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HomeMy WebLinkAboutSWP272795(1) 1 � BAIMA & HOLMBERG INC. D-CX-195 DRAINAGE REPORT FOR HONEY CREEK HEIGHTS 2 SHORT PLAT March 1, 1999 Baima& Holmberg, Inc., Job No. 725-003 City of Renton Project No. LUA-98-145-SHPL-H Prepared for PER ti'•f.sy, Bob Colwell R.C. Construction NW 2625 NE 27 Street Renton, WA 98056 :.�5 asp C' «iVAL.� �+ L v _ ExPIREs 1 3b Q ,100 FRONT STREET SOUTH ISSAQUAH WASHINGTON 98027-3817 (425) 392-0250 (425) 391-3055 � r PROJECT OVERVIEW This project involves developing a 1.22 acre parcel into six single-family lots. The site is located in the Devil's Elbow area, on the south side of SE 27t" Street, about 350 feet east of Edmonds Avenue NE. The site is on flat ground overlooking Honey Creek to the north, and is presently covered with one house, driveways and lawn. DRAINAGE PLAN Surface runoff will be collected in an onsite storm conveyance system and routed to a combination detention/water quality tank to be located adjacent to SE 27t" Street. This R/D facility will discharge into the existing ditch along 27t", the existing conditions site discharge point. � T November 12, 1998 OFFICE OF THE HEARING EXAMINER CITY OF RENTON REPORT AND DECISION {% APPLICANT: Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H LOCATION: 2625 NE 27th Street SUMMARY OF REQUEST: To subdivide 1.22 acre parcel into six lots for single family residential development. SUMMARY OF ACTION: Development Services Recommendation: Approve with conditions DEVELOPMENT SERVICES REPORT: The Development Services Report was received by the Examiner on October 30, 1998. PUBLIC HEARING: After reviewing the Development Services Report, examining available information or.file with the application, field checking the property and surrounding area;the Examiner conducted a public hearing on the subject as follows: MINUTES The following minutes are a summary of the November 3, 1998 hearing. The legal record is recorded on tape. The hearing opened on Tuesday,November 3, 1998, at 9:05 a.m. in the Council Chambers on the seventh floor of the Renton City Hall. Parties wishing to testify were affirmed by the Examiner. The following exhibits were entered into the record: Exhibit No. 1: Yellow file containing the original Exhibit No. 2: Vicinity map application, proof of posting, proof of publication and other documentation pertinent to this request. Exhibit No.3: Short plat map Exhibit No. 4: Map of neighboring properties The hearing opened with a presentation of the staff report by PETER ROSEN,Project Manager,Development Services, City of Renton, 1055 S Grady Way, Renton, Washington 98055. The applicant proposes to subdivide 1.22 acres into six lots for single family residential development. The site is located in the Devil's Elbow area of the City. NE 27th which abuts the site directly on the north, is closed as a through street and is gated just past the existing driveway into the site. To the north of the site across NE 27th are steep wooded Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H November 12, 1998 Page 2 slopes down to the Honey Creek drainage area. The site sits above NE 27th street and there is an embankment where the existing driveway enters the site and is the only point of access into the site without disturbance to the steep slopes. Access is proposed via an access easement along the west boundary of the site. That access easement is 26 feet with 20 feet of pavement and would provide access to lots 1 through 5. There is an existing 12 foot-wide private driveway on a 30 foot easement that cuts east-west across Lot 1 and is used as an ingress/egress and utility easement. That provides access to Lot 6 as well as three other existing adjacent properties to the east. The access is limited to the existing driveway off NE 27th. In addition, it is not very feasible for the applicant to provide the frontage road improvements along NE 27th as required by the code. It is impractical because of the steep topography to provide this improvement. The street improvement ordinance allows the Zoning Administrator to grant modifications and such was approved with conditions on October 2, 1998. Lot 1 at the north portion of the site would be 12,475 square feet, and lots 2 through 5 range between 5,300 and 6,638 square feet. Lot 6 at the south end of the site has an existing residence on it and is 15,990 square feet. The subject site is zoned R-8 which permits a density range of 5 to 8 dwelling units per acre. The density of this proposal is 4.93 dwelling units per acre. The code allows, however, the minimum density to be reduced provided the applicant can show that minimum density cannot be achieved due to lot configuration, lack of access or physical constraints. Because of the steep slopes, access is limited on this site. This site is designated RS on the