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9339_Cruz_Storm Drainage Report_8-18-21 Larson & Associates surveyors, engineers and planners 9027 Pacific Ave. Suite 4 Tacoma, WA 98444 STORM DRAINAGE REPORT PROPONENT: CRUZ DEVELOPMENTS, LLC 9935 COCHRANE AVE YELM, WA 98597 CONTACT: RYAN CRUZ PHONE: (253) 318-5494 PREPARED BY: Larson & Associates surveyors, engineers and planners 9027 Pacific Ave. Suite 4 Tacoma, WA 98444 (253) 474-3404 January 29, 2021 Revised August 18, 2021 PROJECT ENGINEER'S CERTIFICATION.......................................................................................................... 1 STORM DRAINAGE REPORT CHAPTER 1 - PROJECT DESCRIPTION ...................................................................................................................... 2 CHAPTER 2 - EXISTING CONDITION SUMMARY ................................................................................................... 2-3 CHAPTER 3 - OFF-SITE ANALYSIS .......................................................................................................................... 3 CHAPTER 4 - PERMANENT STORMWATER CONTROL PLAN .................................................................................. 4-7 SECTION 1 - PRE-DEVELOPED SITE HYDROLOGY ............................................................................................ 4 SECTION 2 - DEVELOPED SITE HYDROLOGY ................................................................................................... 4 SECTION 3 - PERFORMANCE STANDARDS AND GOALS .................................................................................... 4 SECTION 4 - FLOW CONTROL SYSTEM ......................................................................................................... 4-6 SECTION 5 - WATER QUALITY SYSTEM ........................................................................................................6-7 SECTION 6 - CONVEYANCE SYSTEM ANALYSIS AND DESIGN .......................................................................... 7 CHAPTER 5 - DISCUSSION OF MINIMUM REQUIREMENTS .................................................................................... 7-8 CHAPTER 6 - SPECIAL REPORTS AND STUDIES ......................................................................................................... 8 CHAPTER 7 - OTHER PERMITS .................................................................................................................................. 8 CHAPTER 8 - OPERATION AND MAINTENANCE MANUAL ......................................................................................... 8 CHAPTER 9 - BOND QUANTITIES WORKSHEET ........................................................................................................ 8 APPENDICES APPENDIX A - PROJECT MAPS ............................................................................................................................. A-1 APPENDIX B - SOUTH SOUND GEOTECHNICAL CONSULTING GEOTECHNICAL REPORT, DATED 2-20-20.……….B-1 APPENDIX C - BASIN MAP, LAND USE AREA SPREADSHEET, MGS FLOOD OUTPUTS…………………….…….C-1 APPENDIX D - BIOSWALE CALCULATIONS, PIPE MGS FLOOD OUTPUT & MANNING'S EQUATION FOR PIPE .. …D-1 I hereby state that this Storm Drainage Report for the CRUZ DEVELOPMENT project has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community for professional engineers. I understand that the City of Yelm does not and will not assume liability for the sufficiency, suitability, or performance of storm drainage facilities prepared by me. Grant J. Middleton, P.E. 1 CHAPTER 1 – PROJECT DESCRIPTIOIN The proposed Cruz Development project is located in the SE 1/4 of the NW 1/4 of Section 29, Township 17 North, Range 2 East of the Willamette Meridian in Yelm, Washington. The address is 17041 State Route (SR) 507, Yelm, WA 98597, and the parcel number is 64303200300. A vicinity map, parcel map and aerial of the project parcels are provided in Appendix A. The project consists of developing 5.82 acres of the 9.33-acre parcel into an automotive dealership with the balance of the property dedicated to Washington State Dept. of Transportation (WSDOT) for SR 507 right-of-way and to the City of Yelm and WSDOT for future right-of-way. An existing single- family residence at the northwest corner of the parcel will be converted to a temporary office. Property development will include a 12,000 square foot metal building, paved asphalt parking, driveways, display area, and vehicle storage, and the required stormwater facilities, water and sewer utilities, and emergency vehicle access for the proposed development. A Notice of Decision for site plan approval with conditions was issued by the City on April 22, 2021. For regulating stormwater runoff, the City of Yelm has adopted the latest version of the Washington State Dept. of Ecology’s Stormwater Management Manual for Western Washington (SWMMWW) dated July 2019 and as amended by the city. In accordance with Section 3.3, Volume I of the SWMMWW, this project must comply with all 9 Minimum Requirements for stormwater management as more than 5,000 S.F. of new impervious surface will be created by this project. Stormwater runoff generated from pervious and impervious surface areas of the proposed building, parking/driveway and outdoor display will be collected and conveyed to a biofiltration swale/infiltration pond and bioretention cells for water quality treatment and flow control. All disturbed pervious areas will receive compost amended topsoil in accordance with BMP T5.13, Chapter V-11, Volume V of the SWMMWW. CHAPTER 2 – EXISTING CONDITION SUMMARY The project parcel is located on the south side of SR 507 at the eastern edge of the City of Yelm’s city limits across from Wal-Mart; SR 507 borders the project site to the north. The property is currently zoned C-2 Heavy Commercial according to the City’s current Zoning Map. Surrounding properties consist of large tract farms to the south, west and east. The project property was previously an egg producing farm that has since been vacated; two long, vacant buildings remain from that previous use. An existing single-family residence exists at the project property’s northwest corner; the residence and associated driveway access will remain. The topography of the site is relatively flat with no more than 3 feet of elevation change; it appears the site slopes very gently downward from the southeast partially to the northwest but more predominately to the east toward the Nisqually River. The topographic high point of the project site is approximately 359.00 (NAVD 88) at the southeast corner with a low point situated on the west side of this site at approximately 356.00 feet. A topographic map and a copy of the FEMA Flood Insurance Rate Map for the project site are provided in Appendix A, and it does not appear the project site is in a 100-year flood plain. According to Thurston County GIS, approximately the easterly 40 feet lies within the High Groundwater Hazard Review Area. A geotechnical engineering study of the existing soil conditions was performed by South Sound Geotechnical Consulting (SSGC) on February 7, 2020; a copy of their geotechnical engineering 2 report dated February 20, 2020 is provided in Appendix B. SSGC observed, logged, and sampled 3 test pits ranging in depths from 6 feet to 9.5 feet below existing grade and performed one