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HomeMy WebLinkAboutERC_Report_Exhibits_Cherie_Lane_180423DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Project Location Map ERC Report_Cherie Lane_180419 ENVIRONMENTAL REVIEW COMMITTEE REPORT ERC MEETING DATE: April 23, 2018 PART ONE: PROJECT BACKGROUND Project Name: Cherie Lane Short Plat Project Number: PR17-000016 Land Use Permit Number: LUA16-000964, ECF, SHPL-A Project Manager: Jill Ding, Senior Planner Owner/Applicant: Newfourth, LLC, 19244 39th Ave S, SeaTac, WA 98188 Contact: Tom Redding, Encompass Engineering & Surveying, 165 NE Juniper St, Suite 201, Issaquah, WA 98027 Project Location: 34XX Talbot Road S (Parcel No. 3023059108) Project Summary: The applicant is requesting Administrative Short Plat approval, Environmental (SEPA) Review, and Modification approval for the subdivision of an existing 114,798 square foot (2.64 acre) vacant lot zoned R-8 into 2 lots and 1 tract for the construction of new single family residences. Proposed Lot 1 would have an area of 10,665 square feet, Lot 2 would have an area of 40,190 square feet and Tract A, a Native Growth Protection Area, would have an area of 63,951 square feet. Access to Lot 1 would be provided via driveway access off of S 34th Place and access to Lot 2 would be provided via driveway access off of Talbot Road S. High and moderate coal mine hazard areas, a 30,445 square foot Category 4 wetland with a standard 50-foot buffer, and sensitive slopes have been identified on the project site. Exist. Bldg. Area SF: N/A Proposed New Bldg. Area: N/A Site Area: 114,806 SF (2.64 ac) STAFF RECOMMENDATION: Staff Recommends that the Environmental Review Committee issue a Determination of Non-Significance (DNS). City of Renton Department of Community & Economic Development Environmental Review Committee Report CHERIE LANE SHORT PLAT LUA16-000964, ECF, SHPL-A Report of April 23, 2018 Page 2 of 4 ERC Report_Cherie Lane_180419 PART TWO: ENVIRONMENTAL REVIEW In compliance with RCW 43.21C.240, the following environmental (SEPA) review addresses only those project impacts that are not adequately addressed under existing development standards and environmental regulations. A. Environmental Threshold Recommendation Based on analysis of probable impacts from the proposal, staff recommends that the Responsible Officials: Issue a DNS with a 14-day Appeal Period. B. Mitigation Measures 1. None recommended. C. Exhibits Exhibit 1 Environmental Review Committee Report Exhibit 2 Preliminary Shot Plat Map Exhibit 3 Wetland Delineation Report, prepared by Altman Oliver Associates, LLC, dated November 30, 2016 Exhibit 4 Otak Memo dated May 12, 2017 Exhibit 5 Revised Wetland Delineation and Classification report, prepared by Altman Oliver Associates, LLC, dated December 14, 2017 Exhibit 6 Advisory Notes to Applicant Exhibit 7 Coal Mine Hazard Assessment, prepared by Icicle Creek Engineers, Inc., dated December 27, 2016 D. Environmental Impacts The Proposal was circulated and reviewed by various City Departments and Divisions to determine whether the applicant has adequately identified and addressed environmental impacts anticipated to occur in conjunction with the proposed development. Staff reviewers have identified that the proposal is likely to have the following probable impacts: 1. Earth: Impacts: Coal mine hazard areas are mapped on the project site. The applicant submitted a Coal Mine Hazard Assessment, prepared by Icicle Creek Engineers, Inc., dated December 27, 2016 (Exhibit 7) that evaluated and rated the onsite coal mine hazard areas and provided recommendations for development on and around the coal mine hazard areas. The report identified four abandoned underground coal mines underneath the project site. All the mines were developed by opening a “slope” down the coal seam that served as the main haulageway for coal to the surface. From the main haulageway, “chutes” (or tunnels) were driven up the coal seam toward the ground surface. These chutes were then connected by a series of “cross-cuts” (tunnels that connect the chutes). This type of mining is referred to as “room-and-pillar” mining. Upon retreat from the mine, the support pillars of coal between the chutes and cross-cuts were removed (called “pillar-robbing”) to maximize the removal of coal from the mine. The effect of pillar-robbing City of Renton Department of Community & Economic Development Environmental Review Committee Report CHERIE LANE SHORT PLAT LUA16-000964, ECF, SHPL-A Report of April 23, 2018 Page 3 of 4 ERC Report_Cherie Lane_180419 was to