Comprehensive Plan(CP) land use map and is intended to promote and enhance single family neighborhoods. This proposal is consistent with its designation. All lots meet the minimum lot size, as well as lot width and depth requirements. The applicant proposes a combined storm water detention/water quality vault to be located in the northeast corner of the site. To prevent additional runoff in this area, applicant is required to develop the system for additional storm water detention. The proposed short plat is expected to generate additional traffic and applicant is required to pay a traffic mitigation fee. Police and Fire have indicated sufficient resources exist to provide service to the proposed development, and applicant is required to pay a fire mitigation fee of$488 per single family lot. Additionally, a parks mitigation fee is required of this proposal in the amount of$530.76 per single family lot. Staff recommends approval of this short plat, subject to the following conditions: (1)that the applicant pay the required traffic,parks and fire mitigation fees; (2)that the storm water system be designed to meet the standards required by staff; (3)that the applicant record covenants for access and maintenance for private street easements for each of the lots that gain access or are affected by the proposed access easements; (4)that applicant record a covenant on all the lots for use and maintenance of a common storm water facility. Bob Colwell,2625 NE 27th Street, Renton, Washington 98056, applicant herein, concurred with the staff report. He stated that he is being required to provide a 20 foot asphalt road up the northern boundary of the property,then to the south to Lot 6. He contends that he should be able to stop at the point where the 30 foot easement comes in and use that as a private lane to service the two houses on the southerly portion of the property. He has also requested a change in the requirement for the hammerhead turnaround. There was discussion regarding requirements for a hammerhead and its location. Dave Christiansen, 2601 NE 27th, Renton, Washington 98056, an adjacent property owner, was concerned about the current easement that cuts across the corner of his property to access the easement to the existing lots, Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShPl-H November 12, 1998 Page 3 and the projected increase in its use. It was determined by the parties that the new driveway would not be on his property as presently designed. Shupe Holmberg, 100 Front Street S, Issaquah, Washington 98027, applicant engineer herein, stated that additional shrubs would be removed to widen NE 27th to meet required standards. Neil Watts, Plan Review Supervisor,Development Services Division, City of Renton, 1055 S. Grady Way, Renton, Washington 98055, stated that City code requires certain types of improvements for this type of short plat and included is widening of the existing road to 20 feet and improvements to NE 27th as it runs along the property. He listed the major concerns of the Fire Department for short plats such as this, and their requirements for hammerheads, road width and sprinkler systems. The Examiner called for further testimony regarding this project. There was no one else wishing to speak,and no further comments from staff. The hearing closed at 9:50 a.m. FINDINGS, CONCLUSIONS &DECISION Having reviewed the record in this matter,the Examiner now makes and enters the following: FINDINGS: 1. The applicant, Bob Colwell, filed a request for approval of a 6-lot short plat. 2. The yellow file containing the staff report,the State Environmental Policy Act(SEPA) documentation and other pertinent materials was entered into the record as Exhibit#1. 3. The Environmental Review Committee(ERC),the City's responsible official, determined that the proposal is exempt from an environmental assessment. 4. The subject proposal was reviewed by all departments with an interest in the matter. 5. The subject site is located at 2625 NE 27th Street. The site is located in the northeast corner of the City. The site is just south of Honey Creek and just west of the closure of the street known as Devil's Elbow. 6. The subject site was annexed to the City with the adoption of Ordinance 1796 enacted in October 1959. 7. The subject site is classified R-8 (Single Family Residential; 8 units/acre). 8. The map element of the Comprehensive Plan designates the area in which the subject site is located as suitable for the development of single family uses, but does not mandate such development without consideration of other policies of the Plan. 9. An existing single family home is located on the southernmost quarter of the site. Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H November 12, 1998 Page 4 10. The subject site is approximately 1.22 acres or 52,982 square feet. The parcel is fairly regular except that the northern property line follows the curve of NE 27th Street which follows the Honey Creek drainage contours. The parcel is approximately 170 feet wide (east to west)by 280 feet long. 11. The subject site drops steeply at NE 27th Street. The edge of the property forms a steep approximately 20 foot bank down to 27th. The remainder of the site is fairly level. 12. The applicant proposes dividing the subject site into six lots. The proposed lots will contain the following general dimensions: Length Width Square Footage Lot 1 170.0 120.0 12,475 Lot 2 75.0 88.5 6,638 Lot 3 75.0 82.17 6,163 Lot 4 100.0 64.16 6,416 Lot 5 75.0 70.67 5,300 Lot 6 170.71 100.0 15,990 The north boundary of Proposed Lot 1 will follow the curve.of NE 27th and will be generally triangular in shape. The remaining lots are generally rectangular. The existing home is located on what will be Proposed Lot 6. 13. Access to the site is via an easement driveway shared between the existing home and three other homes east of the site. Currently, the access enters the lot west of the subject site and then curves east into the subject site. The applicant proposes moving the access so that it is solely on the subject site. The applicant proposes dividing the current access roadway as it enters the site. Currently the access wraps around the north edge of the site and then down the eastern edge. It will continue this course and provide access to Proposed Lot 6. It will actually divide at the northeast corner of the site and continue east to access two homes. The south branch will run down the eastern edge of the site and provide the access to Proposed Lot 6 and a lot east of Lot 6. 14. Access to Proposed Lots 2, 3, 4 and 5 will be via another private access driveway along the western boundary of the site that branches off as the drive enters the site. A hammerhead turnaround will be created for access to Proposed Lots 2, 3,4 and 5. No additional hammmerhead was proposed by the applicant. Staff has recommended that roadway widths within the site be 20 feet and additional turnarounds be created for access to Proposed Lot 6 and the eastern lots. 15. A detention pond will be located on the northeast corner of the site and convey storm water to Honey Creek. Staff has requested additional storm water controls since there are already erosion problems in the Honey Creek streambed. 16. As proposed,the density will be approximately 4.93 dwelling units per acre. Code requires a density of between 5 and 8 dwelling units per acre. A reduction in density is permitted if the applicant demonstrates the requirements cannot be met due to lot configuration, access limitations or physical constraints. 17. NE 27th Street is substandard developed to a width of approximately 12 feet. Staff has permitted the reduced width to minimize as much as possible the cutting into the steep bank above NE 27th. For the Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShPl-H November 12, 1998 Page 5 same reasons they do not want additional cuts for access to the site from 27th Street. In exchange for this modification, staff required that 27th be widened to 20 feet which is still substandard but acceptable for emergency access. The approval of the modification also required driveways within the site be paved to 20 feet widths to rectify access limitations for emergency vehicles. 18. The applicant has requested that the existing substandard driveway conditions be maintained as legally non-conforming. Staff maintains that the four lots and residences be accessible by appropriately widened driveways. 19. Due to the location and the substandard access, staff also required that all new homes be provided with fire sprinkler systems. "Dead-end" streets are measured from the last point where two independent routes can converge to serve a site. In this case,Edmonds to the west is the measuring point for calculating the dead-end street. 20. To minimize the impacts of this development on Fire,Transportation and Recreational services, staff recommended that the fees usually assessed during environmental review be imposed on the subject site. The platting statutes allow a City to make sure plats provide for appropriate levels of urban services. 21. The development of the subject site will generate approximately 50 additional vehicle trips per day for the five new homes (one existing home is removed from the calculations). 22. The development will generate approximately 2 to 3 new students. They will be assigned to schools in the Renton School District on a space available basis. 23. It appears that in order to move the existing driveway, a hydrant will also have to be moved. 