bus zones and turn outs. As specified in KCRS 2.16, the designer shall contact Metro and the local school district to determine specific requirements. J. Modifications to the above road conditions may be considered by King County pursuant to the variance procedures in KCRS I.OS. 9. All utilities within proposed rights-of-way must be included within a franchise approved by the King County Council prior to final plat recording. 10. The site plans for East Renton show the northerly road stub for 14Sth Ave SE which may extend into the wetland buffer and associated setback within the Rosemont plat. During engineering review for East Renton, a revised road alignment and grading plan shall be provided which demonstrates that road construction within Rosemonte will comply with applicable sensitive area codes. The revised road design and grading plan may result in modification or loss of lots as shown on the preliminary plat. Alternatively, the applicant may seek approval to use buffer averaging as a means to revise the location ofthe buffer and BSLB to achieve code compliance within Rosemonte. II. There shall be no direct vehicular access to or from l4Sth Ave SE from those lots which abut it. A note to this effect shall appear on the engineering plans and the final plat. 12. The applicant shall provide a safe walking access to Apollo Elementary School with urban improvements along the west side of 14Sth Ave NE to the existing crosswalk on the north side of , L02P0005-East Renton 9 SE 117th St. This improvement includes urban frontage improvements along property frontage of the Plat of East Renton, urban improvements along frontage of Rosemonte and urban improvements north to the existing crosswalk on the north side of SE 117th ST. (It is noted that the adjoining plat of Rose monte also will be subject to urban frontage requirements and urban improvements north to the existing crosswalk on the north side of SE I 17 th ST.) In the event it is not practical to construct urban improvements on the west side of 148th Avenue Southeast extending to the existing crosswalk, a new crosswalk may be established south of Southeast I I 7th Street and a safe walkway provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast I 17th Street. This alternative may use a graded surface on the east side of 148th Ave SE to ensure that school-age pedestrians are provided an acceptable-width walkway surface behind the curbing. The walkway shall be designed to the satisfaction of the school district and DDES. Mitigation/Impact Fees 13. The applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either: (1) pay the MPS fee at the final plat recording, or (2) pay the MPS fee at the time of building permit issuance. Ifthe first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All fees required by King County Code 14.75, Mitigation Payment System (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building permit application. 14. Lots within this subdivision are subject to King County Code 2IA.43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shall be assessed and collected immediately prior to the recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shall be allocated evenly to the dwelling units in the plat and shall be collected prior to building permit issuance. Wetlands IS. Preliminary plat review has identified specific requirements which apply to this project as listed below. All other applicable requirements from K.C.C. 21A.24 shall also be addressed by the applicant. a. The Class 2 wetland shall have a minimum 50-foot buffer of undisturbed vegetation as measured from the wetland edge. b. Sensitive area tract(s) shall be used to delineate and protect sensitive areas and buffers in development proposals for subdivisions and shall be recorded on all documents of title of record for all affected lots .. L02P0005-East Renton 10 c. Buffer width averaging may be allowed by King County if it will provide additional protection to the wetland/stream or enhance their functions, as long as the total area contained in the buffer on the development proposal site does not decrease. In no area shall the buffer be less than 65 percent of the required minimum distance. To ensure such functions are enhanced a mitigation plan will be required for the remaining on-site sensitive areas. An enhancement plan shall be submitted for review during engineering review. d. A IS-foot BSBL shall be established from the edge of buffer and/or the sensitive areas Tract(s) and shown on all affected lots. e. To ensure long term protection of the Sensitive Areas a split-railed fence of no more than 4 feet in height shall be installed along the Sensitive Area Tract boundaries in the area of proposed lots. Sensitive Area signs shall be attached to the fence at no less than 100 foot intervals. f. If alterations of streams and/or wetlands are approved in conformance with K.C.C. 21A.24, then a detailed plan to mitigate for impacts from that alteration will be required to be reviewed and approved along with the plat engineering plans. A performance bond or other financial guarantee will be required at the time of plan approval to guarantee that the mitigation measures are installed according to the plan. Once the mitigation work is completed to a DOES Senior Ecologist's satisfaction, the performance bond may be replaced by a maintenance bond for the remainder of the five-year monitoring period to guarantee the success of the mitigation. The applicant shall be responsible for the installation, maintenance and monitoring of any approved mitigation. The mitigation plan must be installed prior to final inspection of the plat. g. Prior to commencing construction activities on the site, the applicant shall temporarily mark sensitive areas tract(s) in a highly visible manner, and these areas must remain so marked until all development proposal activities in the vicinity of the sensitive areas are completed. h. During engineering plan review the applicant shall provide a wetland hydrology analysis to demonstrate how the wetland hydrology will be maintained post-construction. i. Detention out-fall structures maybe permitted within the wetland/stream buffers, however, structures shall be located in the outer edge of the buffer, if possible. All buffer impacts shall be mitigated. 16. Development authorized by this approval may require other state and/or federal permits or approvals. It is the applicant's responsibility to correspond with these agencies prior to beginning work on the site. 17. During engineering review, the plan set shall be routed to the sensitive areas group to determine if the above conditions have been met. , L02P0005-East Renton II Geotechnical . lB. The applicant shall delineate all on-site erosion hazard areas on the final engineering plans (erosion hazard areas are defined in KCC 2IA.06.4IS). The delineation of such areas shall be approved by a DOES geologist. The requirements found in KCC 21A.24.220 concerning erosion hazard areas shaH be met, including seasonal restrictions on clearing and grading activities. Sensitive Area 19. The following note shall be shown on the final engineering plan and recorded plat: Other RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tract/sensitive area and buffer conveys to the public a beneficial interest in the land within the tract/sensitive area and buffer. This interest includes the preservation of native vegetation for aH purposes that benefit the public health, safety and welfare, including control of surface water and erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tract/sensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tract/sensitive area and buffer the obligation, enforceable on behalf of the public by King County, to leave undisturbed all trees and other vegetation within the tract/sensitive area and buffer. The vegetation within the tract/sensitive area and buffer may not be cut, pruned, covered by fill, removed or damaged without approval in writing from the King County Department of Development and Environmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tract/sensitive area and buffer and the area of development activity must be marked or otherwise flagged to the satisfaction of King County prior to any clearing, grading, building construction or other development activity on a lot subject to the sensitive area tract/sensitive area and buffer. The required marking or flagging shaH remain in place until all development proposal activities in the vicinity of the sensitive area are completed. No building foundations are aHowed beyond the required IS-foot building setback line, unless otherwise provided by law. 20. The plat design shall be revised to provide the minimum suitable recreation space consistent with the requirements ofK.C.C. 21A14.1BO and K.C.C. 21A. 14.190 (i.e., minimum area, as well as, sport court[s], children's play equipment, picnic table[s], benches, etc.), as shown on hearing exh. no. 26. a. A detailed recreation space plan (Le., location, area calculations, dimensions, landscape specs, equipment specs, etc.) shaH be submitted for review and approval by DOES prior to or concurrent with the submittal of engineering plats. L02P0005-East Renton b. A perfonnance bond for recreation space improvements shall be posted prior to recording of the plat. 12 21. Tract E shall be designated for recreational area, with an approved trail (across wetland buffers) extending from the recreational Tract G and functioning as an extension of recreation from Tract G. Plans for the tract -designation and design, shall comply with codes and shall be to the satisfaction ofDDES prior to engineering approval. 22. A homeowners' association or other workable organization shall be established to the satisfaction of DDES which provides for the ownership and continued maintenance of the recreation, open space and/or sensitive area tract(s) which combines usage of recreation area within L03POOI8, the plat of Rosemonte, pursuant to hearing exh. no. 26. (See condition no. 25.) 23. Street trees shall be provided as follows (per KCRS 5.03 and K.C.C. 21A.16.050): a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. c. If King County detennines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right-of-way line. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the county has adopted a maintenance program .. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DDES if located within the right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or stonn sewers, or that is not compatible with overhead utility lines. f. The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DDES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at (206) 684-1622 to detennine if 148" Ave SE is on a bus route. If 148" Ave SE is a bus route, the street tree plan shall also be reviewed by Metro. h. The street trees must be installed and inspected, or a perfonnance bond posted prior to recording of the plat. If a perfonnance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the • • L02P0005-East Renton 13 SEPA trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for One year. After one year, the maintenance bond may be released after DOES has completed a second inspection and determined that the trees have been kept healthy and thriving. 1. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on the current county fees. 24. The following have been established by SEPA as necessary requirements to mitigate the adverse environmental impacts of this development. The applicants shall demonstrate compliance with these items prior to final approval. (I.) To mitigate the significant adverse impact the plat of East Renton will have on the intersections of SR 9001148'" Ave SE and SR 9001164'" Ave SE, the applicant shall install, either individually or in conjunction with other development projects in this area, the following improvements at the SR 900/148'" Ave intersection: • A traffic signal, and • Eastbound and westbound left tum lanes The design for the SR 900/148'" Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by King County to the extent such improvements are located in County right-of-way). In addition, at a minimum, the existing entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet, respectively) shall not be reduced as part of the intersection improvements. Documentation shall be submitted to show this requirement is met. All construction work associated with the intersection improvements shall be completed between April 1" and September 30"'. This seasonal restriction shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantee with WSDOT which assures the installation of these improvements within two years of the recording of East Renton. In this event, intersection improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-rata share dollar amount to be paid shall be set by WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip distribution for East Renton L02POOOS-East Renton 14 • The total trips contributed to the intersection of SR 900.14S th Ave by the plats of Aster Park (LOOP0024), Stone Ridge 9L99P300S), East Renton (L02P0005), Shamrock (L02POO 14), Rosemonte (aka Ironwood -L03POO IS), Martin (L05POO 19) and any future land use applications submitted to King County for which compliance with the King County Intersection Standards (KCC 14.S0) is required at either the SR 900/14S tIi Ave intersection, or the SR 900/1 64th Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu ofthe approach described above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years ofthe date of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 21 A.2S.060A] (2.) Documentation shall be provided to demonstrate to the satisfaction ofWSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900114S th Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 14Sth Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 2IA.28.060A] 25. The recreation area may serve the adjacent plat of Rosemonte. If necessary, boundary line adjustments may be approved to establish a portion of the East Renton plat recreation area as a part of the Rosemonte Plat, or the two plats may be recorded as a single plat. 26. Wetland buffer averaging or additional buffer are required to compensate for reduction of wetland buffers adjacent to 145th Avenue southeast, as proposed in the vicinity of the north property line, and to compensate for construction of the recreation tract trail through wetland buffer between Tracts E and G. ORDERED this 5th day of April, 2007. TRANSMITTED this 5th day of April, 2007, to the parties and interested persons of record: Robert L. Anderson PO Box 353 Maple Valley WA 98038 CamWest Devel., Inc. Attn: Sara Slatten 9720 NE 120th PI. # I 00 Kirkland W A 98034 Kristine & Keith Childs 12004 -148th Ave. SE Renton W A 98059 • L02P0005-East Renton 15 Claudia Donnelly Renee & Mark Engbaum John Graves 10415 - 1 47th Ave. SE 5424 NE 10th st. Lozier Homes Renton W A 98059 Renton W A 98059-4386 1203 I 14th Ave. SE Bellevue W A 98004 Ralph Hickman Robert D. Johns Rebecca Lind 9720 NE I 20th PI. #100 Johns Monroe Mitsunaga City of Renton, EDNSP Kirkland W A 98034 1601 - I 14th Ave. SE, # 110 lOSS S. Grady Way Bellevue W A 98004 Renton W A 98057 Seattle KC Health Dept. Triad Associates Kim Claussen E. Dist. Environ. Health 12112 -115th Ave NE DDESILUSD 14350 SE Eastgate Way Kirkland W A 98034 MS OAK-DE-OIOO Bellevue W A 98007 Lisa Dinsmore Peter Dye Nick Gillen DDESILUSD DDESILUSD DDESILUSD MS OAK-DE-OIOO MS OAK-DE-OIOO MS OAK-DE-0100 Shirley Goll Kristen Langley Karen Scharer DDESILUSD DDESILUSD DDESILUSD MS OAK-DE-0100 MS OAK-DE-OIOO MS OAK-DE-0100 Steve Townsend Larry West Kelly Whiting DDESILUSD DDESILUSD KC DOT, Rd. Srvcs. Div. MS OAK-DE-OIOO MS OAK-DE-OIOO MS KSC-TR-023I Bruce Whittaker DDESILUSD MS OAK-DE-0100 NOTICE OF RIGHT TO APPEAL In order to appeal the decision of the Examiner, written notice of appeal must be filed with the Clerk of the King County Council with a fee of $250.00 (check payable to King County Office of Finance) on or before April 19, 2007. Ifa notice of appeal is filed, the original and six (6) copies ofa written appeal statement specifying the basis for the appeal and argument in support of the appeal must be filed with the Clerk ofthe King County Council on or before April 26, 2007. Appeal statements may refer only to facts contained in the hearing record; new facts may not be presented on appeal. Filing requires actual delivery to the Office of the Clerk of the Council, Room 1025, King County Courthouse, 516 3'" Avenue, Seattle, Washington 98104, prior to the close of business (4:30 p.m.) on the date due.' Prior mailing is not sufficient if actual receipt by the Clerk does not occur within the applicable time period. The Examiner does not have authority to extend the time period unless the Office of the Clerk is not open on the specified closing date, in which event delivery prior to the close of business on the next business day is sufficient to meet the filing requirement. L02P0005-East Renton 16 Ifa written notice of appeal and filing fee are not filed within fourteen (14) calendar days of the date of this report, or if a written appeal statement and argument are not filed within twenty-one (21) calendar days of the date of this report, the decision of the hearing examiner contained herein shall be the final decision of King County without the need for further action by the Council. MINUTES OF THE MARCH 22, 2007, PUBLIC HEARING ON DEPARTMENT OF DEVELOPMENT AND ENVIRONMENTAL SERVICES FILE NO. L02P0005 lames N. O'Connor was the Hearing Examiner in this matter. Participating in the hearing were Karen Scharer, Pete Dye and Kristen Langley, representing the Department; Robert lohns representing the Applicant; and Renee Engbaum. Exhibit No. I Exhibit No.2 DDES file L02P0005 DDES preliminary report for L02P0005, prepared 12/29/2006 with attachments as follow: 2.1. Plat Map w/66 Lot Plat Design 2.2. City of Renton Sewer Availability 2.3. Road VarianceIL03V0049 2.4. Surface Water Management VarianceIL02V0089 2.5 Surface Water Management VarianceIL04VOI03 2.6. Density Calculations wlR-4 zoning 2.7 Recreation cross section for Tract G (previously labeled Tract C) Exhibit No.3 Application for land use permit no. AOIP0071 received 4/312002 Exhibit No.4 Environmental checklist received 4/3/2002 Exhibit No.5 Revised SEPA Mitigated Determination of Non significance, date of revised issuance: 12/29/2006 Exhibit No.6 Affidavit of posting of Notice of Application indicating posting date of 5/3/2002, received by DDES on 5/3/2002 Exhibit No.7 Revised Site plan (66 lot preliminary plat map) received 3/17/2006 Exhibit No.8 Assessor's maps (2) SE 10-23-05 & SW 11-23-05 Exhibit No.9 Revised Level I Downstream Analysis by Triad & Associates, received 11124/2004 Exhibit No. 10 Traffic Impact Analysis by Gary Struthers Associates received 4/312002 Exhibit No. II Request for School Information form from the Issaquah School District, received 4/25/2002 Exhibit No. 12 King County Certificate of Water Availability, received 4/03/2002 Exhibit No. 13 Vicinity Map for L05POOl9, L03POOl8 & L02P0005, prepared by KC staff on 3/19/2007 Exhibit No. 14 DDES Field Report and GIS Information dated 511/2002 Exhibit No. 15 Revised Wetlands Determination and Habitat analysis by C. Gary Schulz dated 9112/2002 L02P0005-East Renton 17 Exhibit No. 16 Exhibit No. 17 Exhibit No. 18 Exhibit No. 19 Exhibit No. 20 Exhibit No. 21 Exhibit No. 22 Exhibit No. 23 Exhibit No. 24 Exhibit No. 25 Exhibit No. 26 Exhibit No. 27 Exhibit No. 28 Exhibit No. 29 JNOC:gao L02P0005 RPT Watertype/stream Classification Survey comments from Washington Trout, dated 10/15/2004 Drainage outfall report by Associated Earth Sciences, Inc., dated 9/24/2002 Boundary line adjustment proposal with attached map, dated 5/3/2004 Not entered Response to East Renton Transportation Comments by Gary Struthers Associates, Inc., dated 1123/2003 Washington State Department of Tranportation comments regarding Traffic Impact Analysis, dated 11/13/2002 Letter from Claudia Donnelly dated 6/13/2003 regarding basin plan, with 2 attachments Note from Claudia Donnelly with attached copy of 11112/03 newspaper article regarding transportation model City of Renton comments, regarding sewer service, dated 3/28/2002 Revised language for Condition 6 Conceptual recreation plan by Triad Associates Revised preliminary plat received March 22, 2007 Letter from Renee and Mark Engbaum dated March 22, 2007, with attached map indicating the location of their property Revisions to Conditions 20, 21 and 22 ~~ ----------------------------------- L02P0005 Peter Oye DDES/LUSD MS OAK-DE-0100 REPORT AND DECISION OFFICE OF THE HEARING EXAMINER KING COUNTY, WASIDNGTON 400 Yesler Way, Room 404 Seattle, Washington 98104 Telephone (206) 296-4660 Facsimile (206) 296-1654 Email: hearex@metrokc_gov April 5, 2007 SUBJECT: Department of Development and Environmental Services File No_ L02P0005 Proposed Ordinance no. 2007-0010 EAST RENTON Preliminary Plat Application Location: West of I 48th Avenue Southeast at approximately Southeast 120th Street, Renton Applicant: CamWest Real Estate Dev., Inc. represented by Robert Johns, Attorney Johns Monroe Mitsunaga 1601 -I 14th Ave. SE, # 110 Bellevue, Washington 98004 Telephone: (425) 467-9960 Facsimile: (425) 451-2818 King County: Department of Development and Environmental Services (DDES) represented by Karen Scharer 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 Telephone: (206) 296-7114 Facsimile: (206) 296-7051 SUMMARY OF RECOMMENDA TIONSIDECISION: Department's Preliminary Recommendation: Department's Final Recommendation: Examiner's Decision: EXAMINER PROCEEDINGS: Hearing Opened: Continued for Administrative Purposes: Hearing Closed: Approve subject to conditions . 'Approve subject to conditions (modified) Approve subject to conditions (modified) March 22, 2007 March 22, 2007 March 23, 2007 L02P0005-East Renton 2 The public heating on the proposed subdivision of East Renton was conducted concurrently with the public heating on the proposed subdivision of Rosemonte (DDES File No. L03POO 18). Participants at the public heating and the exhibits offered and entered are listed in the attached minutes. At 12:31 p.m. the heating was continued for administrative purposes, to allow for the submission of proposed exh. no. 29, that would set forth the final recommendation of the department concerning revisions to recommended conditions #'s 6, 20, 21 and 22. Exhibit 29 was received by the Heating Examiner on March 22, 2007, and the heating was declared closed on March 23, 2007 A verbatim recording of the heating is available in the office of the King County Heating Examiner. ISSUES AND TOPICS ADDRESSED: • • Future development tract Red-tailed hawks nest Safe walking conditions SUMMARY: • • • Recreation area Wetland buffers Surface water drainage The proposed subdivision of 17.0 I acres into 66 lots in the urban area is approved subject to conditions. FINDINGS, CONCLUSIONS & DECISION: Having reviewed the record in this matter, the Examiner now makes and enters the following: FINDINGS: I. General Information: Developer: Engineer: STR: Location: Zoning: Acreage: Number of Lots: Density: Lot Size: Camwest Real Estate Development, Inc. 9720 NE 1201h Place, Suite 100 Kirkland, W A 98034 Contact: Sars Slatten 425-825-1955 Ttiad Associates 121l21151h AveNE Kirkland, W A 98034 Contact: Gerry Buck 425-821-8448 10-23-05 West of I 48 1h Ave SE at approximately SE 1201h St. Parcel -1023059023 R-4 17.Dl acres 66 Approximately 3.9 units per acre Approximately 5,000 square feet in size L02P0005-East Renton Proposed Use: Sewage Disposal: Water Supply: Fire District: School District: Single Family Detached Dwellings City of Renton Water District # 90 City of Renton Issaquah School District Complete Application Date: April 17, 2002 3 2. Except as modified herein, the facts set forth in the King County Land Use Services Division's preliminary report to the King County Hearing Examiner for the March 22, 2007, public hearing are found to be correct and are incorporated herein by this reference. The LUSD staff recommends approval of this subdivision, subject to conditions. 