dramatically destabilize the mined-out area, therefore, natural collapse (“room caving”) of the mine usually occurred within a few weeks or years. Subsurface conditions of the project site were explored by drilling 19, three-inch diameter borings (B-1 through B-19) to depths ranging from 35 to 95 feet below ground surface. Three high coal mine hazard areas have been identified within proposed Lot 2. No development is recommended over these high coal mine hazard areas, unless the area is “bridged” (structurally spanned) or additional subsurface exploration is completed in order to develop alternative mitigation, as the risk of sink hole occurrence in these areas is high. Moderate coal mine hazard areas have been identified on the central portion of proposed Lot 2 traversing the site from northwest to southeast. In these areas, the risk of sinkhole occurrence is low to moderate. Roads, driveways, outbuildings (sheds), yard and passive use should be allowed in the moderate coal mine hazard areas. Low coal mine hazard areas have been identified on the southwest corner of proposed Lot 2. The development of structures, with mitigation, may be allowed in the low coal mine hazard areas. Recommended mitigation for development in low coal mine hazard areas includes: Small, square or nearly square-shaped building pads should be favored over large, irregularly-shaped building pads; use of rigid foundations (conventional reinforced-concrete spread footings) supporting a flexible superstructure (wood-frame), foundations should extend across the inside of the building footprint rather than using individual column footings; crawl-space construction rather than slab-on-grade (slab-on-grade may be used in garage areas); no brick or basement construction; underground utilities should be designed with flexible and/or telescopic couplings or fittings; ICE should be contacted immediately should house distortion or a ground surface sag/sinkhole be observed; and prospective owners that may occupy structures within Lower Risk High Coal Mine Hazard areas should be made aware that an abandoned underground coal mine exists at a depth of 50+ feet although subsurface exploration suggests that the abandoned mine working have filled with coal and rock fragments or have otherwise collapsed. Staff will be recommending that compliance with the geotechnical report be a condition of preliminary short plat approval. It is anticipated that compliance with the City’s critical areas regulations and building codes will adequately mitigation for impacts to the construction of structures on this site; therefore no further mitigation is recommended at this time. Mitigation Measure: None recommended. Nexus: Not Applicable. 2. Water a. Wetland Impacts: The applicant submitted a Wetland Delineation Report, prepared by Altman Oliver Associates, LLC, dated November 30, 2016 (Exhibit 3) with the project application. The submitted wetland report identified one onsite wetland (Wetland A) and one off-site wetland to the southeast of the project site (Wetland B). The wetland report concluded that Wetlands A and B met the criteria for Category IV wetlands requiring a standard 50-foot buffer. Secondary review of the submitted wetland report was conducted by Otak in a memo dated May 12, 2017 (Exhibit 4). The City of Renton Department of Community & Economic Development Environmental Review Committee Report CHERIE LANE SHORT PLAT LUA16-000964, ECF, SHPL-A Report of April 23, 2018 Page 4 of 4 ERC Report_Cherie Lane_180419 Otak memo identified an off-site wetland to the north, which likely had a buffer that overlapped with the buffer of Wetland A and also identified a seep along the north project boundary that drained into the ditch along Talbot Road S. The report also concluded that Wetlands A and B should be rated as Category III wetlands with 75-foot buffers. Based on the results of the secondary review, the applicant requested an onsite meeting with Otak and the City, the meeting was held on July 10, 2017, as a result of the onsite meeting Otak changed one of their recommendations regarding the classification of Wetland A and concurred with the applicant that Wetland A should be categorized as a Category IV wetland with a 50-foot standard buffer. As a result of the meeting, the applicant submitted a revised Wetland Delineation and Classification report, prepared by Altman Oliver Associates, LLC, dated December 14, 2017 (Exhibit 5). The revised report identified an off-site wetland to the northeast and concluded that this wetland met the criteria for a Category IV wetland with