24. Apparently some information, particularly the location and configuration of homes and access to adjoining lots to the east, was requested by staff so that they could thoroughly review the layout of homes and access to those homes. This information was not provided by the applicant in a timely fashion. This made some of the information provided prior to and even at the public hearing incomplete. Issues of concern are Fire Department access and the need for additional turnaround sites. CONCLUSIONS: 1. The proposed plat appears to serve the public use and interest. While the plat's density falls below the mandated minimum, there are constraints which justify the density of approximately 4.93 dwelling units per acre. As proposed the site has five lots which lack frontage on a public street, has two private access roadways providing access to 8 separate dwellings (some offsite), and has topographical constraints that prevent any additional reasonable access to 27th Street. 2. The rather remote location and substandard dead-end access is not ideal for emergency access. Not only does it make reaching the site in the first place time-consuming and circuitous, but it makes leaving the site to access other locations in the event of any additional emergencies an additional problem. Therefore, staffs recommendations for 20 foot wide internal driveways and roadways are appropriate. In addition, hammerhead turnarounds, as many as required and approved by the Fire Department are also appropriate. It would be inappropriate for emergency vehicles to be delayed or trapped on the subject site by inadequate, further substandard roadways and turnarounds. Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H November 12, 1998 Page 6 3. State law requires new plats to make adequate provision for roads, schools, parks and emergency services. Therefore,the applicant shall pay appropriate fees for these services based on formulas already calculated by the City. 4. The proposed internal boundaries and generally rectilinear lots appear reasonable and as noted, while access is not ideal, it appears to provide reasonable access to the various parcels provided the appropriate width roadways and turnarounds are provided as noted above. 5. The development of the subject site will provide additional housing choices in a range of lot sizes in a rather private area of the City. Services can be provided to the site. 5. In conclusion, as conditioned to provide for fire protection by sprinklers and providing adequate access, the proposed Plat is approved. DECISION: The Proposed Plat is approved subject to the following conditions: 1. The applicant shall pay a traffic mitigation fee of$75 for each new average daily trip associated with the project. The traffic mitigation fee is estimated at$3,581.25 for the five new lots. 2. The applicant shall pay a fire mitigation fee equal to $488 per single family lot, for a total of$2,440.00 3. The applicant shall pay a parks mitigation fee of$530.76 per single family lot, for a total of$2,653.80. 4. The stormwater system shall be designed to meet the following standard: The release rate for the developed site shall be limited to 50% of the predeveloped 2 year 24 hour storm event through the 2 year storm event, with a safety factor of 10% in the detention volume. The release rates for the developed site shall be limited for the 5 year, 10 year, and 100 year storm event to the predeveloped rates for those events,with a 30% safety factor for the 100 year storm event. The stormwater system design shall be subject to the approval of the Development Services Division prior to recording of the short plat. 5. The applicant shall record covenants for access and maintenance of the private street easements for each of the lots that gain access or are affected by the proposed access easement. The covenant shall be subject to the approval of the Development Services Division prior to recording of the short plat. 6. The applicant shall record a covenant on all of the lots for use and maintenance of a common stormwater facility. The covenant shall be subject to the approval of the Development Services Division prior to recording of the short plat. 7. The applicant shall provide 20 foot wide internal driveways and roadways and hammerhead or other turnarounds, as required and approved by the Fire Department. f Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H November 12, 1998 Page 7 ORDERED THIS 12th day of November, 1998. FRED J. KAUF N HEARING EXAMINER TRANSMITTED THIS 12th day of November, 1998 to the parties of record: Peter Rosen Bob Colwell Dave Christiansen 1055 S Grady Way 2625 NE 27th 2601 NE 27th Renton, WA 98055 Renton,WA 98056 Renton, WA 98056 Shupe Holmberg . Neil Watts Henry Schlaht 100 S Front Street 1055 S Grady Way 2532 Ferndale Avenue NE Issaquah, WA 98027 Renton, WA 98055 Renton, WA 98056 TRANSMITTED THIS 12th day of November, 1998 to the following: Mayor Jesse Tanner Gregg Zimmerman, Plan/Bldg/PW Admin. Members,Renton Planning Commission Jim Hanson,Development