3. Development of this subdivision may affect, and lead to the abandonment of, a red-tailed hawks nest on the subject property. The red-trail hawk is not an endangered or threatened species, and no protection of the red-tail hawk is afforded by law or the King County Code within the designated urban area of King County. 4. The applicant has proposed the establishment of Tract E as a "future development" tract. DDES determined that there is no reasonable access available to Tract E that would not cross wetland or wetland buffer. At the hearing the applicant abandoned its request to designate Tract E as a "future development" tract, and proposes to establish that tract as recreation area, to be connected by trail with the designated recreation/detention Tract G within this subdivision and adjacent to the proposed plat of Rosemonte. 5. The applicant has submitted a revised recreation plan for this subdivision and the adjacent plat of Rosemonte (exh. 26). This plan provides adequate area within Tracts C, G and E and within the proposed recreation tract and trail within Rosemonte to serve these plats jointly with well conceived amenities for recreation and open space, consistent with the requirements of the King County Code. To the extent that a portion of the recreation area necessary to meet the requirements for the plat of Rose monte is located on the East Renton property, that can be corrected by boundary line adjustment or recording the two plats as a single plat, ifDDES determines that it is necessary to do so. 6. Wetland buffers within this subdivision will need to be modified, utilizing the buffer averaging provisions of the critical areas code, to accommodate the proposed alignment of 145th Avenue Southeast in the vicinity of the north property line, and adding buffer to mitigate the impacts of the proposed trail corridor within Tract F (between Tracts E and G), in accordance with the provisions ofKCC 2IA.24.045.D.47.b. 7. The proposed subdivision will provide for safe walking conditions for students who will walk to Apollo Elementary School on southeast 1 1 7th Street by constructing urban improvements to 148th Avenue Southeast from the plat to Southeast I 17th Street. A school crosswalk (crossing 148th Avenue Southeast) is located on the north side of Southeast I 1 7th Street, where an existing walkway is used by students to travel along the north side of Southeast I I 7th Street east from 148th Avenue Southeast to the school. This crosswalk also serves students walking from the area north of Southeast II 7th Street. Consequently, the crosswalk should be maintained on the L02P0005-East Renton 4 north side of Southeast I I 7th Street unless it is physically impractical to do so be.cause of constraints resulting from the topography within the right-of-way for 148th Avenue Southeast, south of Southeast II 7th Street. If those constraints preclude extending curb, gutter and sidewalk from the plat of East Renton to the north side of Southeast I I 7th Street, the crosswalk can be relocated to the south, and improvements made on the east side of 148th Avenue Southeast to Southeast I 17th Street. 8. The conceptual review of drainage plans has shown that there are no downstream impacts likely to occur from development of the subject property if Level I flow control and basic water quality treatment improvements are designed and constructed in accordance with the 1998 King County Drainage Manual. The final drainage plan will include calculations to assure that the capacity of drainage facilities and discharge rates will be consistent with those flow control standards. CONCLUSIONS: I. If approved subject to the conditions recommended below, the proposed subdivision wiII comply with the goals and objectives of the King County Comprehensive Plan, subdivision and zoning codes, and other official land use controls and policies of King County. 2. If approved subject to the conditions recommended below, this proposed subdivision will make appropriate provision for the public health, safety and general welfare, and for open spaces, drainage ways, streets, other public ways, transit stops, potable water supply, sanitary waste, parks and recreation, playgrounds, schools and school grounds and safe walking conditions for students who only walk to school; and it will serve the public use and interest. 3. The conditions for final plat approval recommended below are in the public interest and are reasonable and proportionate requirements necessary to mitigate the impacts of the development upon the environment. 4. The dedications of land or easements within and adjacent to the proposed plat, as required for final plat approval or as shown on the proposed preliminary plat submitted by the Applicant on March 17, 2006 and the conceptual recreation plan submitted March 22, 2007 (exh. 26), are reasonable and necessary as a direct result of the development of this proposed plat, and are proportionate to the impacts of the development. 5. No provisions are required to be made by this subdivision for the protection of the red-tail hawks nest(s) on the site. 6. The proposed future development designation for Tract E has been withdrawn by the applicant, and that tract shall be a portion of the designated recreation area for the current development. 7. The proposed conceptual recreation plan submitted as exh. no. 26 is a reasonable and appropriate plan to serve the plats of East Renton and Rosemonte jointly. Minor alterations may be made in the final design and review by DOES, and boundary adjustments, if necessary, may be made to comply with provisions ofKCC 2IA.14.l80-200. L02P0005-East Renton 5 8. Revisions to the wetland buffers will be necessary to comply with the provisions of the King County Critical Areas Code, to permit construction of 145th Avenue Southeast in the vicinity of the north property line and to mitigate the impacts of the trail connecting Tracts E and G. 9. In order to provide for safe walking conditions for students walking from this development to Apo110 Elementary School, urban improveme~ts must be made to 148th Avenue Southeast north from the proposed plat to the north side of Southeast 117th Street. These improvements should be made to the west side of 148th Avenue Southeast to the extent it is feasible to do so. In the event it is not practical to construct improvements extending to the existing crosswalk located at the north side of Southeast 117th Street, a crosswalk may be established south of Southeast 117th Street and a safe walkway provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast 117th Street. 10. Calculations for surface water detention facilities shal1 assure that the release of storm water from the site does not exceed the rates al10wed by the 1998 King County Drainage Manual for achieving Level I flow control. DECISION: The proposed preliminary plat of East Renton, as revised and received on March 17, 2006, is approved, subject to the fol1owing conditions of final plat approval: I. Compliance with al1 platting provisions of Title 19A of the King County Code. 'f. Al1 persons having an ownership interest in the subject property shan sign on the face of the final plat a dedication that includes the language set forth in King County Council Motion No. 5952. 3. The plat shall comply with the base density and minimum density requirements of the R-4 zone classification. All lots shall meet the minimum dimensional requirements of the R-4 zone classification or shall be as shown on the face of the approved preliminary plat, whichever is larger, except that minor revisions to the plat which do not result in substantial changes may be approved at the discretion of the Department of Development and Environment Services. Any/all plat boundary discrepancy(ies) shall be resolved to the satisfaction ofDDES prior to the submittal of the final plat documents. As used in this condition, "discrepancy" is a boundary hiatus, an overlapping boundary or a physical appurtenance which indicates an encroachment, lines of possession or a conflict of title. 4. The applicant must obtain final approval from the King County Health Department. 5. Al1 construction and upgrading of public and private roads shall be done in accordance with the .King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). (Also see conditions 8 and 24.) -------------------------------- L02P0005-East Renton 6. The applicant must obtain the approval of the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the King County Code. 6 All future residences constructed within this subdivision are required to be sprinklered (NFPA 13D) unless the requirement is removed by the King County fire Marshal or hislher designee. The Fire Code requires all portions of the exterior walls of structures to be within 150 feet (as a person would walk via an approved route around the building) from a minimum 20-foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement, driving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. The road width requirement applies to both on-site access and roads accessing the subdivision. 7. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location oflots as shown on the preliminary approved plat. Preliminary review has identified the following conditions of approval, which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual. DDES approval of the drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review shall be shown on the engineering plans. c. The following note shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DDES and/or the Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for individual lot infiltration systems, the systems shaIl be constructed at the time of the building permit and shall comply with the plans on file." d. Storm water facilities shall be designed using the KCRTS level one flow control standard. Water quality facilities shaIl also be provided using the basic water quality protection menu. The size ofthe proposed drainage tracts may have to increase to accommodate the required detention volumes and water quality facilities. All runoff control facilities shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for recreation space in accordance with KCC 2IA.14.l80. '. ~----------------------------------------- L02P0005-E.st Renton 7 e. The applicant has received approval for two drainage adjustment applications regarding designs for the discharge of stonn water and a shared facility detention pond. The adjustment decisions are contained within file numbers L02V0089 and L04VOI03. During final review of the engineering plans, all applicable conditions of the adjustment approvals shall be satisfied including requirements for the shared facility located offsite within the plat of Rose monte. f. As stated in the drainage adjustment decision, the offsite drainage pond shall be designed using the Level I flow control standard. Basic water quality standards are also required for design of the facility. Ifa wet pond facility is provided for water quality, the design shall comply with the 3:1 flow length ratio as outlined on page 6-72 in the drainage manual. For evaluation of the onsite stonn vault and the offsite detention pond, a soils report shall be prepared by a geotechnical engineer to evaluate the soils and groundwater conditions. g. For any proposed bypass of stonn water from the flow control facility, the final drainage designs shall comply with applicable design requirements in the drainage manual as outlined on pages 1-36 and 3-52. h. As required by Special Requirement No.2 in the drainage manual, the 100-year floodplain boundaries for the onsite wetlands shall be shown on the final engineering plans and recorded plat. Access and Roads 8. The proposed subdivision shall comply with the 1993 King County Road Standards (KCRS) including the following requirements: a. During preliminary review the applicant submitted a road variance application (File No. L03V0049), regarding the crest vertical curve and substandard stopping sight distance along the plat frontage. In response to the variance application, the King County Road Engineer provided a decision letter dated October 20, 2004 which approved the variance