a standard 50-foot buffer, Wetland A remained categorized as a Category IV wetland with a standard 50-foot buffer, the categorization of Wetland B was revised to a Category III wetland with a standard 75-foot buffer, and the onsite seep along the north property boundary was determined to be an artificial surface water drainage that would not be regulated as a critical area by the City. The project proposal is not proposing any impacts to the on or offsite wetlands or buffer areas. Any impacts to the wetland or buffer areas would be adequately mitigated by the City’s adopted Critical Areas Regulations; therefore no further mitigation is recommended. Mitigation Measure: None recommended. Nexus: Not Applicable. E. Comments of Reviewing Departments The proposal has been circulated to City Department and Division Reviewers. Where applicable, their comments have been incorporated into the text of this report and/or “Advisory Notes to Applicant.”  Copies of all Review Comments are contained in the Official File and may be attached to this report. The Environmental Determination decision will become final if the decision is not appealed within the 14-day appeal period (RCW 43.21.C.075(3); WAC 197-11-680). Environmental Determination Appeal Process: Appeals of the environmental determination must be filed in writing together with the required fee to: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98057, on or before 5:00 p.m. on May 11, 2018. RMC 4-8-110 governs appeals to the Hearing Examiner and additional information regarding the appeal process may be obtained from the City Clerk’s Office, Renton City Hall – 7th Floor, (425) 430-6510. November 30, 2016 AOA-1773 Steve Beck Newfourth LLC 19244 39th Ave. S. SeaTac, WA 98188-5316 SUBJECT: Wetland Delineation for Cherie Lane Parcel 302305-9108, Renton, WA Dear Steve: On January 20, 2016 I conducted a wetland delineation on the western portion of the undeveloped subject property utilizing the methodology outlined in the May 2010 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0). Additional field investigations were conducted on September 14 and November 1, 2016. 1.0 EXISTING WETLANDS One wetland (Wetland A) was identified as a mosaic throughout the central portion of the property. The wetland boundary was subsequently surveyed and is depicted on Figure 1. A second wetland (Wetland B) is located off-site to the southeast. The approximate location of this wetland was taken from a map prepared by the Jay Group in 2010 (Attachment A) and the approximate location confirmed during the November 1, 2016 field review. 1.1 Wetland A Mosaic Vegetation within the wetland mosaic includes hydrophytic trees such as black cottonwood (Populus trichocarpa), Pacific willow (Salix lasiandra), and Oregon ash (Fraxinus latifolia). Understory vegetation was dominated by a mix of hydrophytic and mesic species including dense Himalayan blackberry (Rubus armeniacus), snowberry (Symphoricarpos albus), black twinberry (Lonicera involucrata), and sword fern (Polystichum munitum). Soils throughout the wetland generally consisted of a low chroma clay loam mixed with charcoal. Soil profiles were highly variable and have likely been disturbed by historic mining activities. Hydrology within the wetland consists of a seasonal high Technical Memorandum 11241Willows Road NE Suite 200 Redmond, WA 98052 Phone (425) 822-4446 Fax (425) 827-9577 Otak, Inc. (Otak) conducted a review of the wetland delineation report and mitigation plan dated November 30, 2016 and prepared by Altmann Oliver Associates (AOA), LLC, for the proposed preliminary short plat of Parcel #3023059108 in the City of Renton (City). The project applicant is proposing a 5-lot short plat with access from a new road (Cherie Lane), and proposed wetland and wetland buffer enhancement for impacts to wetland buffers. The City requested Otak to complete a secondary review of the delineation report and mitigation plan per Renton Municipal Code (RMC) Chapter 4-3-050 (Critical Areas Regulations), and conduct a site visit to verify the wetland delineation and classifications. Following the review of the submitted materials, a site visit was completed on April 27, 2017. The following materials were submitted by the project proponent and reviewed by Otak:  Wetland Delineation for Cherie Lane, prepared by Altmann Oliver Associates, LLC (dated November 30, 2016)  Preliminary Cherie Lane Site Plan, prepared by Encompass Engineering & Surveying (dated December 21, 2016) The following resources were also reviewed:  Critical Areas Report for Parcel 3023059022, prepared by Sewall Wetland Consulting, Inc. (dated October 20, 2016).  