Services Director Chuck Duffy,Fire Marshal Mike Kattermann,Technical Services Director Lawrence J. Warren, City Attorney Larry Meckling, Building Official Transportation Systems Division Jay Covington, Chief Administrative Officer Utilities System Division Councilperson Kathy Keolker-Wheeler Sue Carlson, Econ. Dev. Administrator South County Journal Pursuant to Title IV, Chapter 8, Section 15 of the City's Code, request for reconsideration must be filed in writing on or before 5.00 p.m.,November 30, 1998. Any aggrieved person feeling that the decision of the Examiner is ambiguous or based on erroneous procedure, errors of law or fact, error in judgment, or the discovery of new evidence which could not be reasonably available at the prior hearing may make a written request for a review by the Examiner within fourteen(14)days from the date of the Examiner's decision. This request shall set forth the specific ambiguities or errors discovered by such appellant, and the Examiner may, after review of the record, take further action as he deems proper. An appeal to the City Council is governed by Title IV, Chapter 8, Section 16,which requires that such appeal be filed with the City Clerk, accompanying a filing fee of$75.00 and meeting other specified requirements. Copies of this ordinance are available for inspection or purchase in the Finance Department, first floor of City Hall. If the Examiner's Recommendation or Decision contains the requirement for Restrictive Covenants,the executed Covenants will be required prior to approval by City Council or final processing of the file. You may contact this office for information on formatting covenants. Bob Colwell R.C. Construction NW RC Short Plat File No.: LUA-98-145,ShP1-H November 12, 1998 Page 8 The Appearance of Fairness Doctrine provides that no ex parte(private one-on-one) communications may occur concerning pending land use decisions. This means that parties to a land use decision may not communicate in private with any decision-maker concerning the proposal. Decision-makers in the land use process include both the Hearing Examiner and members of the City Council. All communications concerning the proposal must be made in public. This public communication permits all interested parties to know the contents of the communication and would allow them to openly rebut the evidence. 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M N F- T IF1 / 17: ♦ c • 50 t4A U r ...... he ♦ g 1 e r t PROJECT OVERVIEW This project involves subdividing a 1.21 acre parcel into 6 single-family residential lots. The site is located along the south side of N.E. 27th Street, in the NW % of Section 4 of Township 23 North, Range 5 East. The existing conditions consists of lawn and a single family residence with underlying Alderwood and Indianola soils. UPSTREAM TRIBUTARY AREA Approximately 0.20 acres of residential lawns drains onto the site from the west. There are no apparent drainage problems associated with these flows. LEVEL 1 DRAINAGE ANALYSIS The on-site runoff flows from south to north across the site and drains down a steep slope into an existing drainage ditch along the south side of N.E. 27th Street. There is no apparent erosion down the slope due to heavy vegetation. The ditch has moderate erosion with an approximate bottom width and depth of 1.0' and 1.5'. The runoff continues in the ditch flowing east at an approximate grade of 2% to 5% for about 400' where it drains into a 15" diameter culvert. The culvert conveys the runoff approximately 50' north crossing N.E. 27th Street and discharges approximately 4' above the ground. From the culvert, the runoff flows north approximately 300' in a channel located in the bottom of a heavily vegetated ravine that drains into May Creek. The channel slopes northeast at about a 40% grade and has an approximate bottom width and depth of 2' and 1.5' with cobbles and earth lining. There is no apparent erosion due to the heavy vegetation along the channel. Once the runoff drains into May Creek, it continues northwest in the creek further than a % mile downstream. There are no apparent capacity problems along this downstream drainage path. The proposed storm system consists of conveying the on-site runoff into a detention/water quality vault. 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OF 100 Front Street South 2 DATE ISSAQUAH, WASHINGTON 98027-3817 CALCULATED BY (425) 392-0250 FAX (425) 391-3055 CHECKED BY DATE SCALE Z WR-� QU�4c-L Al2�A 3�` q�F ..�:._ $ E>,S S�I�r wt L�1T" Sl t rg F V OLU,.►tit a 0-0 'iJeD . . . . z . Q)l ... .__.__ �... b/1lt � Zc 13f r t Cr � 7g6C o K- PRODUCT 2D4-1(Single Sheets)205-1(Padded). JOB �ZS or 3 BAIMA & HOLMBERG, INC. SHEET NO. OF 100 Front Street South Z� DATE ISSAQUAH, WASHINGTON 98027-3817 CALCULATED BY- (425) 392-0250 FAX (425) 391-3055 CHECKED BY DATE SCALE a TZ. J7F5 N ... �:25 �N ... QA....I�./..14 .... � ....... .