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HomeMy WebLinkAbout5_Street Standards Modification Request_21211_Larsen Develoment_20240718P:\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\_Working Components & Ref\2024.07.18_5_21211_Larsen Develoment_Street Standards Modification Request.doc July 18, 2024 VIA Email: SAMorman@rentonwa.gov Samuel Morman, Civil Engineer II City of Renton 1055 S Grady Way Renton, WA 98057 RE: Larsen Development (PRE21-000277) – Modification to Street Standards 2211 Williams Ave S., Renton, WA 98055 Parcel No: 7222000087 Dear Sam, This letter, along with the supplemental materials included, are provided in support of modification requests to the following standards: Modification Requests to RMC 4-6-060 Street Standards Standard F. Public Street Right-of-Way Design Standards: Excerpt from PRE21-000277 dated August 19, 2021 Modification Request 1: Please refer to Attachment 1 - Williams Ave S Road Cross Section Exhibit to aid in the following description. The available width for improvements on Williams Avenue South is limited due to constraints of existing retaining walls to the east (along Benson Highway) which provides less than the minimum 24-feet half-street required to install the standard improvements. The project is requesting modifications to reduce, and reconfigure, the standard landscape planter to accommodate site conditions. It is proposed that the standard 8-foot-wide landscape planter between the back of curb and sidewalk be modified for the following scenarios: 1) Reduced to 7.5-feet wide from approx. Section 0+35 to 1+25. This allows 6-inches behind the sidewalk to right-of-way/property line for some minor slope grading or installation of a short curb if needed. 2) Reduced to varying widths and relocated to back of sidewalk from approx. Section 1+25 to 2+05. This allows for 4+ feet of grade to be made up behind the back of sidewalk instead of steep slope grading (2H:1V or steeper) within a landscape strip between sidewalk and curb. Note that some areas will require a landscape wall (non- structural) less than 4 feet exposed. Standard H. Dead End Streets: Dead end roads over 300-feet shall have a full 90-foot diameter cul-de-sac. Lacey Seattle Engineering & Planning 14900 Interurban Ave. S Suite 279 Seattle, WA 98168-4635 Ph: 206.674.4659 www.patrickharron.com July 18, 2024 Page 2 of 6 P:\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\_Working Components & Ref\2024.07.18_5_21211_Larsen Develoment_Street Standards Modification Request.doc Modification Request 2: Since no new lots will be created and only a shared driveway is proposed for access (over existing driveway), it is requested that the driveway be located within an easement instead of a tract. This would eliminate the need for platting through the Land Use process for creation of a tract. Although the Land Use process for platting would not be required with this scenario, stormwater review/management will be provided at the level required for a residential subdivision in accordance with the 2022 Renton Stormwater Design Manual; in particular, Section 1.2.3.1.B in reference to target surfaces. Preliminary storm drainage drawings and calculations provided with this Modification Request. Please refer to Attachment 3 – C3.1 Storm Drainage Plans & Preliminary Storm Calculations. Waiver Request: A hammerhead turnaround is proposed instead of a cul-de-sac. Preliminary approval for hammerhead with conditions for installation of fire sprinklers for all