Pilot Infiltration Test (PIT). Under approximately 24 inches of topsoil, SSGC encountered native soils consisting of gravelly sand to sandy gravel with trace to some silt, cobbles and occasional boulder; the native soils were in a loose grading to a medium dense condition. SSGC identifies the primary geologic unit underlying the site and surrounding areas as Spanaway Gravelly Sandy Loam based on geologic mapping, and states that the native soils encountered are consistent with the mapped outwash soil. Groundwater was not observed in the test pits at the time of excavation, and SSGC noted that soil mottling or other indicators of shallow groundwater were not observed. SSGC installed piezometers in two of the test pits to monitor for the presence and depth of shallow groundwater. To determine soil infiltration rates, SSGC performed a small-scale PIT and a gradation analysis of soil samples taken from Test Pit #2. Using appropriate correction factors to the measured and calculated infiltration rates, SSGC recommends a long-term design infiltration rate of 17 inches per hour. SSGC forwarded soils samples to a laboratory to test for Cation Exchange Capacity (CEC) and organic content; the soils’ average CEC and organic content values were 7.25 milliequivalents and 2.29%, respectively. CHAPTER 3 – OFF-SITE ANALYSIS According to Thurston County GIS, the project property is located in the Nisqually watershed basin; the Nisqually River is located approximately 3,700 feet to the east. A site visit was conducted on February 10, 2020 during a period of moderate to heavy precipitation to observe existing runoff patterns and drainage conditions around the project property. At the time of the site visit, there was no evidence of stormwater runoff or run-on with the adjacent properties and SR 507 right-of-way, likely due to the flat topography and permeable glacial outwash soils. No evidenced of water ponding, erosion, or stormwater impacts to the property or adjacent properties were noted. No wetlands, erosion hazards, or landslide hazards were noted adjacent to the project property. There are no stormwater facilities within the SR 507 right-of-way, and it is likely that runoff from the roadway infiltrates into the adjacent shoulder areas, evidenced by the lack of ditches on the south side of the roadway. Although the property is not located in a flood plain, Thurston County GIS identifies the property’s easterly 40 feet is located in a High Groundwater Hazard Review Area (see GIS map in Appendix A). As noted in Chapter 2 above during SSGC’s geotechnical investigation, no ground water was observed in the soil test pits. During the 2019-2020 wet season, SSGC monitored the piezometers, and they found no evidence of groundwater to within 9.5 feet of the ground surface; their results are provided in Appendix B. According to Yelm Municipal Code (YMC) 18.21.080.G.3, “Performance Standards – General Requirements in High Ground Water Hazard Areas”, no development shall be located within 50 feet horizontally of the high ground water hazard area or 2 feet vertically above the base flood elevation, whichever is less. Based on the piezometer results by SSGC, the base flood elevation is at least 9.5 feet below the development’s ground elevation. Further, based on SSGC’s results, the proposed retention pond is the deepest infiltration stormwater facility, and the pond’s live-storage bottom will be more than 6 feet above the bottom of the recorded piezometers, therefore, the development also meets YMC 18.21.080.G.4. 3 CHAPTER 4 – PERMANENT STORMWATER CONTROL PLAN SECTION 1 – PRE-DEVELOPED SITE HYDROLOGY As mentioned previously, the project property used to be an egg producing farm; two long, vacant buildings remain from that previous use. An existing single-family residence exists at the project property’s northwest corner; the residence and associated driveway access will remain. Approximately 0.570 acres of the northern portion of the parcel will be dedicated to WSDOT for SR 507 right-of-way. That leaves 8.760 acres of the original 9.330 acres for project development. A pre-developed basin map of the 9.33-acre project property is provided in Appendix C. For stormwater modeling purposes, the entire project parcel, including the area to be dedicated to WSDOT as SR-507 right-of-way, was modeled as “Outwash Forest”. SECTION 2 – DEVELOPED SITE HYDROLOGY A breakdown of the developed areas within the project site is provided in the table below. Proposed Land Use Impervious and Pervious Coverage Proposed Land Use Impervious (acres) Pervious (acres) Total (acres) Commercial Building 0.286 0 0.286 Parking & Display Area 2.240 0.087 2.327 Future Vehicle Storage 1.873 0 1.873 Landscaping Buffers 0 0.516 0.516 Storm Pond & Bioswale 0.264 0.309 0.573 Ex. SFR /Temp. Office 0.223 0.022 0.245 Future WSDOT ROW 0.079 0.491 0.570 Future City & WSDOT 0 2.940 2.940 Total Area 4.965 4.365 9.330 A developed basin map and a more detailed breakdown of the impervious areas associated with each land use are provided in Appendix C. For the developed condition, 0.457 acres of the 0.570 acres to be dedicated to WSDOT as SR-507 right-of-way will remain unimproved, however, the area was included in the sizing of the proposed infiltration pond as equivalent area. For stormwater modeling, MGS Flood version 4.46 was used to determine pre-developed and developed peak flows at recurrence intervals from the 2-year through the 100-year, 24-hour storm events. SECTION 3 – PERFORMANCE STANDARDS AND GOALS For regulating stormwater runoff, the City of Yelm has adopted the latest version of the Washington State Dept. of Ecology’s Stormwater Management Manual for Western Washington (SWMMWW) dated July 2019 and as amended by the city. In accordance with Section 3.3, Volume I of the SWMMWW, this project must comply with all 9 Minimum Requirements for stormwater management as more than 5,000 S.F. of new impervious surface will be created by this project. See Chapter 5 below for additional information regarding how all 9 minimum requirements have been addressed. SECTION 4 – FLOW CONTROL SYSTEM Onsite flow control will be provided with the construction of an infiltration pond and bioretention cells. The infiltration pond is located in the west central portion of the property adjacent to the 4 west property line. The bioretention cells are located within the 8-foot perimeter landscape buffer, in the frontage landscape buffer, and within the parking lot landscape islands. The infiltration pond and bioretention cells will receive runoff from the project property as follows: Flow Control Facilities – Tributary Impervious and Pervious Areas Flow Control Facility Impervious (Acres) Pasture (Acres) Grass (Acres) Total (Acres) Infiltration Pond 3.240 0.309 2.739 6.288 Bioretention Cell #1 0.315 0.148 0.054 0.517 Bioretention Cell #2 0.078 0.056 0 0.134 Bioretention Cell #3 0.173 0.067 0 0.240 Bioretention Cell #4 0.172 0.039 0 0.211 Bioretention Cell #5 0.232 0.042 0 0.274 Bioretention Cell #6 0.094 0.025 0 0.119 Bioretention Cell #7 0.126 0.062 0 0.188 Bioretention Cell #8 0.301 0.105 0.188 0.594 Bioretention Cell #9 0 0.057 0.276 0.333 Bioretention Cell #10 0.234 0.057 0.140 0.431 Total Area 4.965 0.968 3.397 9.330 As mentioned in Section 2 above, 0.457 acres of future SR-507 right-of-way is included in the pervious area (i.e. – grass) tributary to the