King County iMap (http://gismaps.kingcounty.gov/iMap/), accessed May 1, 2017. To: Jill Ding, Senior Planner Community and Economic Development City of Renton From: Jeff Gray, Senior Wetland Biologist Stephanie Modjeski, Wetland Biologist Copies: File Date: May 12, 2017 Subject: Wetland Delineation and Classification Review Proposed Preliminary Short Plat of Parcel: #3023059108 Project No.: 32847 Jill Ding, Senior Planner, City of Renton Page 2 Cherie Lane– Wetland Delineation and Classification Review May 12, 2017 2  Google Earth Pro, accessed May 1, 2017.  King County Public Health sewage plans search system (http://www.kingcounty.gov/depts/health/environmental-health/piping/onsite-sewage- systems/records/as-built-drawings.aspx), accessed May 1, 2017. Wetland Boundary Delineation, Wetland Classifications, and Buffer Widths Review The wetland boundary delineation onsite is consistent with the 1987 Corps Wetland Delineation Manual and the 2010 Western Mountains, Valleys, and Coast Regional Supplement as required by RMC 4-3-050(G)9-b, but it does not appear adequate for the proposed short plat as not all wetland boundaries were delineated on site. It is unclear if offsite flags AA1 to AA3 are intended to delineate a separate wetland, or if these flags represent a continuation of the boundaries of Wetland A. Flag AA3 is approximately 100 feet away from flag A5, which is the last flag hung for Wetland A. Flags AA1 to AA3 delineate the northwestern edge of a groundwater seep emanating from the coal mine hazard area, and appeared to be a separate wetland. If Wetland flags AA1 to AA3 are intended to delineate a separate wetland, then that wetland also needs to be rated and classified, and the rating form included with the report. If Wetland flags AA1 to AA3 are a continuation of Wetland A, then the applicant needs to delineate the connection in the field as it may affect the proposed buffer averaging plan. The applicant should provide additional wetland data forms to substantiate any revisions to wetland boundaries. Surface water was observed emanating from a seep along the northern property boundary and flowing into the roadside ditch along Talbot Road South (see Figure 1). Wetland vegetation was also present. The applicant should document the presence or absence of wetlands at this location, and provide wetland data forms. The offsite wetland on Parcel #3023059022 north of the proposed short plat likely has a 40 to 50- foot buffer depending on the proposed land use intensity. The buffer from this offsite wetland overlaps with the existing Wetland A buffer onsite. The northern boundary of offsite Wetland B portrayed on Figure 1 of the AOA report appears generally accurate. No flags were observed in the field from the delineation by the Jay Group in 2010. But it is reasonable to suspect that the boundary flagged in 2010 and shown on Figure 1 has not changed due to the abrupt topographic break and distinct wetland/upland boundary observed in the field. Jill Ding, Senior Planner, City of Renton Page 3 Cherie Lane– Wetland Delineation and Classification Review May 12, 2017 3 Figure 1. Groundwater seep area with wetland vegetation shown in the blue circle. On- and off-site wetlands have been rated using the Washington State Wetland Rating System for Western Washington (2014 Update) as required by RMC 4-3-050(G)9-c. Wetland A and Wetland B are rated as Category IV wetlands in the report by AOA, but it is our opinion that these wetlands should be rated as Category III with a 75-foot buffer. The comments listed below pertain to the questions in the rating form. Wetland A  D1.1: No intermittently flowing stream or highly constricted permanently flowing outlet was observed. Wetland A appeared to be a depression with no surface water outlet. Question D1.1 should be 3 points unless the seep at flags AA-1 to AA-3 is found to be part of the Wetland. However, the adjustment of the score from 2 to 3 points for this question does not change the rating for this function.  D2.3: Septic systems occur on parcel number 3023059071 within 250 feet of Wetland A. Although Question D2.3 should be revised from 0 to 1 point, the rating remains the same.  