new homes received from Corey Thomas, Office of the Fire Marshal Lead Plans Review Inspector (see Attachment 2 – Preliminary Fire Marshal Approval via Email). Civil Construction Permit Plans will include conditions for fire sprinkler systems on all new homes. Standard J.4. Tract Required: Shared driveway shall be wholly within a tract. Justification for the Modification Request: RMC 4-9-250 D.2. Decision Criteria: Whenever there are practical difficulties involved in carrying out the provisions of this Title, the Department Administrator may grant modifications for individual cases provided he/she shall first find that a specific reason makes the strict letter of this Code impractical, that the intent and purpose of the governing land use designation of the Comprehensive Plan is met and that the modification is in conformity with the intent and purpose of this Code, and that such modification: a. Substantially implements the policy direction of the policies and objectives of the Comprehensive Plan Land Use Element and the Community Design Element and the proposed modification is the minimum adjustment necessary to implement these policies and objectives; Response: The property has a Comprehensive Plan Land Use Designation of Residential Medium Density (MD) and a zoning designation of Residential-8 (R-8). The project substantially implements the policies and objectives of the Comprehensive Plan Land Use Element and Community Design Element. The proposed modifications are the minimum adjustment necessary to implement these policies and objectives. b. Will meet the objectives and safety, function, appearance, environmental protection and maintainability intended by the Code requirements, based upon sound engineering judgment; Response: The proposed modifications would result in improvements that meet the objectives and safety, function, appearance, environmental protection and maintainability intended by the Code requirements, based upon sound engineering judgment. c. Will not create substantial adverse impacts to other property(ies) in the vicinity; Response: It is unlikely that the proposed improvements will create adverse impacts to other properties in the vicinity. d. Conforms to the intent and purpose of the Code; July 18, 2024 Page 3 of 6 P:\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\_Working Components & Ref\2024.07.18_5_21211_Larsen Develoment_Street Standards Modification Request.doc Response: The proposed modifications conform to the intent and purpose of the Code. e. Can be shown to be justified and required for the use and situation intended; Response: The proposed improvements are justified and required for the use and situation intended. Justification provided in previous responses. Attachments: Sincerely, Patrick Harron & Associates, LLC Schwin Chaosilapakul, PE CC: Greg Larsen (Owner) February 19, 2024 Page 4 of 6 \\PHA-S19A\Company\Projects & Project Data\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\21211_Larsen Develoment_Access Easement & Street Modification Request.doc ATTACHMENT 1 - Williams Ave S Road Cross Section Exhibit 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 210 220 230 240 210 220 230 240 0 20 400-20-40 210 220 230 240 210 220 230 240 0 20 400-20-40 WILLIAMS AVE SROADWAY SECTIONS(STA 1+20 - 2+00)---- 1 STA 1+20.00 STA 1+30.00 STA 1+40.00 STA 1+50.00 STA 1+60.00 STA 1+70.00 STA 1+80.00 STA 1+90.00 STA 2+00.00 OF SCALE: DATE: DRAWING NO. CHK. BY:DWN. BY: PROJ. NO.DSN. BY:R#DATEBYDESCRIPTIONCivil Engineering & PlanningWeb : patrickharron.com14900 Interurban Ave. S, Suite 279, Seattle, WA 98168Phone : 206.674.4659 21211 SC SC 2LARSEN DEVELOPMENTLARSEN DEVELOPMENT2211 WILLIAMS AVE SRENTON, WA 98055LARSEN DEVELOPMENT SE 1/4, SE 1/4, SEC 19, T 23 N, R 05 E, W. M.CITY OF RENTON - MODIFICATIONCC AS SHOWN 2/20/24 CALL 48 HOURS 811 BEFORE YOU DIG 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 215 220 230 240 215 220 230 240 0 20 400-20-40 WILLIAMS AVE SROADWAY SECTIONS(STA 0+30 - 1+10)---- 2 OF SCALE: DATE: DRAWING NO. CHK. BY:DWN. BY: PROJ. NO.DSN. BY:R#DATEBYDESCRIPTIONCivil Engineering & PlanningWeb : patrickharron.com14900 Interurban Ave. S, Suite 279, Seattle, WA 98168Phone : 206.674.4659 21211 SC SC 2LARSEN DEVELOPMENTLARSEN DEVELOPMENT2211 WILLIAMS AVE SRENTON, WA 98055LARSEN DEVELOPMENT SE 1/4, SE 1/4, SEC 19, T 23 N, R 05 E, W. M.CITY OF RENTON - MODIFICATIONCC AS SHOWN 2/20/24 CALL 48 HOURS 811 BEFORE YOU DIG February 19, 2024 Page 5 of 6 \\PHA-S19A\Company\Projects & Project Data\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\21211_Larsen Develoment_Access Easement & Street Modification Request.doc ATTACHMENT 2 - Preliminary Fire Marshal Approval via Email 1 Schwin Chaosilapakul From:Corey Thomas <cthomas@rentonrfa.org> Sent:Friday, October 27, 2023 1:45 PM To:Kimberly Senske Subject:RE: Larsen Development (Project #PRE21-000277) Kim, The Renton Regional Fire Authority will approve the use of approved fire sprinkler systems in all new homes in the proposed short plat and allow an approved hammerhead type turnaround instead of the usual full cul-de-sac. Hope to see your revised construction plans soon. Corey Thomas, Lead Plans Review Inspector Renton Regional Fire Authority l Office of the Fire Marshal Fire Plans Review Section 18002 108th Ave SE Renton, WA 98055 W: 425-276-9582 cthomas@rentonrfa.org Professionalism . Integrity . Leadership . Loyalty . Accountability . Respect From: Kimberly Senske <kim@PatrickHarron.com> Sent: Friday, October 27, 2023 12:22 PM To: Corey Thomas <cthomas@rentonrfa.org> Cc: Schwin Chaosilapakul <Schwin@PatrickHarron.com> Subject: Larsen Development (Project #PRE21-000277) Hi, Corey, I appreciate you taking the time to talk with me about the Larsen development. Since all houses will be sprinkled, we are proposing a hammerhead turn-around as a modification to the required Cul-de-Sac. Our plans will have a note stating that all houses will be sprinkled per your request as well. Please let me know if you need any additional information or documentation. I sincerely thank you for your help. Best, You don't often get email from kim@patrickharron.com. Learn why this is important 2 Kimberly Senske Project Manager Patrick Harron & Associates, LLC 14900 Interurban Avenue S, Suite 279 Seattle, WA 98168 360-979-6273 February 19, 2024 Page 6 of 6 \\PHA-S19A\Company\Projects & Project Data\2021\21211_Larsen Development - Renton\Text\Applications\Modification Documents\21211_Larsen Develoment_Access Easement & Street Modification Request.doc ATTACHMENT 3 - C3.1 Storm Drainage Plans & Preliminary Storm Calculations. WILLIAMSAVE SBENSONHWYS 23RD ST STORM DRAINAGE PLAN STORM DRAINAGE CALLOUTS: UTILITY CALLOUTS: RETAINING WALL CALLOUTS: NO.REVISION BY DATE APPR VERTICAL: NAVD 1988 IF NOT ONE INCH ONE INCH AT FULL SCALE HORIZONTAL: NAD 1983/1991 SCALE ACCORDINGLY Planning/Building/Public Works Dept. CITY OF RENTON IN COMPLIANCE WITH CITY OF RENTON STANDARDS LARSEN DEVELOPMENT SE 1/4 , SE 1/4, SEC 19, T 23 N, R 05 E, W. M.TED-40-4263LARSEN