infiltration pond as equivalent area. A detailed breakdown of the impervious and pervious areas to each facility is provided in Appendix C. Infiltration Pond – Section V-5, Volume V of the SWMMWW (BMP T7.10) Design of the infiltration pond conforms to Section V-5, Volume V, of the SWMMWW. A stage storage volume table of the pond’s proposed configuration was input into MGS Flood; the MGS Flood output is provided in Appendix C. In the predeveloped condition, the 6.288-acre sub-basin was modeled as “Outwash Forest”. In the developed condition, 0.309 acres of pervious area were modeled as “Outwash Pasture” because of the proposed use of compost amended soils (BMP T5.13) as allowed under Section V-11.1, Volume V of the SWMMWW. The remaining 2.739 acres, including 0.457 acres of equivalent area for dedicated SR-507 right-of-way, were modeled as “Outwash Grass” because these areas will remain undeveloped. An infiltration rate of 8.50 inches/hour which is half the long-term rate calculated by SSGC was used to provide an additional safety factor. The bottom of the pond is at Elev. 352.70 and the top of the pond is at Elev. 356.50 which allows for live storage between Elev. 353.20 and Elev. 355.50 with 0.5 feet of sediment storage and 1 foot of freeboard. The water surface elevation equivalent to the 100-year, 24-hour storm event occurs at Elev. 353.43. Interior pond side slopes will be 2H:1V; the pond bottom and side slopes will be hydroseeded using a seed mixture from Table V-12.3, Stormwater Tract “Log Grow” Seed Mix, Volume V, of the SWMMWW. The entire pond will be fenced with 6-foot-high chain link fence and a gate at the south end. Emergency overflow will be accommodated via a 6- foot-wide spillway located on the pond’s west side. The spillway elevation will be 0.5 feet below the pond top at Elev. 356.00. A gravel access ramp, 15-feet wide, will be provided to the bottom of the pond constructed at a maximum 12% slope using a 2” thick layer of crushed rock over 2” – 4” quarry spalls over a geotextile fabric placed over the native subgrade. Signage similar to Figure V-12.12, Volume V, of the SWMMWW will be provided inside the fence on the pond’s north side. 5 Bioretention Cells –Section V-5, Volume V of the SWMMWW (BMP T7.30) Design of the bioretention cells conforms to Section V-5, Volume V, of the SWMMWW. MGS Flood was used for continuous modeling of the bioretention cells to determine the required length and bottom width of each cell. In the predeveloped condition, all sub-basins were modeled as “Outwash Forest”. In the developed condition, the pervious areas were modeled as “Outwash Pasture” because of the proposed use of compost amended soils (BMP T5.13) as allowed under Section V-5.3.1, Volume V of the SWMMWW except for those tributary areas that will remain undeveloped were modeled as “Outwash Grass”. All bioretention cells were designed using the default bioretention soil mix (BSM) described in Section V-7.4. For the BSM infiltration rate, a safety factor of 4 was applied to the default infiltration rate of 12 inches/hour for those cells whose contributing sub-basin area exceeded 5,000 square feet of pollution-generating impervious area, 10,000 square feet of total impervious area, or 3/4-acre of lawn and landscape. Otherwise, a safety factor of 2 was applied if none of the aforementioned thresholds were exceeded. Therefore, the BSM infiltration rates used were either 3 inches/hour or 6 inches/hour. A long-term infiltration rate of 8.5 inches/hour was used for the native soils which is half the design rate provided by SSGC as an additional safety factor. The results of the MGS Flood continuous modeling analyses for each bioretention cell are included in Appendix C, and the calculated minimum bioretention cell dimensions are provided on the accompanying site development plans. Design of the typical bioretention swale section follows Figure V-5.12 in Volume V of the SWMMWW. Cell bottom will be minimum 1 foot wide with a ponding depth of 1 foot and 0.5 feet of freeboard. Side slopes will be 2H:1V. The BSM will be 18 inches thick. Where sheet flow runoff enters the bioretention cells, 0.5 feet of woodchip mulch, aggregate, or sod will be provided between the edge of pavement and the top of the bioretention cells to provide energy dissipation and improve sheet flow dispersion across the cell. An overflow standpipe with the rim set 0.5 feet below the top of each cell will route overflow under the cell directly to the native subgrade which has a substantially higher infiltration rate. Minimum Requirement #7 An analysis using MGS Flood was performed to verify the entire 9.33 project property meets Minimum Requirement #7, Flow Control. In MGS Flood, under the predeveloped scenario, the entire 9.33 acres was modeled as “Outwash Forest”. In the developed scenario, the program sub- basins were set up the same as the infiltration pond and bioretention cell analyses. The infiltration pond, and bioretention cells were then linked to a separate point of compliance labeled “Minimum Requirement #7”. Running the model simulation, the project was found to meet Minimum Requirement #7 which also implies the project meets Minimum Requirement #5, On-Site Stormwater Management. A copy of the modeling results is provided in Appendix C. SECTION 5 – WATER QUALITY SYSTEM For those developed impervious and pervious areas tributary to the bioretention cells, Minimum Requirement #6 has been satisfied. For the 3.240 acres of impervious area and 3.048 acres of pervious area tributary to the infiltration pond, only 2.701 acres will be pollution generating impervious surface (PGIS); the remaining 0.539 acres of impervious area represents the area of the infiltration pond and the building roof area whose runoff will be routed directly to the pond via a 6-inch tightline. Reviewing the MGS Flood output for the retention pond design, a water quality discharge rate of 0.47 cfs was determined for the on-line condition and 0.26 cfs for the off-line 6 condition. For the 2.701 acres of PGIS, an on-line biofiltration swale is proposed to provide water quality treatment. Biofiltration Swale – BMP T9.10, Section V-7, Volume V of the SWMMWW Design of the biofiltration swale (bioswale) conforms to Section V-7, Volume V, of the SWMMWW. Since the bioswale will receive runoff from the PGIS upstream of the infiltration pond, the on-line water quality rate of 0.47 cfs was used to size the bioswale. Design calculations for sizing the bioswale, including a stability check at the 100-year discharge rate, is provided in Appendix D. The bioswale has a bottom width of 5 feet, a bottom length of 307 feet, a longitudinal slope of 1% and 4H:1V side slopes. A 6-inch Schedule 40 PVC perforated underdrain pipe will be installed under the bioswale because the bioswale slope is less than 1.5%; both the bioswale and underdrain will outlet into a catch basin with a beehive grate connected to the storm pipe collecting building roof runoff and conveying the discharge to the pond. At the inlet end, a rip rap pad of 2” – 4” quarry spalls will act to dissipate energy and spread the runoff flow across the bioswale width. SECTION 6 – CONVEYANCE SYSTEM ANALYSIS AND DESIGN Runoff generated from the pervious and impervious areas of the proposed development will sheet flow to the bioretention cells, bioswale and infiltration pond; the only piped