based upon specific design criteria for constructing 148 1h Ave SE. As noted in the variance decision, the crest curve on 1481h Ave SE must be reconstructed to provide 455 feet of stopping sight distance based upon design criteria with a 2-foot target. The final road improvements and design plans for the project shall demonstrate compliance with all applicable conditions of approval as stated in the variance decision. b. 1481h Avenue SE shall be improved along the frontage as an urban collector arterial including all design criteria from the road variance decision. In accordance with KCRS 2.02, the curb location shall be designed at 22-feet from the road crown to provide full width travel lanes and a bike lane. The prelirrrinary design plans for East Renton shows road grading extending outside the right-of-way on the east side of 148 1h Ave SE. During final engineering review, the applicani shall acquire easements for any proposed construction on private property or provide an alternative design which is acceptable to King County for road construction within the existing right-of-way. L02P0005-East Renton 8 c. The project entry road to 14Sth Ave SE shall be improved as an urban neighborhood collector. As shown on the preliminary plat, the required right-of-way width is 56 feet. d. The proposed roads within the subdivision shall be improved using urban design standards and in accordance with the street classifications shown on the preliminary plat map. e. Tract D shall be improved as a private joint use driveway serving a maximum of two lots. The lots served shall have undivided ownership of the tract and be responsible for its maintenance. As specified in KCRS 3.0IC, improvements shall include an IS foot paved surface and a minimum tract width of 20 feet. Drainage control shall include a curb or thickened edge on one side. f. Street trees shall be included in the design of all road improvements and shall comply with Section 5.03 of the KCRS. g. Street illumination shall be provided along the plat frontage and at intersections with arterials in accordance with KCRS 5.05. h. The proposed road improvements shall address the requirements for road surfacing outlined in KCRS Chapter 4. As noted in section 4.0IF, full width pavement overlay is required where widening existing asphalt, unless otherwise approved by King County. 1. 148 th Ave SE is classified as an arterial street which may require designs for bus zones and turn outs. As specified in KCRS 2.16, the designer shall contact Metro and the local school district to determine specific requirements. J. Modifications to the above road conditions may be considered by King County pursuant to the variance procedures in KCRS I.OS. 9. All utilities within proposed rights-of-way must be included within a franchise approved by the King County Council prior to final plat recording. 10. The site plans for East Renton show the northerly road stub for 145"' Ave SE which may extend into the wetland buffer and associated setback within the Rosemont plat. During engineering review for East Renton, a revised road alignment and grading plan shall be provided which demonstrates that road construction within Rosemonte will comply with applicable sensitive area codes. The revised road design and grading plan may result in modification or loss of lots as shown on the preliminary plat. Alternatively, the applicant may seek approval to use buffer averaging as a means to revise the location of the buffer and BSLB to achieve code compliance within Rosemonte. II. There shall be no direct vehicular access to or from 148"' Ave SE from those lots which abut it. A note to this effect shall appear on the engineering plans and the final plat. 12. The applicant shall provide a safe walking access to Apollo Elementary School with urban improvements along the west side of 148"' Ave NE to the existing crosswalk on the north side of L02P0005-East Renton 9 SE 117'" St. This improvement includes urban frontage improvements along property frontage of the Plat of East Renton, urban improvements along frontage of Rosemonte and urban improvements north to the existing crosswalk on the north side of SE 117'" ST. (It is noted that the adjoining plat of Rosemonte also will be subject to urban frontage requirements and urban improvements north to the existing crosswalk on the north side of SE I 17 th ST.) In the event it is not practical to construct urban improvements on the west side of 148th Avenue Southeast extending to the existing crosswalk, a new crosswalk may be established south of Southeast I 17th Street and a safe walkway provided on the east side of 148th Avenue Southeast from the new crosswalk to the north side of Southeast I I 7th Street. This alternative may use a graded surface on the east side of 148th Ave SE to ensure that school-age pedestrians are provided an acceptable-width walkway surface behind the curbing. The walkway shaIl be designed to the satisfaction of the school district and DDES. Mitigationllmpact Fees 13. The applicant or subsequent owner shaIl comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either: (I) pay the MPS fee at the final plat recording, or (2) pay the MPS fee at the time of building permit issuance. If the first option is chosen, the fee paid shaH be the fee in effect at the time of plat application and a note shaH be placed on the face of the plat that reads, "AH fees required by King County Code 14.75, Mitigation Payment System (MPS), have been paid." If the second option is chosen, the fee paid shaH be the amount in effect as of the date of building permit application. 14. Lots within this subdivision are subject to King County Code 2IA.43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shaIl be assessed and coIlected immediately prior to the recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shaIl be aHocated evenly to the dweHing units iIi the plat and shaH be coHected prior to building permit issuance. Wetlands 15. Preliminary plat review has identified specific requirements which apply to this project as listed below. AH other applicable requirements from K.C.C. 21A.24 shaH also be addressed by the applicant. a. The Class 2 wetland shaH have a minimum 50-foot buffer of undisturbed vegetation as measured from the wetland edge. b. Sensitive area tract(s) shaH be used to delineate and protect sensitive areas and buffers in development proposals for subdivisions and shaH be recorded on aH documents of title of record for all affected lots. L02P0005-East Renton 10 c. Buffer width averaging may be allowed by King County if it will provide additional protection to the wetland/stream or enhance their functions, as long as the total area contained in the buffer on the development proposal site does not decrease. In no area shall the buffer be less than 65 percent of the required minimum distance. To ensure such functions are enhanced a mitigation plan will be required for the remaining on-site sensitive areas. An enhancement plan shall be submitted for review during engineering review. d. A IS-foot BSBL shall be established from the edge of buffer and/or the sensitive areas Tract(s) and shown on all affected lots. e. To ensure long term protection ofthe Sensitive Areas a split-railed fence of no more than 4 feet in height shall be installed along the Sensitive Area Tract boundaries in the area of proposed lots. Sensitive Area signs shall be attached to the fence at no less than 100 foot intervals. f. If alterations of streams and/or wetlands are approved in conformance with K.C.C. 2IA.24, then a detailed plan to mitigate for impacts from that alteration will be required to be reviewed and approved along with the plat engineering plans. A performance bond or other financial guarantee will be required at the time of plan approval to guarantee that the mitigation measures are installed according to the plan. Once the mitigation work is completed to a DOES Senior Ecologist's satisfaction, the performance bond may be replaced by a maintenance bond for the remainder of the five-year monitoring period to guarantee the success of the mitigation. The applicant shall be responsible for the installation, maintenance and monitoring of any approved mitigation. The mitigation plan must be installed prior to final inspection of the plat. g. Prior to commencing construction activities on the site, the applicant shall temporarily mark sensitive areas tract(s) in a highly visible manner, and these areas must remain so marked until all development proposal activities in the vicinity of the sensitive areas are completed. h. During engineering plan review the applicant shall provide a wetland hydrology analysis to demonstrate how the wetland hydrology will be maintained post-construction. 1. Detention out-fall structures maybe permitted within the wetland/stream buffers, however, structures shall be located in the outer edge of the buffer, if possible. All buffer impacts shall be mitigated. 16. Development authorized by this approval may require other state and/or federal permits or approvals. It is the applicant's responsibility to correspond with these agencies prior to beginning work on the site. 17. During engineering review, the plan set shall be routed to the sensitive areas group to determine if the above conditions have been met. ,------------------------ L02P0005-East Renton 11 Geotechnical 18. The applicant shall delineate all on-site erosion hazard areas on the final engineering plans (erosion hazard areas are defined in KCC 21A.06.415). The delineation of such areas shall be approved by a DOES geologist. The requirements found in KCC 2IA.24.220 concerning erosion hazard areas shall be met, including seasonal restrictions on clearing and grading activities. Sensitive Area 19. The following note shall be shown on the final engineering plan and recorded plat: Other RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tract/sensitive area and buffer conveys to the public a beneficial interest in the land within the tract/sensitive area and buffer. This interest includes the preservation of native vegetation for all purposes that benefit the public health, safety and welfare, including control of surface water and erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tract/sensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tract/sensitive area and buffer the obligation, enforceable on behalf of the public by King County, to leave undisturbed all trees and other vegetation within the tract/sensitive area and buffer. The vegetation within the tract/sensitive area and buffer may not be cut, pruned, covered by fill, removed or damaged without approval in writing from the King County Department of Development and Environmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tract/sensitive area and buffer and the area of development activity must be marked or otherwise flagged to the satisfaction of King County prior to any clearing, grading, building construction or other development activity on a lot subject to the sensitive area tract/sensitive area and buffer. The required ~arking or flagging shall remain in place until all development proposal activities in the vicinity of the sensitive area are completed. No building foundations are allowed beyond the required IS-foot building setback line, unless otherwise provided by law. 20. The plat design shall be revised to provide the minimum suitable recreation space consistent with the requirements ofK.C.C. 21A.14.180 and K.C.C. 21A. 14.190 (i.e., minimum area, as well as, sport court[s], children's play equipment, picnic table[s], benches, etc.), as shown on hearing exh. no. 26. a. A detailed recreation space plan (i.e., location, area calculations, dimensions, landscape specs, equipment specs, etc.) shall be submitted for review and approval by DOES prior to or concurrent with the submittal of engineering plats. L02P0005-East Renton b. A performance bond for recreation space improvements shall be posted prior to recording of the plat. 12 21. Tract E shall be designated for recreational area, with an approved trail (across wetland buffers) extending from the recreational Tract G and functioning as an extension of recreation from Tract G. Plans for the tract -designation and design, shall comply with codes and shall be to the satisfaction of DOES prior to engineering approval. 