DEVELOPMENT-CIVIL CONSTRUCTION PERMITC23002334LUAXXXXXXXXPRE21-00027703/01/24 --- --- 11 LARSEN DEVELOPMENT CIVIL CONSTRUCTION PERMIT 2211 WILLIAMS AVE S, RENTON, WA. 98055 --- SC CC SC SCWWP-27-4263WTR-27-42630 20 40 N MATCHLINE - STA 0+50.00 MATCHLINE - STA 0+50.00C3.1--- --- 6 1"=20' C3.1STORM DRAINAGE PLAN S-426305 W-426305 R-426305 MATCHLINE - BELOW RIGHT MATCHLINE - ABOVE LEFT 21211_ Larsen Development Detention Scenario – 6.5’ Storage Depth Proposed Impervious for Lots 1 - 4 + Offsite Improvements Frontage Description – Includes new impervious surfaces for improvements to Williams Ave S. and S. 23rd St. Properties (Lots 1-4) - Assumed 4,000 sf for each lot (3,600 sf roof and 400 sf driveway), plus portions of the shared driveway (within access easement) crossing lots 1, 2, and 4. Site Location: According to the 2021 King County SWDM, target impervious surfaces only include existing impervious surfaces added on or after January 8th, 2001. According to past satellite imagery, the existing structures and asphalt driveway were present in the year 2000, so they predate the date in question. Those impervious areas are included in the Predeveloped modeling accordingly, with the remainder of tributary areas modeled as Historic Forest. Additionally, per the 2022 Renton SWDM, “The City of Renton does not require including existing impervious surfaces added on or after January 8th, 2001 in the definition of target impervious surfaces.” Our current design is conservatively taking credit only for those existing impervious surfaces that were present on site prior to the year 2001. Aerial Image of Property – Year 2000 Aerial Image of Property – Year 2021 Predeveloped Project Area * See Predeveloped Area Exhibit, attached Proposed Project Area: Detention Vault Specifications (Minimum): Detention Volume: Required: 6,580 cf (0.151 ac-ft) Provided: 6,643 cf (0.152 ac-ft) 42’L x 24.3’W x 4’D > 6,580 cf  OK Flow Frequency: Stream Duration: Area Summary: Hard Surface** Pervious Total* Hard Surface** Pervious Total A* Lot 1 5,000 5,668 10,668 0.115 0.130 0.245 B* Lot 2 5,490 5,610 11,100 0.126 0.129 0.255 C* Lot 3 4,000 5,150 9,150 0.092 0.118 0.210 D* Lot 4 6,617 5,110 11,727 0.152 0.117 0.269 E-H** Frontage (N/A) 3,881 972 4,853 0.089 0.022 0.111 --- Total 24,988 22,510 47,498 0.574 0.517 1.090 **Breakout Shown in Tables Below. Label Description Area (sf)Area (ac) *Assuming future development of 4,000 sf per lot in addition to shared driveway. (3,600 sf Roof and 400 sf Driveway) Remainder assumed lawn. Road Roof Drive Walk Pervious Total Lot 1 1,000 3,600 400 0 5,668 10,668 Lot 2 1,490 3,600 400 0 5,610 11,100 Lot 3 0 3,600 400 0 5,150 9,150 Lot 4 2,617 3,600 400 0 5,110 11,727 Frontage 2,085 0 0 1,796 534 4,415 Total 7,192 14,400 1,600 1,796 22,072 47,060 Description Proposed New + Replaced Hard Surface Area Inventory (sf) WQ Sizing: Minimum WQ Volume = 0.0696 ac-ft (3,032 cf) Proposed Volume = 0.0937 ac-ft (4,082 cf - 42’L x 24.3’W x 4’D) > 0.0696 ac-ft  OK WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: 21211_4000sf Prop_Ex.Predev_6.5'D Site Name: 21211_Larsen Site Address: 2211 Williams Ave S City : Renton, WA 98055 Report Date: 2/27/2024 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.00 Version Date: 2022/12/14 Version : 5.0.0 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ LAND USE Name : Existing w/ Forest Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Mod .804 Pervious Total 0.804 Impervious Land Use acre ROADS FLAT 0.161 ROOF TOPS FLAT 0.103 