conveyance is the storm pipe from the building roof drain tightline to the bioswale outlet catch basin and from the catch basin to the infiltration pond. Using MGS Flood, the 100-year, 24-hour storm peak flow from the building roof was determined to be 0.277 cfs. Using Manning’s equation with a Manning’s “n” of 0.013, a 6-inch pipe at 0.50% has a full-depth discharge capacity of 0.40 cfs. Therefore, the 6-inch drain pipe at 0.50% from the building to the infiltration pond will be adequate. Between the catch basin and pond, MGS Flood calculated the 100-year, 24-hour storm peak flow tributary to the pond to be 3.27 cfs. Again, using Manning’s equation with a Manning’s “n” of 0.013, 1 15-inch pipe at 0.30% has a full-depth discharge capacity of 3.54 cfs. Calculations for both pipes are provided in Appendix D. CHAPTER 5 – DISCUSSION OF MINIMUM REQUIREMENTS a.Minimum Requirement #1: Preparation of Stormwater Site Plan This report and the associated site development plan set fulfill this requirement. b.Minimum Requirement #2: Construction SWPPP The SWPPP that accompanies this report fulfills this requirement. c.Minimum Requirement #3: Source Control of Pollution Information on Source Control BMP’s is included in the Operation and Maintenance Manual (Minimum Requirement #9). d.Minimum Requirement #4: Preservation of Natural Drainage Systems and Outfalls As described in Chapters 2 and 3 above, onsite runoff does not appear to drain offsite but rather infiltrates through the highly permeable native soil. The lack of existing drainage outfalls from or through the site supports this condition. e.Minimum Requirement #5: On-Site Stormwater Management 7 According to Table 1-3.1, Volume 1, of the SWMMWW, for new development projects on any parcel inside the Urban Growth Area (UGA), compliance with this minimum requirement must include both the Low Impact Development Performance Standard (LIDPS) and BMP T5.13: Post-Construction Soil Quality and Depth or List #2. The use of LID BMPs such as the bioretention cells and infiltration pond allow the project to meet the LIDPS. Compost amended soils conforming to BMP T5.13 will be used in all landscaped areas. f.Minimum Requirement #6: Runoff Treatment See Chapter 4, Section 5 for additional information. g.Minimum Requirement #7: Flow Control See Chapter 4, Section 4 for additional information. h.Minimum Requirement #8: Wetland Protection To the best of our knowledge, there are no wetlands in or around the vicinity of our site. i. Minimum Requirement #9: Operation and Maintenance The accompanying Operation and Maintenance Manual fulfills this requirement. CHAPTER 6 – SPECIAL REPORT AND STUDIES A geotechnical report prepared by South Sound Geotechnical Consulting is included in Appendix B. CHAPTER 7 – OTHER PERMITS The following permits will be required in addition to the site development permit: •Coverage under Dept. of Ecology’s General Construction Stormwater Permit •City of Yelm and/or WSDOT Right-of-Way permits for work in SR 507 CHAPTER 8 – OPERATION AND MAINTENANCE MANUAL A completed Operation and Maintenance Manual accompanies this report. CHAPTER 9 – BOND QUANTITIES WORKSHEET If required, a construction cost estimate for work in SR 507 will be provided to the city for bonding prior to issuance of the right-of-way permit. End of Report 8 APPENDIX “A” PROJECT MAPS A-1 The information included on this map has been compiled by Thurston County staff from a variety of sources and is subject to change without notice. Additional elements may be present in reality that are not represented on the map. Ortho-photos and other data may not align. The boundaries depicted by these datasets are approximate. This document is not intended for use as a survey product. ALL DATA IS EXPRESSLY PROVIDED ‘AS IS’ AND ‘WITH ALL FAULTS’. Thurston County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. In no event shall Thurston County be liable for direct, indirect, incidental, consequential, special, or tort damages of any kind, including, but not limited to, lost revenues or lost profits, real or anticipated, resulting from the use, misuse or reliance of the information contained on this map. If any portion of this map or disclaimer is missing or altered, Thurston County removes itself from all responsibility from the map and the data contained within. The burden for determining fitness for use lies entirely with the user and the user is solely responsible for understanding the accuracy limitation of the information contained in this map. Authorized for 3rd Party reproduction for personal use only. Cruz Development - Vicinity Map 21,476Scale 1: 0 2/20/2020 Note: Legend 1000 2000 Feet Published: Map Created Using GeoData Public Website Label - Parcel Number Parcel Boundaries Roads - Major (Large Scale) <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads (Large Scale) Railroads County Border Olympia Municipal Airport Water Bodies (River - Small Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads Railroads County Border Olympia Municipal Airport Water Bodies (River - Small Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major Major Roads Ramp I 5; US 101 Roads (Large Scale) Railroads County Border 2020© Thurston County A-2 The information included on this map has been compiled by Thurston County staff from a variety of sources and is subject to change without notice. Additional elements may be present in reality that are not represented on the map. Ortho-photos and other data may not align. The boundaries depicted by these datasets are approximate. This document is not intended for use as a survey product. ALL DATA IS EXPRESSLY PROVIDED ‘AS IS’ AND ‘WITH ALL FAULTS’. Thurston County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. In no event shall Thurston County be liable for direct, indirect, incidental, consequential, special, or tort damages of any kind, including, but not limited to, lost revenues or lost profits, real or anticipated, resulting from the use, misuse or reliance of the information contained on this map. If any portion of this map or disclaimer is missing or altered, Thurston County removes itself from all responsibility from the map and the data contained within. The burden for determining fitness for use lies entirely with the user and the user is solely responsible for understanding the accuracy limitation of the information contained in this map. Authorized for 3rd Party reproduction for personal use only. Cruz Development - Parcel Map 9,028Scale 1: 0 2/20/2020 Note: Legend 400 800 Feet Published: Map Created Using GeoData Public Website Label - Parcel Number Parcel Boundaries Roads - Major (Large Scale) <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads (Large Scale) Railroads County Border Olympia Municipal Airport Water Bodies (River - Small Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads Railroads County Border Olympia Municipal Airport Water Bodies (River - Small Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major Major Roads Ramp I 5; US 101 Roads (Large Scale) Railroads County Border 2020© Thurston County A-3 The information included on this map has been compiled by Thurston County staff from a variety of sources and is subject to change without notice. Additional elements may be present in reality that are not represented on the map. Ortho-photos and other data may not align. The