22. A homeowners' association or other workable organization shall be established to the satisfaction of DOES which provides for the ownership and continued maintenance of the recreation, open space and/or sensitive area tract(s) which combines usage of recreation area within L03P0018, the plat of Rosemonte, pursuant to hearing exh. no. 26. (See condition no. 25.) 23. Street trees shall be provided as follows (per KCRS 5.03 and K.C.C. 2lA.16.050): a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. c. If King County determines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right-of-way line. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the county has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DOES iflocated within the right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or storm sewers, or that is not compatible with overhead utility lines. f. The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DOES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at (206) 684-1622 to determine if 148 1h Ave SE is on a bus route. If 148 th Ave SE is a bus route, the street tree plan shall also be reviewed by Metro. h. The street trees must be installed and inspected, or a performance bond posted prior to recording of the plat. If a performance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the L02P0005-Easl Renton 13 SEPA trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year. After one year, the maintenance bond may be released after DDES has completed a second inspection and determined that the trees have been kept healthy and thriving. 1. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on the current county fees. 24. The following have been established by SEPA as necessary requirements to mitigate the adverse environmental impacts of this development. The applicants shall demonstrate compliance with these items prior to final approval. (I.) To mitigate the significant adverse impact the plat of East Renton will have on the intersections ofSR 900/148"' Ave SE and SR 900/164"' Ave SE, the applicant shall install, either individually or in conjunction with other development projects in this area, the following improvements at the SR 900/148"' Ave intersection: • A traffic signal, and • Eastbound and westbound left turn lanes The design for the SR 9001148"' Ave intersection improvements shall be approved by the Washington State Department of Transportation (and by King County to the extenrsuch improvements are located in County right-of-way). In addition, at a minimum, the existing entering sight distance looking east for the north and south legs of the intersection (602 feet and 386 feet, respectively) shall not be reduced as part of the intersection improvements. Documentation shall be submitted to show this requirement is met. All construction work associated with the intersection improvements shall be completed between April 1" and September 30"'. This seasonal restriction shall be clearly shown on the final engineering plans. In lieu of the installation of the above-noted intersection improvements prior to final plat approval, the applicant may post a financial guarantee with WSDOT which assures the installation of these improvements within two years of the recording of East Renton. In this event, intersection improvement design must be approved by WSDOT prior to King County approval of the engineering plans for East Renton. If the above-noted intersection improvements have already been made by others prior to the recording of East Renton, or a financial guarantee has been posted by others which assures the installation of these improvements, then the applicant for East Renton shall pay a pro-rata share dollar amount to the developer who has made the improvements or "bonded" for the improvements, in an amount proportional to the impacts of East Renton. The pro-rata share dollar amount to be paid shall be set by WSDOT, and documentation shall be provided by the East Renton applicant to the King County Land Use Services Division to show this payment has been made, prior to final plat recording. The pro-rata dollar amount to be paid shall be based on the following: • The final East Renton lot count • The trip distribution for East Renton L02P0005-East Renton 14 • The total trips contributed to the intersection ofSR 900.14S th Ave by the plats of Aster Park (L00P0024), Stone Ridge 9L99P300S), East Renton (L02P0005), Shamrock (L02POO 14), Rosemonte (aka Ironwood -L03POO IS), Martin (L05POO 19) and any future land use applications submitted to King County for which compliance with the King County Intersection Standards (KCC 14.S0) is required at either the SR 900/14S tIi Ave intersection, or the SR 9001164 th Ave High Accident Location. In the event that either King County or WSDOT adopts a formal "latecomer's" system prior to final plat recording, that system may be followed in lieu of the approach described above, at the discretion of the applicant, as long as at a minimum there is a financial guarantee which assures the above-noted intersection improvements will be installed within two years ofthe date of recording of the plat of East Renton. [Comprehensive Plan Policy T-303 and King County Code 2IA.2S.060A) (2.) Documentation shall be provided to demonstrate to the satisfaction ofWSDOT that stopping sight distance (360 feet) is available on the east leg of the SR 900114S th Ave intersection. The intersection shall be modified by the applicant, if necessary, so that this stopping sight distance requirement is met on the east leg. In addition, the applicant shall clear vegetation within the right-of-way along SR 900, east of 148 th Ave., to maximize the entering sight distance for the north and south legs of the intersection. [Comprehensive Plan Policy T-303 and King County Comprehensive Policy T-303 and King County Code 21A.28.060A] 25. The recreation area may serve the adjacent plat of Rosemonte. If necessary, boundary line adjustrhents may be approved to establish a portion of the East Renton plat recreation area as a part of the Rosemonte Plat, or the two plats may be recorded as a single plat. 26. Wetland buffer averaging or additional buffer are required to compensate for reduction of wetland buffers adjacent to 145th Avenue southeast, as proposed in the vicinity of the north property line, and to compensate for construction of the recreation tract trail through wetland buffer between Tracts E and G. ORDERED this 5th day of April, 2007. . O'Connor C unty Hearing Examiner pro tern TRANSMITTED this 5th day of April, 2007, to the parties and interested persons of record: Robert L. Anderson POBox 353 Maple Valley W A 98038 CamWest Devel., Inc. Attn: Sara Slatten 9720 NE I 20th PI. #100 Kirkland W A 98034 Kristine & Keith Childs 12004 -14Sth Ave. SE Renton W A 9S059 ,------------------------------------------------------I L02P0005-East Renton 15 Claudia Donnelly Renee & Mark Engbaum John Graves 10415 -147th Ave. SE 5424 NE 10th St. Lozier Homes Renton W A 98059 Renton W A 98059-4386 1203 I 14th Ave. SE Bellevue W A 98004 Ralph Hickman Robert D. Johns Rebecca Lind 9720 NE I 20th PI. #100 Johns Monroe Mitsunaga City of Renton, EDNSP Kirkland W A 98034 1601 - I 14th Ave. SE, # 110 1055 S. Grady Way Bellevue W A 98004 Renton W A 98057 Seattle KC Health Dept. Triad Associates Kim Claussen E. Dist. Environ. Health 12112 -115th Ave NE DDESILUSD 14350 SE Eastgate Way Kirkland W A 98034 MS OAK-DE-OIOO Bellevue W A 98007 Lisa Dinsmore Peter Dye Nick Gillen DDESILUSD DDESILUSD DDESILUSD MS OAK-DE-OIOO MS OAK-DE-OIOO MS OAK-DE-OIOO Shirley Goll Kristen Langley Karen Scharer DDESILUSD DDESILUSD DDESILUSD MS OAK-DE-OIOO MS OAK-DE-OIOO MS OAK-DE-OIOO Steve Townsend Larry West Kelly Whiting DDESILUSD DDESILUSD KC DOT, Rd. Srvcs. Div. MS OAK-DE-OIOO MS OAK-DE-OIOO MS KSC-TR-023I Bruce Whittaker DDESILUSD MS OAK-DE-OIOO NOTICE OF RIGHT TO APPEAL In order to appeal the decision of the Examiner, written notice of appeal must be filed with the Clerk of the King County Council with a fee of $250.00 (check payable to King County Office of Finance) on or before April 19, 2007. Ifa notice of appeal is filed, the original and six (6) copies ofa written appeal statement specifying the basis for the appeal and argument in support of the appeal must be filed with the Clerk of the King County Council on or before April 26, 2007. Appeal statements may refer only to facts contained in the hearing record; new facts may not be presented on appeal. Filing requires actual delivery to the Office ofthe Clerk of the Council, Room 1025, King County Courthouse, 516 3'" Avenue, Seattle, Washington 98104, prior to the close of business (4:30 p.m.) on the date due. Prior mailing is not sufficient if actual receipt by the Clerk does not occur within the applicable time period. The Examiner does not have authority to extend the time period unless the Office of the Clerk is not open on the specified closing date, in which event delivery prior to the close of business on the next business day is sufficient to meet the filing requirement. L02P0005-East Renton 16 If a written notice of appeal and filing fee are not filed within fourteen (14) calendar days of the date of this report, or if a written appeal statement and argument are not filed within twenty-one (21) calendar days of the date of this report, the decision of the hearing examiner contained herein shall be the final decision of King County without the need for further action by the Council. MINUTES OF THE MARCH 22, 2007, PUBLIC HEARING ON DEPARTMENT OF DEVELOPMENT AND ENVIRONMENTAL SERVICES FILE NO. L02P0005 James N. O'Connor was the Hearing Examiner in this matter. Participating in the hearing were Karen Scharer, Pete Dye and Kristen Langley, representing the Department; Robert Johns representing the Applicant; and Renee Engbaum. Exhibit No. I Exhibit No.2 Exhibit No.3 Exhibit No.4 Exhibit No. S Exhibit No.6 Exhibit No.7 Exhibit No.8 Exhibit No.9 Exhibit No. \0 Exhibit No. II Exhibit No. 12 Exhibit No. 13 Exhibit No. 14 Exhibit No. IS DDES file L02POOOS DDES preliminary report for L02POOOS, prepared 12129/2006 with attachments as follow: 2.1. Plat Map w/66 Lot Plat Design 2.2. City of Renton Sewer Availability 2.3. Road VarianceIL03V0049 2.4. Surface Water Management VarianceIL02V0089 2.5 Surface Water Management VarianceIL04VOI03 2.6. Density Calculations wlR-4 zoning 2.7 Recreation cross section for Tract G (previously labeled Tract C) Application for land use pennit no. AOIP0071 received 4/3/2002 Environmental checklist received 4/3/2002 Revised SEPA Mitigated Detennination of Non significance, date of revised issuance: 12/29/2006 Affidavit of posting of Notice of Application indicating posting date of S13/2002, received by DDES on SI3/2002 Revised Site plan (66 lot preliminary plat map) received 3/17/2006 Assessor's maps (2) SE 10-23-0S & SW 11-23-0S Revised Level I Downstream Analysis by Triad & Associates, received 11124/2004 Traffic Impact Analysis by Gary Struthers Associates received 4/312002 Request for School Infonnation fonn from the Issaquah School District, received 4/2S/2002 King County Certificate of Water Availability, received 4/03/2002 Vicinity Map for LOSPOOI9, L03POOl8 & L02POOOS, prepared by KC staff on 3/19/2007 DDES Field Report and GIS Infonnation dated S/l/2002 Revised Wetlands Detennination and Habitat analysis by C. Gary Schulz dated 9/12/2002 L02P0005-East Renton Exhibit No. 16 Watertype/stream Classification Survey comments from Washington Trout, dated 10115/2004 Exhibit No. 17 Drainage outfall report by Associated Earth Sciences, Inc., dated 9/24/2002 Exhibit No. 18 Boundary line adjustment proposal with attached map, dated 5/3/2004 Exhibit No. 19 Not entered 17 Exhibit No. 20 Response to East Renton Transportation Comments by Gary Struthers Associates, Inc., dated 1123/2003 Exhibit No. 21 Washington State Department of Tranportation comments regarding Traffic Impact Analysis, dated 11/\3/2002 Exhibit No. 22 Letter from Claudia Donnelly dated 6/13/2003 regarding basin plan, with 2 attachments Exhibit No. 23 Note from Claudia Donnelly with attached copy of 11112/03 newspaper article regarding transportation model Exhibit No. 24 City of Renton comments, regarding sewer service, dated 3/28/2002 Exhibit No. 25 Revised language for Condition 6 Exhibit No. 26 Conceptual recreation plan by Triad Associates Exhibit No. 27 Revised preliminary plat received March 22, 2007 Exhibit No. 28 Letter from Renee and Mark Engbaum dated March 22, 2007, with attached map indicating the location of their property Exhibit No. 29 Revisions to Conditions 20, 21 and 22 JNOC:gao L02P0005 RPT Denis Law· ,,::--.... _~~!