SIDEWALKS FLAT 0.022 Impervious Total 0.286 Basin Total 1.09 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : 4,000 SF LOTS + IMPROVEMENTS Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Mod .516 Pervious Total 0.516 Impervious Land Use acre ROADS FLAT 0.117 ROADS MOD 0.048 ROOF TOPS FLAT 0.331 DRIVEWAYS FLAT 0.037 SIDEWALKS MOD 0.041 Impervious Total 0.574 Basin Total 1.09 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Detention Vault Detention Vault ___________________________________________________________________ Name : Detention Vault Width : 31.818280686907 ft. Length : 31.818280686907 ft. Depth: 7.5 ft. Discharge Structure Riser Height: 6.5 ft. Riser Diameter: 18 in. Notch Type: Rectangular Notch Width: 0.010 ft. Notch Height: 2.230 ft. Orifice 1 Diameter: 1.041 in. Elevation: 0 ft. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Vault Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.023 0.000 0.000 0.000 0.0833 0.023 0.001 0.008 0.000 0.1667 0.023 0.003 0.012 0.000 0.2500 0.023 0.005 0.014 0.000 0.3333 0.023 0.007 0.017 0.000 0.4167 0.023 0.009 0.019 0.000 0.5000 0.023 0.011 0.020 0.000 0.5833 0.023 0.013 0.022 0.000 0.6667 0.023 0.015 0.024 0.000 0.7500 0.023 0.017 0.025 0.000 0.8333 0.023 0.019 0.026 0.000 0.9167 0.023 0.021 0.028 0.000 1.0000 0.023 0.023 0.029 0.000 1.0833 0.023 0.025 0.030 0.000 1.1667 0.023 0.027 0.031 0.000 1.2500 0.023 0.029 0.032 0.000 1.3333 0.023 0.031 0.034 0.000 1.4167 0.023 0.032 0.035 0.000 1.5000 0.023 0.034 0.036 0.000 1.5833 0.023 0.036 0.037 0.000 1.6667 0.023 0.038 0.038 0.000 1.7500 0.023 0.040 0.038 0.000 1.8333 0.023 0.042 0.039 0.000 1.9167 0.023 0.044 0.040 0.000 2.0000 0.023 0.046 0.041 0.000 2.0833 0.023 0.048 0.042 0.000 2.1667 0.023 0.050 0.043 0.000 2.2500 0.023 0.052 0.044 0.000 2.3333 0.023 0.054 0.044 0.000 2.4167 0.023 0.056 0.045 0.000 2.5000 0.023 0.058 0.046 0.000 2.5833 0.023 0.060 0.047 0.000 2.6667 0.023 0.062 0.048 0.000 2.7500 0.023 0.063 0.048 0.000 2.8333 0.023 0.065 0.049 0.000 2.9167 0.023 0.067 0.050 0.000 3.0000 0.023 0.069 0.050 0.000 3.0833 0.023 0.071 0.051 0.000 3.1667 0.023 0.073 0.052 0.000 3.2500 0.023 0.075 0.053 0.000 3.3333 0.023 0.077 0.053 0.000 3.4167 0.023 0.079 0.054 0.000 3.5000 0.023 0.081 0.055 0.000 3.5833 0.023 0.083 0.055 0.000 3.6667 0.023 0.085 0.056 0.000 3.7500 0.023 0.087 0.056 0.000 3.8333 0.023 0.089 0.057 0.000 3.9167 0.023 0.091 0.058 0.000 4.0000 0.023 0.093 0.058 0.000 4.0833 0.023 0.094 0.059 0.000 4.1667 0.023 0.096 0.060 0.000 4.2500 0.023 0.098 0.060 0.000 4.3333 0.023 0.100 0.061 0.000 4.4167 0.023 0.102 0.063 0.000 4.5000 0.023 0.104 0.065 0.000 4.5833 0.023 0.106 0.068 0.000 4.6667 0.023 0.108 0.071 0.000 4.7500 0.023 0.110 0.074 0.000 4.8333 0.023 0.112 0.077 0.000 4.9167 0.023 0.114 0.080 0.000 5.0000 0.023 0.116 0.083 0.000 5.0833 0.023 0.118 0.086 0.000 5.1667 0.023 0.120 0.090 0.000 5.2500 0.023 0.122 0.093 0.000 5.3333 0.023 0.124 0.097 0.000 5.4167 0.023 0.125 0.101 0.000 5.5000 0.023 0.127 0.105 0.000 5.5833 0.023 0.129 0.109 0.000 5.6667 0.023 0.131 0.114 0.000 5.7500 0.023 0.133 0.133 0.000 5.8333 0.023 0.135 0.139 0.000 5.9167 0.023 0.137 0.145 0.000 6.0000 0.023 0.139 0.152 0.000 6.0833 0.023 0.141 0.158 0.000 6.1667 0.023 0.143 0.164 0.000 6.2500 0.023 0.145 0.171 0.000 6.3333 0.023 0.147 0.178 0.000 6.4167 0.023 0.149 0.185 0.000 6.5000 0.023 0.151 0.192 0.000 6.5833 0.023 0.153 0.574 0.000 6.6667 0.023 0.154 1.267 0.000 6.7500 0.023 0.156 2.131 0.000 6.8333 0.023 0.158 3.076 0.000 6.9167 0.023 0.160 4.007 0.000 7.0000 