boundaries depicted by these datasets are approximate. This document is not intended for use as a survey product. ALL DATA IS EXPRESSLY PROVIDED ‘AS IS’ AND ‘WITH ALL FAULTS’. Thurston County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. In no event shall Thurston County be liable for direct, indirect, incidental, consequential, special, or tort damages of any kind, including, but not limited to, lost revenues or lost profits, real or anticipated, resulting from the use, misuse or reliance of the information contained on this map. If any portion of this map or disclaimer is missing or altered, Thurston County removes itself from all responsibility from the map and the data contained within. The burden for determining fitness for use lies entirely with the user and the user is solely responsible for understanding the accuracy limitation of the information contained in this map. Authorized for 3rd Party reproduction for personal use only. Cruz Development - Aerial Map 9,028Scale 1: 0 2/20/2020 Note: Legend 400 800 Feet Published: Map Created Using GeoData Public Website Parcel Boundaries Roads - Major Major Roads Ramp I 5; US 101 Roads (Large Scale) Railroads County Border 2020© Thurston County A-4 Cruz Development - Topographic Map 4,514 2/20/2020 Note: Legend Map Created Using GeoData Public Website The information included on this map has been compiled by Thurston County staff from a variety of sources and is subject to change without notice. Additional elements may be present in reality that are not represented on the map. Ortho-photos and other data may not align. The boundaries depicted by these datasets are approximate. This document is not intended for use as a survey product. ALL DATA IS EXPRESSLY PROVIDED ‘AS IS’ AND ‘WITH ALL FAULTS’. Thurston County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. In no event shall Thurston County be liable for direct, indirect, incidental, consequential, special, or tort damages of any kind, including, but not limited to, lost revenues or lost profits, real or anticipated, resulting from the use, misuse or reliance of the information contained on this map. If any portion of this map or disclaimer is missing or altered, Thurston County removes itself from all responsibility from the map and the data contained within. The burden for determining fitness for use lies entirely with the user and the user is solely responsible for understanding the accuracy limitation of the information contained in this map. Authorized for 3rd Party reproduction for personal use only. Scale 1: Published: Feet 2000 400 Contours 2ft 1996 (NGVD 29) Parcel Boundaries Roads - Major (Large Scale) <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads (Large Scale) Railroads County Border Olympia Municipal Airport Water Bodies (River - Large Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major <all other values> I 5 ACCESS; US 101 ACCESS; US 101 SB OFF RAMP I 5; US 101 Roads Railroads County Border Olympia Municipal Airport Water Bodies (River - Large Scale) Water Bodies (Other) Parks Cities Capital Forest County Background Roads - Major Major Roads Ramp I 5; US 101 Roads (Large Scale) Railroads County Border 2020© Thurston County A-5 USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250Feet Ü122°35'6.23"W 46°56'11.39"N 122°34'28.77"W46°55'46.82"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mile Zone X Future Conditions 1% AnnualChance Flood Hazard Zone XArea with Reduced Flood Risk due toLevee. See Notes.Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm SewerLevee, Dike, or Floodwall Cross Sections with 1% Annual Chance17.5 Water Surface ElevationCoastal Transect Coastal Transect BaselineProfile BaselineHydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of StudyJurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 2/20/2020 at 4:56:22 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following mapelements do not appear: basemap imagery, flood zone labels,legend, scale bar, map creation date, community identifiers,FIRM panel number, and FIRM effective date. Map images forunmapped and unmodernized areas cannot be used forregulatory purposes. Legend OTHER AREAS OFFLOOD HAZARD OTHER AREAS GENERALSTRUCTURES OTHERFEATURES MAP PANELS 8 1:6,000 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. A-6 The information included on this map has been compiled by Thurston County staff from a variety of sources and is subject to change without notice. Additional elements may be present in reality that are not represented on the map. Ortho-photos and other data may not align. The boundaries depicted by these datasets are approximate. This document is not intended for use as a survey product. ALL DATA IS EXPRESSLY PROVIDED ‘AS IS’ AND ‘WITH ALL FAULTS’. Thurston County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. In no event shall Thurston County be liable for direct, indirect, incidental, consequential, special, or tort damages of any kind, including, but not limited to, lost revenues or lost profits, real or anticipated, resulting from the use, misuse or reliance of the information contained on this map. If any portion of this map or disclaimer is missing or altered, Thurston County removes itself from all responsibility from the map and the data contained within. The burden for determining fitness for use lies entirely with the user and the user is solely responsible for understanding the accuracy limitation of the information contained in this map. Authorized for 3rd Party reproduction for personal use only. Cruz - High Groundwater Hazard Area 8,112Scale 1: 0 6/15/2021 Note: Legend 350 700 Feet Published: Map Created Using GeoData Public Website Address Points Contours 2ft 1996 (NGVD 29) Groundwater Concern Areas Low Concern Limited Groundwater Very Limited Groundwater Chloride > .5 mg/l Pesticide Application Groundwater Sensitive Areas ELD INLET WQPD HENDERSON INLET WQPD LAKES MCALLISTER SPRING; MCALLISTER SPRINGS High Groundwater Hazard Areas High Groundwater Hazard Area Salmon Creek High Groundwater Hazard High Groundwater Hazard Review Areas High Groundwater Review Area Salmon Creek High Groundwater Review Area Label - Parcel Number Parcel Boundaries Roads - Major (Large Scale) <all other values> 2021© Thurston County A-7 APPENDIX “B” SOUTH SOUND GEOTECHNICAL CONSULTING GEOTECHNICAL REPORT DATED 02-20-20 & GROUNDWATER MONITORING REPORT DATED 07-13-21 B-1 South Sound Geotechnical Consulting P.O. Box 39500, Lakewood, WA 98496 (253) 973-0515 February 20, 2020 Cruz Developments, LLC 33419 SR 507 S Roy, WA 98580 Attention: Mr. Ryan Cruz Subject: Geotechnical Engineering Report 17041 Hwy 507 Yelm, Washington SSGC Project No. 20005 Mr. Cruz, South Sound Geotechnical Consulting (SSGC) has completed a geotechnical assessment for the motor sports development planned at the above addressed property. Our services have been completed in general conformance with our proposal P20006 (dated January 17, 2020) and authorized per signature of our agreement for services. Our scope of services included a field evaluation consisting of three test pits and one infiltration test, laboratory testing, engineering analyses, and preparation of this report. PROJECT INFORMATION A new motor sport complex is planned on the approximate 9.3 (+/-) acre site on the south side of State Highway 507. Development plans include a new building with