~~.--------~ _'::"Mayor ......... ..--,.~1IDID Decerriber 7, 2.01.5 Erin Hopkins " TolI,Brothers , 972QN E 12Q'h PI, Suite 2.0.0, Kirkland, WA 98034· -,.," < ".,' ""--, .' ", • ' • .' Community & Economic Development Department, , , ' C.E,"Chip"Vincent, Administrator SUBJECT: Receipt of 2nd Annual Wetland Maintenance and Monitoring Report ' Claremont (aka East Renton, Rosemont) Residential Plat Mitigation Project ", City of Renton File LUAQ9-lO.o, . , Dear Erin Hopkins: I received the second annual Maintenance and MOl1it~'ring 'Report for'the Claremont, Residential Plat Mitigation Projectprepared by Selival,1 Wetland Consulting, dated November 24; 2.015. In review of the report, the project appears to be meeting general "performance standards' and is considered,in compli~nce: Jhereport states that no' specific goals were listed on the plan. I gathered t~e approved mitigation'and " performance standards from theprojecffile and ani providing them tovol. as an' 'attachment; , , Please refer to the,approved mitigation and performan~e standardsfdr the next report if they are'differentJrom the general plan goals listed in the submitted report. , In addition, please,takethe necessary measures as recommended by your wetland' biologist to secure the survival of the plantings and limit the non-native plant coverages. Three'print copies ahdanelectronic copy (PDF) of your next scheduled, maintenance,and, , ' ' monitoring report are due to the city by November 2.0, 2.016; If you have, any questions, please contact meat (42S) 43.0-6593. Sincerely, ~t~U.4'''''''' Kris Sorensen, Associate Planner Planning Division cc: Ed Sewall, Sewall Wetland Consulting / Wetland Ecologist City of Renton File lUA09~100 Attach: Mitigation Plan and Performance Standards Renton City Hall • 1055 South Grady Way • Renton, Washington 98057 • rentonwa.gov / ,/ /' ' r .' _.-'-re '. Mitigation Standards/Monitoring ProgramiMaintenance F6f! CC~OW'lEftJJ This wetland buffer mitigation section is provided as a supplement to the East RentonIRosemonte Wetland Buffer Mitigation Plan (Sheets WLI ~ WL3, Triad Associates 8-11- OS).·The supplement includes the typical components of a final mitigation plan including maintenance and monitoring programs. The intent oflhe Plan is to facilitate reasonable development of the East Renton/Rosemonte project and also improve and restore wetland buffer conditions. In addition to planting native plant species, non-native invasive plants will be removed. As part of the allowed wetland buffer averaging, thePlan targets an increase in wetland buffer functions with restoration and enhancement plantings. MITIGATION GOALS • Enhance and improve existiog wetland buffer functions by adding species diversity and structure with new trees and shrubs. • Remove invasive & non-native species in enhanced wetland buffer areas. • Restore temponary impacts to the wetland buffer with native vegetation. • Preserve & maintain areas of enhanced & restored wetland buffer. PERFORMANCE STANDARDS • Provide enhancement of at least 34,776 square feet of wetland buffer area within Tract F. • Restore all disturbed areas in the wetland buffer related to project construction activities. • Establish at least 6 native tree species and 12 native shrub species in the buffer. • Provide 80 percent survival of all installed trees and shrubs by the end of the 5 years of monitoring. • Maintain less than 10 percent non-native, invasive plant cover in planted areas by the end of the 5 years of monitoring. PERFORMANCE SECURITY Per the City's sensitive areas code, a performance security or other instrument is required to guarantee mitigation success. Generally, the costs that are associated with installation, maintenance, and monitoring are used for performance security. Actual costs may vary depending on several factors, including; I) source of plant material, 2) site preparation work, 3) contract landscaper, and 4) consultant hired for monitoring. An estimated cost or use of contract bids for mitigation enhancement work may be used to determine a performance security. ~----"'/O!tI"'tc!f'1fft&'/fiMlJllie ~may provide a bond worksheet calculation method to determine security. P1annin -',lvJ.tC@Ilil a J,1\ /i'5lff1l 9 DIVISion trfJ[j=~fPd®JW7I By ::£[J//l (A -./" ~ fQ) Date~~ The Project Ecologist's role is to oversee implementation of the Plan and to insure that all specifications are met. The Project Ecologist will observe site preparation and planting phases. Construction oversight will be provided for the removal of invasive, non-native plants and the protection of existing vegetation to remain. COMPLIANCE MONITORING The landscape contractor will notify the Project Ecologist and project proponent when planting has been completed. At that time, the ecologist will review tbe Plan and completed mitigation areas to assess compliance. Locations of installed trees and shrubs tbat differ from the approved planting plan will be noted or mapped. A report of compliance, including any deficiencies ,,!,d resolutions, will be prepared for the City. Assuming installation occurs in 2013, the first compliance-monitoring event would occur late in 2013 or early in 2014 to verify complete plan implementation. Subsequent monitoring, reporting, and maintenance will follow the Monitoring Program during the 5 years following installation. Landscape contractor is responsible for plant installation and maintenance during the first full year after the approved installation. MONITORING PROGRAM An ecologist (qualified wetland/stream professional) will monitor the mitigation areas for at least 3 years following installation. Observations of the wetland buffer enhancement plantings will be made early in tbe growing season (5/1 to 5/30) and end of the growing season (9/1 to 9/30) for the first two years and annually during the last three yearsofthe five-year monitoring period. At the beginning of the growing season during the month of May, monitoring will include a maintenance review as follows: • Identify significant cover of weed, by species, and schedule appropriate maintenance or removal in order to promote the growth and survival of all installed plants. At the end of the growing season during the month of September, monitoring will be as follows: • Count all installed trees and shrubs in the mitigation area for mortality/survival. • Assess the health of all installed trees and shrubs in the mitigation area for any potential disease, infestation, or animal damage. • Identify weed growth, by species and percent cover, and if maintenance is necessary for plant survival. . • Photograph the restored/enhanced buffer area from at least four locations. The location and direction of each photograph shall be consistent among monitoring periods, be representative of restored and enhanced areas, and be represented on a map (Le., properly located and labeled). Submit the results of annual monitoting to the City within 30 days following field monitoting. ., -; fi i' " i' I ~ " " n li " j! :! POR OF THE HE 1/4 OF THE SE 1/4 & THE SE 1/4 OF THE HE 1/4, All IN SEC. to. TWP. 23 N .. RGE. 5 E., W.M. '. d "~d::l~ . <~;.~.;-.-;-- /: S£IJ7pfSf ) .. 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'l 1-~ 'jq ""11><""",",,,' J' ...... ~~f?1j'jJC-'.11'}: APPROVED 12i17i20131iimrmn:; WfTZAND BUFFER CALCULA TlON r=Jb ........ ............, """'" Ii1Milll 1="'1 D ~~~- Zi!:,"':i,;;::u'~"'TL""'- ToT",,--.. ~ U!TLMC>_ -, SHEET INDEX MJ WE7lANOBUFFERMfT1GA.nONPlAN HIll WF11AND BUFFER ENfII1NCEMENT PfANTlNG 1l'PIG1L WlJ BUFFER INHANCEMENT PLANTING NOTES & DETAILS I @ """"P' SCo\lE: 1'" 60' Li....T i 0" '- /LRJAP. ,~,', ... -... ---~ :::i--::_ """iji. ~ ~ ~ ~ g ~ ~ ~ ~ ~ ~ ~ ~ ~ • ~ ~ /!:! ~ ~ :c: • 0 ~ ~ -CI) ~O • ~It: ~, ~ ~:c: ~Q ..... .:c: ULu It: .... CI) ~ -.' ~~ ,,~T' ... ,~~~,a:Cf- --- • e ~ • ~ · ;; -="'''N!D .. 0',047 WLI .. 3 , 1 r-· -.~ "-. ~ "-~~\ ! Hi I . 31.NOIIV350lJ / N01.N3lJ 1.5'<13 I ~ I!; , ' 'I ... ., ~~~ II " . e!li' ilil .:. ... " i , I ~~II J.N3Wd073A30 .LS3MW\f.::t I . iii • • 71fOIdA.l ~NllNlf7d lN3W3:JNVHN3 H3:i:in8 ON'I"l3M -_I •• I ihhl I I I, I " I ill !I! . 1'1 d !' iii , !ll !l ! II III . ,; ! • 1 1 ! .J , , , , • l! j! j! j! !! l! • • , • • w ~ j j , 1 u " .. ~ H~ ~" , = z g , , , , , , , , • M • I ~ ! , >- g l I I .; ! , ! ' i !. , w j , i ! II il !I II Ii II Ii II II II II 0 i ! i I • i ! ,I Ii " I Ii i " ~ l ~I < I I ~ II ! I' I ; i L ~@i w j8®@©2l CD@<Ol@@EB@Q z w ~ + S z >- • 0 ~ W 0 W Z >- ~ ~ W 0 W Z >- • 0 ~ W Z w II z >-• 0 = II 0 • ! ! ! • lilll ~ 11:1; ~ Iii!! .- S1flf.J.3Q 'i S3JON !JNJ.LNlIld I II I Jli " " mil 1:!11 ~ '" !!ill ~ • lIih II !II!!I ~ ~ • ~ filii ~ .: " Il!!il ~ . ~ Il:!l !! ! 1:, ~ • ~ I • 0 ~ a: • ., . ~ , . i 0 u ~ I ~ ~ ~ i ~ ~ ~ e ~ ~ , , , \ ' , , I I j !: I j I , ., , 1 i j 1 j i ~i November 24, 2015 Erin Hopkins Toll Brothers • 9720 NE 120thPlace Kirkland, Washington 98034 Re: Claremont -Year 2-Monitoring Report SWC Job# 13-173 City of Renton File LUAO-9-100 Dear Erin, • Sewall Wetland Consulting, Inc. POBox 880 Phone: 2.53-8.'1).(l;] 5 Fall Oty, W A !:m24 This report describes the results of Sewall Wetland Consulting, Inc. Year 2 monitoring of the Claremont mitigation project, in the City of Renton, Washington. , , 1\' Vicinity Map , .-~.".=! l • , I ,I I , i , I I 1 . 1 .J I ' 1 !. 1 ~ , I i . 1 • ------------------ • Toll Claremontl#13-173 Sewall Wetland Consulting, Inc. November 24, 2015 Page 2 of6 The site located on the west side of Nile Avenue NE (I 48th Avenue SE) in the City of Renton, Washington (the "site"). 1.0 WETLAND MITIGATION CONCEPT AND GOALS I.I Mitigation Concept The project included 9761 sf of buffer reductions and II ,888sf of buffer addition through averaging. As part of this, 34, 776sf of the previously degraded buffer area was enhanced through the removal of Himalayan blackberry and the installation of a mix of native trees and shrubs, The approved plan was prepared by Triad Associates, and was entitled "Cam West Development -East RentoniRosemonte Wetland and Buffer Mitigation Plan". 1.2 Mitigation Goals No specific goals were listed on the plan. As a result we are using the standard goals for an enhancement plan of 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. We are also assuming no more than 10% cover of invasive species in the enhancement area, 2.0 INTRODUCTION Although the success and final outcome of wetland mitigation, restoration and enhancement projects is never guaranteed, certain procedures can be utilized to increase the probability of success. One of the most important procedures for success following proper design and installation is the establishment of a monitoring plan to track changes and developments within the systerll. Monitoring provides the opportunity to evaluate the success of planted material within the system and observe early establishment of pioneer and volunteer species. By observing the success of planted and volunteer species during the first five years of the project, it may be possible to speculate on the successional pathway taken, and general success of the project. Monitoring at the Claremont mitigation area is to be conducted eight times over a five year period. Monitoring was conducted four times the first year, and after Year 1, once a year for the following four years. This report represents the Year report with fieldwork conducted on October of 20 IS. During each site visit the overall success and rigor of the installation plantings is to be evaluated. Observations will also be made for any exotic/invasive species or native volunteer vegetation which may have entered the area . ! I I I I , II • 3.0 STANDARDS OF SUCCESS • Toll Claremont!