D4.1: No intermittently flowing stream or highly constricted permanently flowing outlet was observed in the field or described in the AOA report. Wetland A appeared to be a depression or flat depression with no surface water outlet. Question D4.1 should be revised to 4 points. The adjustment of the score from 2 to 4 points changes the rating from low to medium, and gives the wetland a score of 5 for overall hydrologic functions. Jill Ding, Senior Planner, City of Renton Page 4 Cherie Lane– Wetland Delineation and Classification Review May 12, 2017 4  H3.1: Snags and downed logs that meet the definition of WDFW listed priority habitats were observed within 100 meters of Wetland A. Question H3.1 should be 1 point. An increase from 0 to 1 point changes the rating from low to medium, and gives the wetland a rating of 4 for overall habitat functions. Adjustments to hydrologic and habitat ratings changes the overall score of Wetland A to 16, resulting in Wetland A being classified as Category III. Category III wetlands with a habitat score of 4 require a buffer of 75 feet with a 15-foot structure setback for other than low impact land uses per RMC 4-3-050(G)2. The wetland rating forms and buffers should be revised accordingly. Wetland B  H3.1: Snags and downed logs that meet the definition of WDFW listed priority habitats were observed within 100 meters of Wetland B. Question H3.1 should be 1 point. An increase from 0 to 1 point changes the rating from low to medium, and gives the wetland a rating of 4 for overall habitat functions. Adjustments to the habitat rating changes the overall score of Wetland B to 17, resulting in Wetland B being classified as Category III. Category III wetlands with a habitat score of 4 for all land use require a buffer of 75 feet with a 15-foot structure setback for other than low impact land uses per RMC 4-3-050(G)2. The wetland rating forms and buffers should be revised accordingly. Additional figures are needed for both wetland rating forms. The following figures should be submitted with the revised wetland rating forms.  Map of hydroperiods and location of outlet(s) with 150’ buffer shown  Map of contributing basin  Screen capture of TMDLS for WRIA in which unit is found Wetland and Wetland Buffer Enhancement Plan Review The proposed wetland and wetland buffer enhancement plan is based on 50-foot wetland buffers. It is our professional evaluation that Wetlands A and B should be revised to Category III wetlands with 75-foot buffers. Changes to the buffer widths affect the buffer impact, averaging, and enhancement area totals provided in the plan. Per RMC 4-3-050(I)1, wetland buffer widths shall be reduced by no more than 25% of the required buffer. A 75-foot buffer cannot be reduced to less than 56.25 feet. Further reductions require review as a variance pursuant to RMC 4-9-250. Information needs to be provided by the applicant to demonstrate how the reduced buffer around Wetland A will function at a higher level than the Jill Ding, Senior Planner, City of Renton Page 5 Cherie Lane– Wetland Delineation and Classification Review May 12, 2017 5 standard buffer, and how the general mitigation process has been followed as required by RMC 4-3- 050(H)2. The proposed buffer impacts do not appear to meet the criteria listed at RMC 4-3-050(I)3a/b for reduction of buffer width with enhancement or buffer averaging. The applicant proposes to enhance 19,682 SF of wetland and buffer areas, and add 4,997 SF of additional buffer to Wetland A, to compensate for impacts to 9,727 SF of buffer. The RMC does not allow for enhancing wetlands to offset wetland buffer impacts. The proposed mitigation plan does not appear meet the individual requirements for either buffer reduction with enhancement or buffer averaging. In addition, the existing buffer areas proposed for enhancement are already forested, and it is not evident that the proposed enhancement plan would increase buffer functioning to achieve a no-net-loss of function as required per RMC 4-3-050(J)4a. Please feel free to contact me if you have any questions or concerns. Sincerely, Jeff Gray | Otak, Inc. c: 609.532.4620 jeff.gray@otak.com December 14, 2017 AOA-1773 Steve Beck Newfourth LLC 19244 39th Ave. S. SeaTac, WA 98188-5316 SUBJECT: Wetland Delineation and Classification for Cherie Lane (Revised) Parcel 302305-9108, Renton, WA Dear Steve: We have updated this critical areas report to incorporate the results of a site review meeting that was conducted on July 10, 2017 with Jill Ding, Senior Planner with the City of Renton and Jeff Gray, Senior Wetland Scientist with Otak, the City’s peer review consultant. Background On January 20, 2016 I conducted a wetland delineation on the undeveloped subject property utilizing the methodology outlined in the May 2010 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0). Additional field investigations were conducted on September 