a footprint of about 12,000 square feet, asphalt paved access from Hwy 507, and new asphalt or gravel parking areas. We anticipate conventional spread footing foundations will be used for support of the building, with concrete slab-on-grade floors. Infiltration facilities are proposed to assist in control of stormwater. SURFACE CONDITIONS The site is rectangular in shape with the long axis trending north-south. An existing residence is in the general northwest portion. Two abandoned metal buildings are on the eastern and western sides. Most of the property is covered with field grass or lawn. We understand historic uses of the site include poultry production. Surface grades across the site are generally level. Overall elevation change is estimated at about 3 to 4 feet. SUBSURFACE CONDITIONS Subsurface conditions were characterized by completing three test pits and one infiltration test on February 7, 2020. Explorations were advanced to depths between 6 and 9.5 feet below existing ground surface. Approximate locations of the explorations are shown on Figure 1, Exploration Plan. A summary B-2 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 2 description of observed subgrade conditions is provided below. Logs of the test pits are provided in Appendix A. Soil Conditions Topsoil was below the surface in the excavations and extended to an average depth of about 2 feet. Native soil below the topsoil consisted gravelly sand to sandy gravel with trace to some silt, and cobbles and occasional boulder. These soils were in a loose grading to medium dense condition and continued to the termination depth of the test pits. They are considered to represent glacial outwash. Groundwater Conditions Groundwater was not observed in the test pits at the time of excavation. Mottling or other indicators of shallow groundwater was not observed to the base of the tests pits. The permanent groundwater level is anticipated to be at depth and should not adversely impact the planned expansion. Piezometers were installed in two of the test pits to monitor for the presence of shallow seasonal groundwater. Geologic Setting The USDA Soil Conservation Service Soil Map of Thurston County, Washington maps soils on the property as “Spanaway gravelly sandy loam”. Spanaway soils reportedly formed in glacial outwash. Native soils in the explorations appear to conform to the mapped outwash soil. GEOTECHNICAL DESIGN CONSIDERATIONS Planned development is considered feasible based on observed soil conditions in the test pits. Native outwash soils are considered suitable for support of foundations and pavements. Infiltration to support stormwater control is feasible. Groundwater was not observed to a depth of 9.5 feet below existing surface grade. We estimate the typical seasonal high groundwater levels will be at depth that should not adversely impact the planned expansion. Recommendations presented in the following sections should be considered general and may require modifications when earthwork and grading occur. They are based upon the subsurface conditions observed in the explorations and the assumption that finish site grades will be similar to existing grades. It should be noted subsurface conditions across the site may vary from those depicted on the exploration logs and can change with time. Therefore, proper site preparation will depend upon the weather and soil conditions encountered at the time of construction. We recommend SSGC review final plans and assess subgrade conditions at the time of construction. B-3 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 3 General Site Preparation Site grading and earthwork should include procedures to control surface water runoff. Grading the site without adequate drainage control measures may negatively impact site soils, resulting in increased export of impacted soil and import of fill materials, thereby potentially increasing the cost of the earthwork and subgrade preparation phases of the project. Site grading should include removal (stripping) of topsoil and any fill encountered in building and pavement areas. Subgrades should consist of firm native soils following stripping. Fill or topsoil thickness averaged about 2 feet in the test pits, but may be deeper in other locations. Final stripping depths can only be determined at the time of earthwork. General Subgrade Preparation Subgrades in building and pavement areas should consist of firm native outwash soils. We recommend exposed subgrades in building and conventional pavement areas are proofrolled using a large roller, loaded dump truck, or other mechanical equipment to assess subgrade conditions following stripping. Proofrolling efforts should result in the upper 1 foot of subgrade soils achieving a compaction level of at least 95 percent of the maximum dry density (MDD) per the ASTM D1557 test method. Wet, loose, or soft subgrades that cannot achieve this compaction level should be removed (over-excavated) and replaced with structural fill. The depth of over-excavation should be based on soil conditions at the time of construction. A representative of SSGC should be present to assess subgrade conditions during proofrolling. Grading and Drainage Positive drainage should be provided during construction and maintained throughout the life of the development. Surface water should not be allowed into cut/fill areas, building footprints, or pavement areas. Structural Fill Materials The suitability of soil for use as structural fill will depend on the gradation and moisture content of the soil when it is placed. Soils with higher fines content (soil fraction passing the U.S. No. 200 sieve) will become sensitive with higher moisture content. It is often difficult to achieve adequate compaction if soil moisture is outside of optimum ranges for soils that contain more than about 5 percent fines. Site Soils: Topsoil is not considered suitable for structural fill due to organic. It can be used in non-structural fill or landscape areas. Native outwash is considered suitable for structural fill, if properly moisture conditioned. However, the outwash contained variable cobbles and boulders. Particles larger than about 4 inches should be screened from outwash soils prior to their use as B-4 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 4 structural fill. Larger particles have a tendency to cluster during earthwork activities and can form voids and non-uniform compaction. Import Fill Materials: We recommend import structural fill placed during dry weather periods consist of material which meets the specifications for Gravel Borrow as described in Section 9- 03.14(1) of the 2018 Washington State Department of Transportation (WSDOT) Specifications for Road, Bridge, and Municipal Construction (Publication M 41-10). Gravel Borrow should be protected from disturbance if exposed to wet conditions after placement. During wet weather, or for backfill on wet subgrades, import soil suitable for compaction in wetter conditions should be provided. Imported fill for use in wet conditions should generally conform to specifications for Select Borrow as described in Section 9-03.14(2), or Crushed Surfacing per Section 9-03.9(3) of the 2018 WSDOT M-41 manual, with the modification that a maximum of 5 percent by weight shall pass the U.S. No. 200 sieve for these soil types. Structural fill placement and compaction is