0.023 0.162 4.834 0.000 7.0833 0.023 0.164 5.489 0.000 7.1667 0.023 0.166 5.950 0.000 7.2500 0.023 0.168 6.268 0.000 7.3333 0.023 0.170 6.665 0.000 7.4167 0.023 0.172 6.982 0.000 7.5000 0.023 0.174 7.284 0.000 7.5833 0.023 0.176 7.574 0.000 7.6667 0.000 0.000 7.853 0.000 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Landuse Totals for POC #1 Total Pervious Area:0.804 Total Impervious Area:0.286 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:0.516 Total Impervious Area:0.574 ___________________________________________________________________ Flow Frequency Return Periods for . POC #1 Return Period Flow(cfs) 2 year 0.121561 5 year 0.156721 10 year 0.180989 25 year 0.212859 50 year 0.237519 100 year 0.262993 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.051684 5 year 0.07581 10 year 0.095379 25 year 0.124692 50 year 0.150202 100 year 0.179163 ___________________________________________________________________ Stream Protection Duration Annual Peaks for and Mitigated. POC #1 Year Mitigated 1949 0.169 0.047 1950 0.153 0.051 1951 0.118 0.101 1952 0.084 0.040 1953 0.085 0.042 1954 0.102 0.043 1955 0.108 0.057 1956 0.106 0.050 1957 0.133 0.050 1958 0.098 0.047 1959 0.093 0.044 1960 0.127 0.087 1961 0.111 0.047 1962 0.084 0.036 1963 0.107 0.046 1964 0.098 0.044 1965 0.129 0.049 1966 0.090 0.037 1967 0.153 0.054 1968 0.152 0.041 1969 0.109 0.046 1970 0.116 0.043 1971 0.130 0.047 1972 0.145 0.060 1973 0.082 0.042 1974 0.121 0.039 1975 0.139 0.055 1976 0.105 0.044 1977 0.093 0.035 1978 0.113 0.047 1979 0.155 0.037 1980 0.180 0.060 1981 0.120 0.042 1982 0.183 0.101 1983 0.131 0.050 1984 0.091 0.040 1985 0.114 0.045 1986 0.126 0.078 1987 0.152 0.084 1988 0.092 0.041 1989 0.115 0.033 1990 0.281 0.103 1991 0.201 0.097 1992 0.092 0.042 1993 0.072 0.044 1994 0.077 0.030 1995 0.107 0.050 1996 0.156 0.097 1997 0.134 0.109 1998 0.107 0.043 1999 0.217 0.060 2000 0.121 0.046 2001 0.119 0.036 2002 0.146 0.080 2003 0.139 0.037 2004 0.206 0.234 2005 0.117 0.052 2006 0.107 0.050 2007 0.237 0.153 2008 0.203 0.188 2009 0.143 0.061 ___________________________________________________________________ Stream Protection Duration Ranked Annual Peaks for and Mitigated. POC #1 Rank Mitigated 1 0.2810 0.2342 2 0.2371 0.1881 3 0.2168 0.1526 4 0.2057 0.1090 5 0.2031 0.1031 6 0.2008 0.1008 7 0.1833 0.1007 8 0.1803 0.0974 9 0.1688 0.0973 10 0.1564 0.0872 11 0.1553 0.0844 12 0.1529 0.0795 13 0.1528 0.0777 14 0.1525 0.0606 15 0.1516 0.0603 16 0.1458 0.0598 17 0.1446 0.0596 18 0.1426 0.0568 19 0.1393 0.0550 20 0.1389 0.0545 21 0.1340 0.0524 22 0.1334 0.0509 23 0.1310 0.0502 24 0.1297 0.0499 25 0.1286 0.0499 26 0.1267 0.0496 27 0.1256 0.0496 28 0.1212 0.0486 29 0.1209 0.0472 30 0.1196 0.0472 31 0.1190 0.0471 32 0.1183 0.0467 33 0.1166 0.0466 34 0.1161 0.0464 35 0.1154 0.0458 36 0.1143 0.0455 37 0.1135 0.0454 38 0.1109 0.0441 39 0.1086 0.0441 40 0.1077 0.0440 41 0.1071 0.0436 42 0.1068 0.0433 43 0.1067 0.0431 44 0.1065 0.0430 45 0.1056 0.0423 46 0.1050 0.0418 47 0.1022 0.0417 48 0.0976 0.0417 49 0.0975 0.0412 50 0.0929 0.0407 51 0.0925 0.0400 52 0.0923 0.0399 53 0.0918 0.0395 54 0.0910 0.0375 55 0.0903 0.0373 56 0.0851 0.0368 57 0.0843 0.0357 58 0.0839 0.0356 59 0.0820 0.0354 60 0.0770 0.0326 61 0.0723 0.0303 ___________________________________________________________________ Stream Protection Duration POC #1 The Facility PASSED The Facility PASSED. Flow(cfs) Predev Mit Percentage Pass/Fail 0.0608 2438 943 38 Pass 0.0626 2231 854 38 Pass 0.0644 2033 789 38 Pass 0.0661 1871 719 38 Pass 