14 and November 1, 2016. Wetland Flags AA-4 through AA-8 were added during the July 10, 2017 site review meeting. These flags are intended to show the connection between Wetland Areas A and AA. 1.0 EXISTING WETLANDS One wetland (Wetland A) was identified as a mosaic throughout the central portion of the property. The wetland boundary (including the newer AA flags) was surveyed by Encompass Engineering & Surveying. A second wetland (Wetland B) is located off-site to the southeast. The approximate location of this wetland was taken from a map prepared by the Jay Group in 2010 (Attachment A) and the approximate location confirmed during the November 1, 2016 field review. It is my understanding that a third wetland has been identified by Sewall Wetland Consulting, Inc. off-site to the northeast. This wetland has also been added to the Encompass plans. DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Page 1 of 2 LUA16-000964 ADVISORY NOTES TO APPLICANT The following notes are supplemental information provided in conjunction with the administrative land use action. Because these notes are provided as information only, they are not subject to the appeal process for the land use action. Planning: (Contact: Jill Ding, 425-430-6598, jding@rentonwa.gov) 1. RMC section 4-4-030.C.2 limits haul hours between 8:30 am to 3:30 pm, Monday through Friday unless otherwise approved by the Development Services Division. 2. Commercial, multi-family, new single family and other nonresidential construction activities shall be restricted to the hours between seven o’clock (7:00) a.m. and eight o’clock (8:00) p.m., Monday through Friday. Work on Saturdays shall be restricted to the hours between nine o’clock (9:00) a.m. and eight o’clock (8:00) p.m. No work shall be permitted on Sundays. 3. Within thirty (30) days of completion of grading work, the applicant shall hydroseed or plant an appropriate ground cover over any portion of the site that is graded or cleared of vegetation and where no further construction work will occur within ninety (90) days. Alternative measures such as mulch, sodding, or plastic covering as specified in the current King County Surface Water Management Design Manual as adopted by the City of Renton may be proposed between the dates of November 1st and March 31st of each year. The Development Services Division’s approval of this work is required prior to final inspection and approval of the permit. 4. A National Permit Discharge Elimination System (NPDES) permit is required when more than one acre is being cleared. 5. The applicant may not fill, excavate, stack or store any equipment, dispose of any materials, supplies or fluids, operate any equipment, install impervious surfaces, or compact the earth in any way within the area defined by the drip line of any tree to be retained. 6. The applicant shall erect and maintain six foot (6') high chain link temporary construction fencing around the drip lines of all retained trees, or along the perimeter of a stand of retained trees. Placards shall be placed on fencing every fifty feet (50') indicating the words, “NO TRESPASSING – Protected Trees” or on each side of the fencing if less than fifty feet (50'). Site access to individually protected trees or groups of trees shall be fenced and signed. Individual trees shall be fenced on four (4) sides. In addition, the applicant shall provide supervision whenever equipment or trucks are moving near trees. 7. This permit is shall comply with the Bald and Golden Eagle Protection Act. The permitted is responsible for adhering to the U.S. Fish and Wildlife Service National Bald Eagle Management Guidelines (2007) and /or your U.S. Fish and Wildlife Service permit. Development Engineering: (Contact: Justin Johnson, 425-430-7291, jtjohnson@rentonwa.gov) 1. See Attached Development Engineering Memo dated April 16, 2018 Fire Authority: (Contact: Corey Thomas, 425-430-7024, cthomas@rentonwa.gov) 1. The fire flow requirement for a single family home is 1,000 gpm minimum for dwellings up to 3,600 square feet (including garage and basements). If the dwelling exceeds 3,600 square feet, a minimum of 1,500 gpm fire flow would be required. A minimum of one fire hydrant is required within 300-feet ADVISORY NOTES TO APPLICANT Page 2 of 2 LUA**-000*** of the proposed buildings and two hydrants if the fire flow goes up to 1,500 gpm. Additional fire hydrants and water mains are required to be added in order to meet minimum requirements. 