weather-dependent. Delays due to inclement weather are common, even when using select granular fill. We recommend site grading and earthwork be scheduled for the drier months of the year. Structural fill should not consist of frozen material. Structural Fill Placement We recommend structural fill is placed in lifts not exceeding about 10 inches in loose measure. It may be necessary to adjust lift thickness based on site and fill conditions during placement and compaction. Finer grained soil used as structural fill and/or lighter weight compaction equipment may require significantly thinner lifts to attain required compaction levels. Coarser granular soil with lower fines contents could potentially be placed in thicker lifts if they can be adequately compacted. Structural fill should be compacted to attain the recommended levels presented in Table 1, Compaction Criteria. Table 1. Compaction Criteria Fill Application Compaction Criteria* Footing areas (below structures and retaining walls) 95 % Upper 2 feet in pavement areas, slabs and sidewalks, and utility trenches 95 % Below 2 feet in pavement areas, slabs and sidewalks, and utility trenches 92 % Utility trenches or general fill in non-paved or -building areas 90 % *Per the ASTM D 1557 test method. Trench backfill within about 2 feet of utility lines should not be over-compacted to reduce the risk of damage to the line. In some instances the top of the utility line may be within 2 feet of the surface. Backfill in these circumstances should be compacted to a firm and unyielding condition. B-5 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 5 We recommend fill procedures include maintaining grades that promote drainage and do not allow ponding of water within the fill area. The contractor should protect compacted fill subgrades from disturbance during wet weather. In the event of rain during structural fill placement, the exposed fill surface should be allowed to dry prior to placement of additional fill. Alternatively, the wet soil can be removed. We recommend consideration is given to protecting haul routes and other high traffic areas with free-draining granular fill material (i.e. sand and gravel containing less than 5 percent fines) or quarry spalls to reduce the potential for disturbance to the subgrade during inclement weather. Earthwork Procedures Conventional earthmoving equipment should be suitable for earthwork at this site. Earthwork may be difficult during periods of wet weather or if elevated soil moisture is present. Excavated site soils may not be suitable as structural fill depending on the soil moisture content and weather conditions at the time of earthwork. If soils are stockpiled and wet weather is anticipated, the stockpile should be protected with securely anchored plastic sheeting. If stockpiled soils become unusable, it may become necessary to import clean, granular soils to complete wet weather site work. Wet or disturbed subgrade soils should be over-excavated to expose firm, non-yielding, non-organic soils and backfilled with compacted structural fill. We recommend the earthwork portion of this project be completed during extended periods of dry weather. If earthwork is completed during the wet season (typically late October through May) it may be necessary to take extra measures to protect subgrade soils. If earthwork takes place during freezing conditions, we recommend the exposed subgrade be allowed to thaw and be re-compacted prior to placing subsequent lifts of structural fill. Alternatively, the frozen soil can be removed to unfrozen soil and replaced with structural fill. The contractor is responsible for designing and constructing stable, temporary excavations (such as utility trenches) to maintain stability of excavation sides and bottoms. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. Temporary excavation cuts should be sloped at inclinations of 1.5H:1V (Horizontal:Vertical) or flatter, unless the contractor can demonstrate the safety of steeper inclinations. Deeper excavations may require shoring. Permanent cut and fill slopes should be graded at inclinations of 2H:1V, or flatter. A geotechnical engineer and accredited testing material laboratory should be retained during the construction phase of the project to observe earthwork operations and to perform necessary tests and observations during subgrade preparation, placement and compaction of structural fill, and backfilling of excavations. B-6 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 6 Foundations Foundations can be placed on native outwash soils or on a zone of structural fill above prepared native subgrades as described in this report. The following recommendations are for conventional spread footing foundations: Bearing Capacity (net allowable): 3,000 pounds per square foot (psf) for footings supported firm native outwash subgrades prepared as described in this report. Footing Width (Minimum): 18 inches (Strip) 24 inches (Column) Embedment Depth (Minimum): 18 inches (Exterior) 12 inches (Interior) Settlement: Total: < 1 inch Differential: < 1/2 inch (over 30 feet) Allowable Lateral Passive Resistance: 325 psf/ft* (below 18 inches) Allowable Coefficient of Friction: 0.40* *These values include a factor of safety of approximately 1.5. The net allowable bearing pressures presented above may be increased by one-third to resist transient, dynamic loads such as wind or seismic forces. Lateral resistance to footings should be ignored in the upper 12-inches from exterior finish grade. Foundation Construction Considerations All foundation subgrades should be free of water and loose soil prior to placing concrete, and should be prepared as recommended in this report. Concrete should be placed soon after excavating and compaction to reduce disturbance to bearing soils. Should soils at foundation level become excessively dry, disturbed, saturated, or frozen, the affected soil should be removed prior to placing concrete. We recommend SSGC observe all foundation subgrades prior to placement of concrete. Foundation Drainage Ground surface adjacent foundations should be sloped away from buildings. We recommend footing drains are installed around perimeter footings placed on structural fill. Footing drains are not considered necessary for footings founded directly on native outwash soils. Footing drains should include a minimum 4-inch diameter perforated rigid plastic or metal drain line installed at the base of the footing. The perforated drain lines should be connected to a tight line pipe B-7 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 7 that discharges to an approved storm drain receptor. The drain line should be surrounded by a zone of clean, free-draining granular material having less than 5 percent passing the No. 200 sieve or meeting the requirements of section 9-03.12(2) “Gravel Backfill for Walls” in the 2018 WSDOT (M41-10) manual. The free-draining aggregate zone should be at least 12 inches wide and wrapped in filter fabric. The granular fill should extend to within 6 inches of final grade where it should be capped with compacted fill containing sufficient fines to reduce infiltration of surface water into the footing drains. Alternately, the ground surface can be paved with asphalt or concrete. Cleanouts are recommended for maintenance of the drain system. On-Grade Floor Slabs On-grade floor