#13-173 Sewall Wetland Consulting, Inc. November 24. 2015 Page 3 0/6 3.1.1 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. 3.1.2 No more than 10% cover of invasive species in the enhancement area. 4.0 SAMPLING METHODOLOGY All individual plantings will be inspected for health/survival. Visual estimates of invasive coverage will be made. 5.0 OBSERVATIONS AND DISCUSSION OF SITE CONDITIONS The following is our observations of the mitigation site taken in October of2014. 5.1 YEAR 2 MON1TORlNG RESULTS 5.1.1 Survival Statistics for Installed Plant Material A total of IS dead plants of the total of 532 plants installed were found to be dead which equates to a 97% survival rate. As required by the Year 2 criteria, the survival rate for all planted species is 80% at this time and the site is meeting this goal. Herbaceous ground cover remains at approximately 70%. 5.1.2 Invasive vegetation Ongoing blackberry maintenance has continued throughout the year. The north end of the site continues to have blackberry sprouts emerging as a result of the large seed bank that exist in this soil. This covers now about 8% and is comprised of emerging blackberry sprouts. These should be cut and sprayed in the spring to continue the suppression of this weedy species. This meets the criteria required of not more than 10% weedy species coverage. Blackberry control will be performed again in the spring of 2016 to insure this stays below the 10% threshold into the next monitoring period. 6.0 RECOMMENDATIONS & CONCLUSIONS The site is meeting all of the monitoring requirements for Year 2. The next monitoring of the site will be in the late spring of 20 16 to observe weedy species levels and maintenance needs. The full monitoring of the site will occur in September of2016 to --1 I , , I I 1 , j .! ,I • • Toll Claremont!#13-173 Sewall Wetland Consulting, Inc. November 24,2015 Page 4 0/6 count plant survival while plants still retain leaves, A Year 3 report will be prepared and issued by the end of November 2016, If you have any questions or need any additional information please contact me at (253) 859-0515 or by email atesewall@sewallwc.com. Sincerely, Sewall Wetland Consulting, Inc, Ed Sewall Senior Wetland Ecologist PWS #212 • • Toll Clar emonll#13-1 73 Sewall Wetland Consu lting, Inc. November 24 , 2015 Page 5 0/6 11-18-15 photographs of the mitigation area , ' • • Toll Claremon rl#13-1 73 Sewall Wetland Cons liiting , In c. Nove mb er 24, 2015 Page 6 0/6 Denis Law Mayor March 9, 2015 Aaron Kopet Camwest • 9720 NE 120th Place, Suite 100 Kirkland, WA 98034 Community & Economic Development Department C.E."Chip"Vincent, Administrator Subject: Receipt of Quarterly Monitori.ng Reports East Renton/Rosemont Final Plat File No. LUA09-100 (L02POOOS) Dear Mr. Kopet: I received and reviewed the first through fourth Quarterly Performance Monitoring Reports for the East Renton/Rosemont Final Plat mitigation project. This report fulfills your obligation for quarterly monitoring for the first year; you are now required to monitor on a yearly basis for a minimum of four more years. The area must be successfully monitored and maintained for a minimum of five years to assure the success of the wetland mitigation project. Please take the necessary measures as recommended by your wetland biologist to secure the survival of the plantings. Of particular note are the recommendations to reduce competition for the mitigation plantings through maintenance to keep the invasive cover low .. As a reminder, if at any time in the next four years the.mitigation project does not meet the established performance standards, the monitoring period will be put on hold until compliance is achieved. Subsequently, the monitoring timeframe will be restarted and you will once again be required to provide quarterly reports for the first year and annual reports thereafter (for a minimum of five years). If you have any questions, please feel free to contact me. I look forward to receiving your first annual report maintenance and monitoring report on November 4,2015. Sincerely, ?:t:Y~ Senior Planner cc: File LUA09-100, PP, ECF Renton City Hall • 1055 South Grady Way • Renton, Washington 98057 • rentonwa.gov • Sewall Wetland Consulting, Inc. October 21, 2013 Aaron Kopet Cam West -A Toll Bothers Company 9720 NE I 20 th Place Suite 100 Kirkland, Washington 98034 276'11 Covington Way SE #2 Covington W A 'ffi42 RE: Claremont Phase II (East Renton) -Mitigation Installation sign-off SWC Job#13-173 Dear Aaron, Phore:~15 Fax: 25:h'l524732 This letter is to inform you that we have inspected the final plantings on Claremont Phase II (East Renton) buffer mitigation site on October 15,2013. The mitigation project has been installed per the approved East Renton/Rosemont Wetland Buffer Mitigation Plan prepared by Triad Associates. This letter initiates the 5 year monitoring plan. The first years 1st quarter monitoring will take place in January of 20 14, with a report to the City of Renton to follow. If you have any questions regarding this report, please call us at (253) 859-0515 or at esewall@sewallwc.com . Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetlands Ecologist PWS #212 • Sewall Wetland Consulting, Inc. August 2, 2014 Matt Seidel Toll Brothers 9720 NE 120thPIace Kirkland, Washington 98034 fOBox880 FallGty, WA <ro24 Re: Claremont -Year \-3rd Quarterly Report SWC Job#13-173 City of Renton File LUAO-9-100 Dear Matt, Phone: 253-W-C615 RECEIVED MAR -2 2015 CITY OF RENTON PlANNING DIVISION This report describes the results of Sewall Wetland Consulting, Inc. third quarter monitoring of the Claremont mitigation project, in the City of Renton, Washington. Vicinity Map • • Toll Claremontl#13-173 Sewall Wetland Consulting, Inc. August 2,2014 Page 2 oJ4 The site located on the west side of Nile Avenue NE (I 48th Avenue SE) in the City of Renton, Washington (the "site"). 1.0 WETLAND MITIGATION CONCEPT AND GOALS 1.1 Mitigation Concept The project included 9761 sf of buffer reductions and II ,888sf of buffer addition through averaging. As part of this, 34,776sf of the previously degraded buffer area was enhanced through the removal of Himalayan blackberry and the installation of a mix of native trees and shrubs. The approved plan was prepared by Triad Associates, and was entitled "Cam West Development -East RentoniRosemonte Wetland and Buffer Mitigation Plan". 1.2 Mitigation Goals No specific goals were listed on the plan. As a result we are using the standard goals for an enhancement plan of 100% survival of the installed plantings in Year 1, and 80% survival of the installed plantings at the end of the 5 Year monitoring. We are also assuming no more than 10% cover of invasive species in the enhancement area. 2.0 INTRODUCTION Although the success and final outcome of wetland mitigation, restoration and enhancement projects is never guaranteed, certain procedures can be utilized to increase the probability of success. One of the most important procedures for success following proper design and installation is the establishment of a monitoring plan to track changes and developments within the system. Monitoring provides the opportunity to evaluate the success of planted material within the system and observe early establishment of pioneer and volunteer species. By observing the success of planted and volunteer species during the first five years of the project, it may be possible to speculate on the successional pathway taken, and general success of the project. Monitoring at the Claremont mitigation area is to be conducted eight times over a five year period. Monitoring will be conducted four times the first year, and once a year for the following four years. This report represents the third quarter report for Year 1 with fieldwork conducted on July 23 of2014. • • Toll Claremontl#13-173 Sewall Wetland Consl/lting, Inc. Al/gl/st2,2014 Page 3 of4 During each site visit the overall success and rigor of the installation plantings is to be evaluated. Observations will also be made for any exotic/invasive species or native volunteer vegetation which may have entered the area. 3.0 ST ANDARDS OF SUCCESS 3.1.1 100% survival of the installed plantings in Year I. and 80% survival of the installed plantings at the end of the 5 Year monitoring. 3.1.2 No more than 10% cover of invasive species in the enhancement area. 4.0 SAMPLING METHODOLOGY All individual plantings will be inspected for health/survival. Visual estimates of invasive coverage will be made. 5.0 OBSERVATIONS AND DISCUSSION OF SITE CONDITIONS The following is our observations of the mitigation site taken in July of 20 14. 5.1 THIRD QUARTER 5.1.1 Survival Statistics for Installed Plant Material As required by the Year I criteria, the survival rate for all planted species is 100% at this time. Herbaceous ground cover is approximately 70% . 5. I .2 Invasi ve vegetation The enhanced buffer area was originally covered with blackberry. As a result, control of blackberry on this site requires ongoing maintenance and control. Blackberry maintenance has been ongoing since the installation, and currently blackberry coverage (as well as all other weedy species) is just below 10%. This meets the criteria required of not more than 10% weedy species coverage. Blackberry control will be performed again in August to insure this stays below the 10% threshold. • 6.0 RECOMMENDATIONS & CONCLUSIONS • Toll Claremontl#J3-173 Sewall Wetland Consulting, Inc. August 2,2014 Page 4 0/4 The site is meeting all of the monitoring requirements for the 3'd quarter of Year I. If you have any questions or need any additional information please contact me at (253) 859-0515 or by email atesewall@sewallwc.com. Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetland Ecologist PWS #212 • Sewall Wetland Consulting, Inc. May 5, 2014 Matt Seidel Toll Brothers 9720 NE l20thPIace Kirkland, Washington 98034 FDfux880 FaIl GIy, WA ~4 Re: Claremont -Year 1-2nd Quarterly Report SWC Job#13-173 City of Renton File LUAO-9-l 00 Dear Matt, Phone:~5 RECEIVED MAR - 2 70''i CITY OF RENTON PlANNING DIVISION This report describes the results of Sewall Wetland Consulting, Inc, second quarter monitoring of the Claremont mitigation project, in the City of Renton, Washington. Vicinity Map • • Toll Claremont/# 13-173 Sewall Wetland Consulting. Inc. May 5.2014 Page 2 of4 The site located on the west side of Nile Avenue NE (I 48th Avenue SE) in the City of Renton, Washington (the "site"). 1.0 WETLAND MITIGATION CONCEPT AND GOALS 1.1 Mitigation Concept The project included 9761 sf of buffer reductions and II ,888sf of buffer addition through averaging. As part of this, 34,776sf of the previously degraded buffer area was enhanced through the removal of Himalayan blackberry and the installation of a mix of native trees and shrubs. The approved plan was prepared by Triad Associates, and was entitled "Cam West Development -East RentoniRosemonte Wetland and Buffer Mitigation Plan". 1.2 Mitigation Goals No specific goals were listed on the plan. As a result we are using the standard goals for an enhancement plan of 100% survival of the installed plantings in Year 1, and 80% survival of the installed plantings at the end of the 5 Year monitoring. We are also assuming no more than 10% cover of invasive species in the enhancement area. 2.0 INTRODUCTION Although the success and final outcome of wetland mitigation, restoration and enhancement projects is never guaranteed, certain procedures can be utilized to increase the probability of success. One of the most important procedures for success following proper design and installation is the establishment of a monitoring plan to track changes and developments within the system. Monitoring provides the opportunity to evaluate the success of planted material within the system and observe early establishment of pioneer and volunteer species. By observing the success of planted and volunteer species during the first five years of the project, it may be possible to speculate on the succ.essional pathway taken, and general success of the project. Monitoring at the Claremont mitigation area is to be conducted eight times over a five year period. Monitoring will be conducted four times the first year, and once a year for the following four years. This report represents the second quarter report for Year I with fieldwork conducted on April 21 of2014. • • Toll Claremonl/#J 3-173 Sewall Weiland Consulting, Inc. MayS,20J4 Page 3 0/4 During each site visit the overall success and rigor of the installation plantings is to be evaluated, Observations will also be made for any exotic/invasive species or native volunteer vegetation which may have entered the area. 3.0 STANDARDS OF SUCCESS 3.1.1 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. 