__ .. _... .ram '. '. q :... ......... ....... _. .................. .. .. � - 3.Zp .(, D,t_g 3.01 . ......... D `f PRODUCT 204-1(Singh Sheets)205-1(PaM) CUSTOM STAGE vs. STORAGE TABLE PIPE DIA. (ft) = 10 SEDIMENT STORAGE AREA (ft^2) = 1.47 DEAD STORAGE DEPTH (ft) = 2.5 DEAD STORAGE AREA (ft^2) = 13.89 SEDIMENT DEPTH (ft) = 0.5 LENGTH OF PIPE (ft) = 70 LIVE LIVE DEPTH (ft) AREA (ft^2) VOLUME (ft-3) 2.50 1.47 102.8 2.80 4.12 288.1 3.10 6.85 479.6 3.40 9.66 676.3 3.70 12.53 877.2 5.45 29.88 2091.4 5.50 30.38 2126.3 5.80 33.35 2334.4 6.00 35.32 2472.1 6.10 36.29 2540.6 6.40 39.20 2743.9 6.70 42.05 2943.5 7.00 44.84 3138.6 8.00 53.47 3743.0 9.00 60.57 4239.6 10.00 64.65 4525.7 f ) ---------------------------------------------------------------------- ******************** S .C. S . TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2 . 00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 .2 1 . 1 68 . 0 . 1 98 . 0 26 . 7 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) . 04 7 . 83 1431 ---------------------------------------------------------------------- ******************** S .C. S. TYPE-lA DISTRIBUTION ******************** ********* 5-YEAR 24-HOUR STORM **** 2 . 40" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 .2 1 . 1 68 . 0 . 1 98 . 0 26 .7 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) . 05 8 . 00 1 2186 ---------------------------------------------------------------------- ******************** S .C. S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2 . 90" TOTAL PRECIP. ********* ---------- ----- ---------------------- --------- ------------------------ DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 . 2 1 . 1 68 . 0 . 1 98 . 0 26 . 7 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) . 09 8 . 00 3298 ---------------------------------------------------------------------- ******************** S.C. S . TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3 . 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 .2 1 . 1 68 . 0 .1 98 . 0 26 . 7 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) .22 7 . 83 5947 -------------------- -------------------------------------------------- ******************** S .C. S . TYPE-lA DISTRIBUTION ******************** ********* 1-YEAR 24-HOUR STORM **** . 67" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 . 2 . 7 68 . 0 . 6 98 . 0 15 . 0 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) . 06 7 . 83 946 ---------------------------------------------------------------------- ******************** S.C. S . TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2 . 00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 .2 . 7 68 . 0 . 6 98 . 0 15 . 0 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) .23 7 . 83 4007 ---------------------------------------------------------------------- ******************** S .C.S . TYPE-lA DISTRIBUTION ******************** ********* 5-YEAR 24-HOUR STORM **** 2 .40" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 .2 . 7 68 . 0 . 6 98 . 0 15 . 0 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) . 28 7 . 83 5163 ---------------------------------------------------------------------- ******************** S .C. S . TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2 . 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 . 2 . 7 68 . 0 . 6 98 . 0 15 . 0 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) .37 7 . 83 6714 ---------------------------------------------------------------------- ******************** S .C.S . TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3 . 90" TOTAL PRECIP. ********* ----------------------------- ----------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC (MINUTES) A CN A CN 1 . 2 . 7 68 . 0 . 6 98 . 0 15 . 0 PEAK-Q (CFS) T-PEAK(HRS) VOL (CU-FT) .58 7 . 83 10075 PERFORMANCE : INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD: . 58 .20 . 19 7 . 49 3517 TEST HYD 1 : . 37 . 09 . 09 7 . 34 3500 TEST HYD 2 : .28 . 05 . 05 7 . 29 3490 TEST HYD 3 : . 23 . 02 . 02 5 . 70 2970 STRUCTURE DATA: R/D TANK (FLAT GRADE) RISER-HEAD TANK-DIAM STOR-DEPTH TANK-LENGTH STORAGE-VOLUME 7 . 50 FT 10 . 00 FT 7 . 50 FT 55 . 7 FT 3517 CU-FT DOUBLE ORIFICE RESTRICTOR: DIA(INCHES) HT (FEET) Q-MAX (CFS) BOTTOM ORIFICE : . 52 . 00 . 020 TOP ORIFICE: 3 . 64 7 .25 . 180 ROUTING DATA: STAGE (FT) DISCHARGE (CFS) STORAGE (CU-FT) PERM-AREA(SQ-FT) . 00 . 00 . 0 . 0 . 75 . 01 . 0 . 0 1 .50 . 01 . 0 . 0 2 . 25 . 01 1192 . 7 • 0 3 . 00 . 01 1609 . 9 • 0 3 . 75 . 01 2020 . 8 . 0 4 . 50 . 02 2415 . 3 . 0 5 .25 . 02 2782 .3 • 0 6 . 00 . 02 3107 . 6 • 0 6 . 75 . 02 3370 . 0 , 0 7 .25 . 02 3489 . 9 . 0 7 . 50 . 20 3519 . 0 . 0 7 . 60 . 54 3519 . 0 • 0 7 . 70 1 . 13 3519 . 0 • 0 7 . 80 1 . 89 3519 . 0 . 0 7 . 90 2 . 70 3519 . 0 • 0 8 . 00 3 . 01 3519 . 0 . 0 AVERAGE VERTICAL PERMEABILITY: . 0 MINUTES/INCH