2. Fire department apparatus access roadways are required to be a minimum of 20-feet wide fully paved, with 25-feet inside and 45-feet outside turning radius. Fire access roadways shall be constructed to support a 30-ton vehicle with 75-psi point loading. Access is required within 150-feet of all points on the buildings. Maximum grade of road shall not exceed 15 percent. 3. Both of the new proposed homes require the installation of an approved fire sprinkler system. Lot 1 requires sprinklers per city street ordinance for all homes on dead end streets over 500-feet long. Lot 2 requires sprinklers as they have asked for a variance on the proposed access roadway width from 20- feet down to 16-feet. Technical Services: (Contact: Amanda Askren, 425-430-7369, aaskren@rentonwa.gov) 1. No comments at this time. Community Services: (Contact: Leslie Betlach, 425-430-6619, lbetlach@rentonwa.gov) 1. Parks Impact fee applies. Police: (Contact: Cyndie Parks, 425-430-7521, cparks@rentonwa.gov) 1. No comments at this time. Building: (Contact: Craig Burnell, 425-430-7290, cburnell@rentonwa.gov) 1. Recommendations of the geotechnical report must be followed as a condition of building permits. DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT M E M O R A N D U M DATE:April 16, 2018 TO:Jill Ding, Senior Planner FROM:Justin Johnson, Civil Plan Reviewer SUBJECT:Cherie Lane Short Plat LUA16-000964 I have reviewed the application for Cherrie Short Plat located at 3400 Block Talbot Road South and have the following comments: EXISTING CONDITIONS The site is approximately 115,870 square feet in size and is rectangular in shape with a pan handle along the North West corner. The site is a vacant lot and is mostly forested with a wetland located along the east side of the lot. The site is fronted by Talbot Road South on the west side of the parcel and S 34th St along the east side of the parcel. WATER: The proposed development is within the City’s water service area and in the Talbot Hill 350- hydraulic zone. There is an existing 12-inch water main (see City water project plan no. W-0599) in Talbot Rd S. which can deliver a maximum flowrate of 3,700 gallons per minute. The static water pressure is about 109 psi at ground elevation of 96 feet. SEWER: The site is in the Soos Creek Water and Sewer District service area. STORM DRAINGE: The site currently contains is a vacant lot and there is no on-site stormwater conveyance system. There is an existing 18” piped conveyance system (R-22880E) on the north side of the lot that flows from east to west. STREETS: At this location Talbot Road South is a Collector Arterial with existing right of way width of 60 feet. Cherrie Lane Short Plat– LUA16-000964 Page 2 of 4 April 16, 2018 WATER COMMENTS The following improvements are required to be provided by the developer for the proposed project to provide water service to each lot. 1. The site is located within the City of Renton Hospital & South Talbot Hill Water Special assessment district. 2. A new 1-inch water service and meter will be required for each of the new lots. The meter will be installed by the City at a cost of $3,310.00. The water system development fee for the 1-inch meter is $3,486.00. 3. Per Renton Regional Authority’s review comments, a new hydrant will be required. If a fire sprinkler system is a required, a double check valve assembly shall be installed on the water supply line to a fire sprinkler system. 4. Applicant will need to extend an 8 inch water main within the driveway to service the proposed location of the new hydrant. 5. Civil plans for the water main improvements will be required and must be prepared by a professional engineer registered in the State of Washington. Please refer to City of Renton General Design and Construction Standards for Water Main Extensions as shown in Appendix J of the City’s 2012 Water System Plan. Adequate horizontal and vertical separations between the new water main and other existing and new utilities (storm sewer pipes and vaults, sanitary sewer, power, gas, electrical) shall be provided for the operation and maintenance of the water main 6. Applicant is required to provide and easement to the City of Renton for the installation of the new water main and the new hydrant as shown within lot 2. SEWER COMMENTS 1. Please contact Soos Creek water and Sewer district for Sewer Requirements. STORM DRAINAGE COMMENTS 1. A preliminary drainage plan and Technical Information Report (TIR) prepared by Encompass Engineering dated March 27, 2018 was submitted to the City as part of the site plan submittal. The site is located in the City’s Flow Control Duration Standard (Forested Site Conditions). The site is located in the Black River drainage basin. The TIR was completed in accordance with the standards found in the 2016 City of Renton Surface Water Design Manual. 