3.1.2 No more than 10% cover of invasive species in the enhancement area. 4.0 SAMPLING METHODOLOGY All individual plantings will be inspected for health/survival. Visual estimates of invasive coverage will be made. 5.0 OBSERVATIONS AND DISCUSSION OF SITE CONDITIONS The following is our observations of the mitigation site taken in April of2014. 5.1 SECOND QUARTER 5.1.1 Survival Statistics for Installed Plant Material As required by the Year I criteria, the survival rate for all planted species is 100% at this time. Herbaceous ground cover is approximately 50% . 5.1.2 Invasive vegetation The enhanced buffer area was originally covered with blackberry. As a result, control of blackberry on this site requires ongoing maintenance and control. Blackberry maintenance has been ongoing since the installation, and currently blackberry coverage (as well as all other weedy species) is approximately 5% with only a few small scattered blackberry shoots present. This meets the criteria required of not more than 10% weedy species coverage. Blackberry control will be performed again in July to insure this stays below the 10% threshold. • 6_0 RECOMMENDATIONS & CONCLUSIONS • Toll Claremont!#13-173 Sewall Wetland Consulting, Inc. May 5,2014 Page 4 of4 The site is meeting all of the monitoring requirements for the 2nd quarter of Year I. If you have any questions or need any additional information please contact me at (253) 859-0515 or by email atesewall@sewallwc.com. Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetland Ecologist PWS #212 • Sewall Wetland Consulting. Inc. February 7, 2014 Matt Seidel Toll Brothers 9720 NE 120thPlace Kirkland, Washington 98034 fDBax880 Fall Oty, W A 'ID14 Re: Claremont -Year 1-I st Quarterly Report SWC Job#13-173 City of Renton File LUAO-9-100 Dear Matt, Phone: 253-S59-{B15 RECEIVED MAR - 2 20\5 CITY OF RENTON PLANNING DIVISION This report describes the results of Sewall Wetland Consulting, Inc. first quarter monitoring of the Claremont mitigation project, in the City of Renton, Washington. Vicinity Map ---------------------- • • Toll Claremontl#13-l73 Sewall Wetland Consulting, Inc. February 7, 2014 Page 2 oJ7 The site located on the west side of Nile Avenue NE (148th Avenue SE) in the City of Renton, Washington (the "site"). 1.0 WETLAND MITIGATION CONCEPT AND GOALS 1.1 Mitigation Concept The project included 9761 sf of buffer reductions and II ,888sfof buffer addition through averaging. As part of this, 34,776sfofthe previously degraded buffer area was enhanced through the removal of Himalayan blackberry and the installation of a mix of native trees and shrubs. The approved plan was prepared by Triad Associates, and was entitled "Cam West Development -East RentonlRosemonle Wetland and Buffer Mitigation Plan". 1.2 Mitigation Goals No specific goals were listed on the plan. As a result we are using the standard goals for an enhancement plan of 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. We are also assuming no more than 10% cover of invasive species in the enhancement area. 2.0 INTRODUCTION Although the success and final outcome of wetland mitigation, restoration and enhancement projects is never guaranteed, certain procedures can be utilized to increase the probability of success. One of the most important procedures for success following proper design and installation is the establishment of a monitoring plan to track changes and developments within the system. Monitoring provides the opportunity to evaluate the success of planted material within the system and observe early establishment of pioneer and volunteer species. By observing the success of planted and volunteer species during the first five years of the project, it may be possible to speculate on the successional pathway taken, and general success of the project. Monitoring at the Claremont mitigation area is to be conducted eight times over a five year period. Monitoring will be conducted four times the first year, and once a year for the following four years. This report represents the first quarter report for Year I with fieldwork conducted on January 17 of 20 14. • • Toll C/aremont/#J3-173 Sewall Wetland Consulting. Inc. February 7, 20/4 Page 3 of7 During each site visit the overall success and rigor of the installation plantings is to be evaluated. Observations will also be made for any exotic/invasive species or native volunteer vegetation which may have entered the area, 3.0 STANDARDS OF SUCCESS 3.1.1 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. 3.1.2 No more than 10% cover of invasive species in the enhancement area. 4.0 SAMPLING METHODOLOGY All individual plantings will be inspected for health/survival. Visual estimates of invasive coverage will be made. 5.0 OBSERVATIONS AND DISCUSSION OF SITE CONDITIONS The following is our observations of the mitigation site taken in January of 20 14. 5.1 FIRST QUARTER 5.1.1 .Survival Statistics for Installed Plant Material As required by the Year I criteria, the survival rate for all planted species is 100% at this time. Herbaceous ground cover is approximately 50% . 5.1.2 Invasive vegetation The enhanced buffer area was originally covered with blackberry. As a result, control of blackberry on this site will need to be closely monitored. Blackberry maintenance has been ongoing since the installation, and currently blackberry coverage (as well as all other weedy species) is essentially 0% with only a few small scattered blackberry shoots present. This meets the criteria required of not more than 10% weedy species coverage. Blackberry control will be performed again in April to insure this stays below the 10% threshold. • 6.0 RECOMMENDATIONS & CONCLUSIONS • Toll Claremont/# 13-173 Sewall Wetland Consulting, Inc. February 7, 2014 Page 4 of7 The site is meeting all of the monitoring requirements for the I st quarter of Year I. If you have any questions or need any additional information please contact me at (253) 859-0515 or by email atesewall@sewallwc.com. Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetland Ecologist PWS #212 • • Toll Claremon/!# 13-1 73 Sewall Wetland Consll lling, Inc. Febrllary 7, 20 14 Page 5 of7 • • Toll Claremont/# 13-1 73 Sewa ll Weiland Co nsli lling. Inc. Febrllary 7. 2014 Page 6 0/7 • • To ll C1a remon tl#13-173 Sewall Wetland Consulting, In c. February 7,20 14 Page 70f7 .. _----------- • Sewall Wetland Consulting, Inc. November 20, 2014 Matt Seidel Toll Brothers 9720 NE 120thPIace Kirkland, Washington 98034 fDBox&lO Fall Gty, WA ~4 Re: Claremont -Year 1-4th Quarterly Report SWC Job# 13-173 City of Renton File LUAO-9-100 Dear Matt, Phone:~5 RECEIVED MAR -22015 CITY OF RENTON PLANNING DIVISION This report describes the results of Sewall Wetland Consulting, Inc. fourth quarter monitoring of the Claremont mitigation project, in the City of Renton, Washington. Vicinity Map • • Toll Claremont!#13-173 Sewall Wetland Consulting, Inc. November 20,2014 Page 2 oJ6 The site located on the west side of Nile Avenue NE (148th Avenue SE) in the City of Renton, Washington (the "site"). 1.0 WETLAND MITIGATION CONCEPT AND GOALS 1.1 Mitigation Concept The project included 9761 sf of buffer reductions and II ,888sf of buffer addition through averaging. As part of this, 34,776sfofthe previously degraded buffer area was enhanced through the removal of Himalayan blackberry and the installation of a mix of native trees and shrubs. The approved plan was prepared by Triad Associates, and was entitled "Cam West Development -East RentonlRosemonte Wetland and Buffer Mitigation Plan". 1.2 Mitigation Goals No specific goals were listed on the plan. As a result we are using the standard goals for an enhancement plan of 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. We are also assuming no more than 10% cover of invasive species in the enhancement area. 2.0 INTRODUCTION Although the success and final outcome of wetland mitigation, restoration and enhancement projects is never guaranteed, certain procedures can be utilized to increase the probability of success. One of the most important procedures for success following proper design and installation is the establishment of a monitoring plan to track changes and developments within the system. Monitoring provides the opportunity to evaluate the success of planted material within the system and observe early establishment of pioneer and volunteer species. By observing the success of planted and volunteer species during the first five years of the project, it may be possible to speculate on the successional pathway taken, and general success of the project. Monitoring at the Claremont mitigation area is to be conducted eight times over a five year period. Monitoring will be conducted four times the first year, and once a year for the following four years. This report represents the fourth quarter report for Year I with fieldwork conducted on October 13 of2014. During each site visit the overall success and rigor of the installation plantings is to be evaluated. Observations will also be made for any exotic/invasive species or native volunteer vegetation which may have entered the area. • 3.0 STANDARDS OF SUCCESS • Toll Claremontl#13-173 Sewall Wetland Consulting, Inc. November 20, 2014 Page 3 oJ6 3.1.1 100% survival of the installed plantings in Year I, and 80% survival of the installed plantings at the end of the 5 Year monitoring. 3.1.2 No more than 10% cover of invasive species in the enhancement area. 4.0 SAMPLING METHODOLOGY All individual plantings will be inspected for health/survival. Visual estimates of invasive coverage will be made. 5.0 OBSERVATIONS AND DISCUSSION OF SITE CONDITIONS The following is our observations of the mitigation site taken in October of20l4. 5.1 FOURTH QUARTER 5.1.1 Survival Statistics for Installed Plant Material As required by the Year 1 criteria, the survival rate for all planted species is 100% at this time. Herbaceous ground cover remains at approximately 70% . 5.1.2 Invasive vegetation Ongoing blackberry maintenance has continued throughout the year and was performed just prior to our October 13, 2014 site visit. As a result, weedy coverage has been reduced to close to 0%. This meets the criteria required of not more than 10% weedy species coverage. Blackberry control will be performed again in the spring of2015 to insure this stays below the 10% threshold into the next monitoring period. 6.0 RECOMMENDATIONS & CONCLUSIONS The site is meeting all of the monitoring requirements for the fourth quarter of Year I .. The next monitoring of the site will be in the late spring of2015 to observe weedy species levels and maintenance needs. The full monitoring of the site will occur in September of2015 to count plant survival while plants still retain leaves. A Year 2 report will be prepared and issued by the end of November 2015. • • Toll Claremonl/# 13-173 Sewall WeIland Consulting, Inc. November 20,2014 Page 4 0/6 If you have any questions or need any additional information please contact me at (253) 859-0515 or by email atesewall@sewallwc.com. Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetland Ecologist PWS #212 • • Toll Claremon t/#J3-17 3 Se wall Weiland Co nsulting, In c. No vember 20, 2014 Page 5 0/6 • • Toll C1aremon ll#13-1 73 Sewall Wetland Conslllting , Inc . November 20,2014 Page 6 0[6