0.0679 1698 664 39 Pass 0.0697 1575 622 39 Pass 0.0715 1435 572 39 Pass 0.0733 1315 526 40 Pass 0.0751 1199 487 40 Pass 0.0768 1092 446 40 Pass 0.0786 1011 410 40 Pass 0.0804 935 379 40 Pass 0.0822 850 346 40 Pass 0.0840 779 308 39 Pass 0.0858 703 280 39 Pass 0.0876 659 254 38 Pass 0.0893 612 233 38 Pass 0.0911 566 211 37 Pass 0.0929 515 189 36 Pass 0.0947 471 168 35 Pass 0.0965 433 151 34 Pass 0.0983 389 133 34 Pass 0.1001 367 121 32 Pass 0.1018 331 111 33 Pass 0.1036 304 100 32 Pass 0.1054 280 95 33 Pass 0.1072 257 91 35 Pass 0.1090 240 84 35 Pass 0.1108 221 80 36 Pass 0.1126 207 76 36 Pass 0.1143 196 75 38 Pass 0.1161 182 74 40 Pass 0.1179 166 72 43 Pass 0.1197 157 71 45 Pass 0.1215 148 69 46 Pass 0.1233 142 69 48 Pass 0.1250 132 68 51 Pass 0.1268 123 68 55 Pass 0.1286 114 65 57 Pass 0.1304 109 65 59 Pass 0.1322 102 64 62 Pass 0.1340 99 63 63 Pass 0.1358 92 63 68 Pass 0.1375 89 60 67 Pass 0.1393 84 59 70 Pass 0.1411 76 56 73 Pass 0.1429 72 55 76 Pass 0.1447 70 53 75 Pass 0.1465 66 51 77 Pass 0.1483 60 49 81 Pass 0.1500 53 47 88 Pass 0.1518 49 42 85 Pass 0.1536 43 40 93 Pass 0.1554 43 37 86 Pass 0.1572 40 37 92 Pass 0.1590 38 37 97 Pass 0.1608 34 35 102 Pass 0.1625 31 34 109 Pass 0.1643 30 32 106 Pass 0.1661 27 29 107 Pass 0.1679 27 28 103 Pass 0.1697 25 27 108 Pass 0.1715 24 24 100 Pass 0.1733 22 22 100 Pass 0.1750 21 21 100 Pass 0.1768 20 17 85 Pass 0.1786 19 16 84 Pass 0.1804 19 16 84 Pass 0.1822 18 13 72 Pass 0.1840 17 13 76 Pass 0.1857 15 11 73 Pass 0.1875 15 8 53 Pass 0.1893 15 6 40 Pass 0.1911 15 4 26 Pass 0.1929 13 4 30 Pass 0.1947 13 4 30 Pass 0.1965 11 4 36 Pass 0.1982 8 4 50 Pass 0.2000 8 4 50 Pass 0.2018 7 4 57 Pass 0.2036 6 2 33 Pass 0.2054 6 2 33 Pass 0.2072 5 2 40 Pass 0.2090 5 2 40 Pass 0.2107 5 2 40 Pass 0.2125 5 2 40 Pass 0.2143 4 2 50 Pass 0.2161 4 2 50 Pass 0.2179 3 2 66 Pass 0.2197 3 2 66 Pass 0.2215 3 2 66 Pass 0.2232 3 2 66 Pass 0.2250 3 2 66 Pass 0.2268 2 2 100 Pass 0.2286 2 2 100 Pass 0.2304 2 2 100 Pass 0.2322 2 2 100 Pass 0.2339 2 1 50 Pass 0.2357 2 0 0 Pass 0.2375 1 0 0 Pass _____________________________________________________ ___________________________________________________________________ Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0.0696 acre-feet On-line facility target flow: 0.038 cfs. Adjusted for 15 min: 0.038 cfs. Off-line facility target flow: 0.023 cfs. Adjusted for 15 min: 0.023 cfs. ___________________________________________________________________ LID Report LID Technique Used for Total Volume Volume Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volume Volume Volume Water Quality Treatment Facility (ac-ft.) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Detention Vault POC N 119.53 N 0.00 Total Volume Infiltrated 119.53 0.00 0.00 0.00 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Failed ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2024; All Rights Reserved. LOT 1LOT 2LOT 3LOT 4050100NCivil Engineering & Planning14900 Interurban Ave. S,Suite 279, Seattle, WA 98168Phone : 206.674.4659LARSEN DEVELOPMENTAREA EXHIBIT - PREDEVELOPEDLARSEN DEVELOPMENTMODELED VAULT TRIBUTARY (2000 aerial PER KC iMAP) LOT 2LOT 404080NCivil Engineering & Planning14900 Interurban Ave. S,Suite 279, Seattle, WA 98168Phone : 206.674.4659LARSEN DEVELOPMENTFRONTAGE TRIBUTARY EXHIBITLARSEN DEVELOPMENT LOT 1LOT 2LOT 3LOT 4050100NCivil Engineering & Planning14900 Interurban Ave. S,Suite 279, Seattle, WA 98168Phone : 206.674.4659LARSEN DEVELOPMENTAREA EXHIBIT - DEVELOPED CONDITIONLARSEN DEVELOPMENTMODELED VAULT TRIBUTARY