2. Applicant has shown within the TIR that they will fall under the exemption for the flow control requirements to satisfy Core Requirement #3, Flow Control Facilities. Any additional revision to impervious surfaces may require re-evaluation of the exemption to core requirement 3. 3. Conveyance calculations were not provided in the preliminary TIR. Conveyance calculations shall be included in the final TIR to satisfy Core Requirement #4, Conveyance System. 4. The preliminary drainage plan shows a piped stormwater conveyance system in the Talbot Road that conforms to the City’s street standards. New storm drain shall be designed and sized in Cherrie Lane Short Plat– LUA16-000964 Page 3 of 4 April 16, 2018 accordance with the standards found in Chapter 4 of the 2017 RSWDM. Storm drain with a minimum diameter of 12” is required in the public right of way. 5. Applicant shall provide an easement to the City of Renton for the area within the driveway to allow the City of Renton to maintain all of their utilities. 6. Each new lot is subject to a stormwater system development charge. The 2017 SDC for stormwater is $1,718.00 per lot. Stormwater SDC fees are due at construction permit issuance. TRANSPORTATION/STREET COMMENTS 1. The 2017 transportation impact fee is $5,430.85 per single family home. The current property contains one mobile home dwelling, the developer will receive a credit of $3,215.64 for the existing mobile home and will be required to pay the remaining $2,215.21. Fees are payable at the time of building permit issuance for each individual home. 2. Talbot Road South is classified as a Collector Arterial with existing right of way width of 60 feet. As per RMC 4-6-060 the minimum ROW width required on a minor arterial is 83 feet for 2 lanes (94 feet for 3 lanes) with street improvements as per RMC 4-6-060. As per RMC 4-6-060, the half street frontage improvements will be required to be built Talbot Road frontage by the developer. 3. Right of way dedication of 11.5 feet is required. The applicant may submit a street modification, with the request to reduced cross section for Talbot Road. 4. Per RMC 4-4-080, the maximum width of a single loaded garage driveway is 9’ and the maximum width of a double loaded garage driveway is 16’. If a garage is not present, the maximum driveway width is 16’. Driveways shall not be closer than 5’ to any property line. Maximum slopes for driveways shall not exceed 15% provided that driveways exceeding 8% provide slotted drains at the lower end with positive drainage discharge to restrict runoff from entering the garage. 5. Per RMC 4-6-060, street lighting is not required since the project is less than four residential units. 6. The project does not require a Traffic Impact Analysis as the project produces less than 20 vehicles per hour in both the AM and PM peak periods. 7. Paving and trench restoration within the City of Renton right of way shall comply with the City’s Restoration and Overlay requirements. Cherrie Lane Short Plat– LUA16-000964 Page 4 of 4 April 16, 2018 GENERAL COMMENTS 1. The fees listed are for 2018. The fees that are current at the time of the respective permit issuance will be levied. Please see the City of Renton website for the current fee schedule. 2. Retaining walls that are 4’ or taller from bottom of footing and stormwater detention vaults will require a separate building permit. Structural calculations and plans prepared by a licensed engineer will be required as part of the building permit review. 3. All civil plans shall conform to the current City of Renton survey and drafting standards. Current drafting standards can be found on the City of Renton website. 4. A separate plan submittal will be required for a construction permit for utility work and street improvements. All plans shall be prepared by a licensed Civil Engineer in the State of Washington. 5. Please see the City of Renton Development Engineering website for the Construction Permit Application and Construction Permit Process and Submittal Requirements. Please contact the City to schedule a construction permit intake meeting. Report of Geological Engineering Services Proposed Property Development Coal Mine Hazard Assessment and Ground Proofing Program Newfourth LLC Property King County Parcel No. 302305-9108 Renton, Washington December 27, 2016 ICE File No. 1096-001 Prepared For: Newfourth LLC Prepared By: Icicle Creek Engineers, Inc.