slabs should be placed on native soils or structural fill prepared as described in this report. We recommend a modulus subgrade reaction of 200 pounds per square inch per inch (psi/in) for native soil or compacted granular structural fill over native soil. We recommend a capillary break is provided between the prepared subgrade and bottom of slab. Capillary break material should be a minimum of 4 inches thick and consist of compacted clean, free- draining, well graded course sand and gravel. The capillary break material should contain less than 5 percent fines, based on that soil fraction passing the U.S. No. 4 sieve. Alternatively, a clean angular gravel such as No. 7 aggregate per Section 9-03.1(4) C of the 2018 WSDOT (M41-10) manual could be used for this purpose. We recommend positive separations and/or isolation joints are provided between slabs and foundations, and columns or utility lines to allow independent movement where needed. Backfill in interior trenches beneath slabs should be compacted in accordance with recommendations presented in this report. A vapor retarder should be considered beneath concrete slabs that will be covered with moisture sensitive or impervious coverings (such as tile, wood, etc.), or when the slab will support equipment or stored materials sensitive to moisture. We recommend the slab designer refer to ACI 302 and/or ACI 360 for procedures and limitations regarding the use and placement of vapor retarders. Seismic Considerations Seismic parameters and values in Table 3 are recommended based on the 2015 International Building Code (IBC). B-8 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 8 Table 3. Seismic Parameters PARAMETER VALUE 2015 International Building Code (IBC) Site Classification1 D Ss Spectral Acceleration for a Short Period 1.242 S1 Spectral Acceleration for a 1-Second Period 0.493g Fa Site Coefficient for a Short Period 1.003 Fv Site Coefficient for a 1-Second Period 1.507 1 Note: In general accordance with the 2015 International Building Code, Section 1613.3.2 for risk categories I,II,III. IBC Site Class is based on the estimated characteristics of the upper 100 feet of the subsurface profile. Ss, S1, Fa, and Fv values based on the OSHPD Seismic Design Maps website using referenced site latitude and longitude. Liquefaction Soil liquefaction is a condition where loose, typically granular soils located below the groundwater surface lose strength during ground shaking, and is often associated with earthquakes. The risk of liquefaction at this site is low for the design level earthquake based on the Thurston County Liquefaction Hazard Map, dated April 2011. A site-specific liquefaction analyses was not part of our scope and would be required to fully assess liquefaction potential and impacts. Infiltration Characteristics Infiltration facilities are planned to support control of stormwater. An assessment of infiltration potential of native outwash was completed per Volume 3, Appendix III-A, Method 1 of the 2016 Thurston County Drainage Design and Erosion Control Manual. One small-scale pilot infiltration test was completed in the proposed storm pond area on the west side of the site. Additionally, a gradation correlation based on Massmann’s equation (Method 2 of the County Manual) was completed on a sample of the native outwash from test pit TP-2. Results of the tests are presented in Table 4. Table 4. Infiltration Rates Test Location and Depth Soil Type Field or Calculated Infiltration Rate (in/hr) Corrected Infiltration Rate (in/hr) Correction Factors* (Fg/Ft/Fp) TP-2, S-1, 6 feet Outwash 74 26 (1/0.4/0.9) PIT-1, 6 feet Outwash 37 17 (1/0.5/0.9) *Correction Factors from the 2016 Thurston County Drainage Design and Erosion Control Manual. B-9 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 9 Field and calculated infiltration rates are considered appropriate for the soil tested and are similar to infiltration tests completed at other sites with similar (Spanaway) soil throughout Thurston County. Slightly more silt was observed in the soil at the PIT site (as shown in gradation test results presented in Appendix B) and resulted in lower infiltration rates. We recommend a long-term design rate of 17 inches per hour (in/hr) for design of infiltration facilities located in outwash soils to account for natural variability in these soils. Modifications to the above correction factors (or other factors) should be applied to the above recommended long-term rate, as required by the County manual for the type of infiltration system used. Groundwater was not observed in the test pits to a maximum depth of 9.5 feet. Mottling or other indicators of elevated groundwater were not observed. Infiltration facilities should not be adversely influenced by groundwater or other impervious soil layers. Cation Exchange Capacity (CEC) and organic content tests were completed on two random samples of the site soils near the estimated depth of proposed infiltration trenches. Test results are summarized in the table below. Table 5. CEC and Organic Content Results Test Site, Sample Number, Depth CEC Results (milliequivalents) CEC Required* (milliequivalents) Organic Content Results (%) Organic Content Required* (%) PIT-1, S-1, 6 ft 9.3 ≥ 5 2.78 ≥1.0 TP-2, S-1, 6 ft 5.2 1.80 *Values from the 2016 Thurston County Drainage Design and Erosion Control Manual. Organic content and CEC results of the samples satisfy County requirements. Conventional Pavement Sections Subgrades for conventional pavements should be prepared as described in the “Subgrade Preparation” and “Structural Fill” sections of this report. Subgrades below pavement sections should be graded or crowned to promote drainage and not allow for ponding of water beneath the section. If drainage is not provided and ponding occurs, subgrade soils could become saturated, lose strength, and result in premature distress or failure of the section. In addition, the pavement surfacing should also be graded to promote drainage and reduce the potential for ponding of water on the pavement surface. Minimum recommended pavement sections for conventional asphalt pavements in the development are presented in Table 6. Pavement sections within the Hwy 507 right-of-way should conform to Washington State Department of Transportation requirements. B-10 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 10 Table 6. Pavement Sections Traffic Area Minimum Recommended Pavement Section Thickness (inches) Asphalt Concrete Surface1 Aggregate Base Course2 Subbase Aggregate3 Car Parking 2 4 6 Interior Truck Access Routes 3 6 8 1 1/2 –inch nominal aggregate hot-mix asphalt per WSDOT 9-03.8(1) 2 Crushed Surfacing Base Course per WSDOT 9-03.9(3) 3 Native 95% compacted soil or imported sand and gravel . Conventional Pavement Maintenance The performance and lifespan of pavements can be significantly impacted by future maintenance. The above pavement sections represent minimum recommended thicknesses and, as such, periodic maintenance should be completed. Proper maintenance will slow the rate of pavement deterioration, and will improve pavement performance and life. Preventive maintenance consists of both localized maintenance (crack and joint sealing and patching) and global maintenance (surface sealing). Added maintenance measures and reduced pavement life should be anticipated over the lifetime of pavements if any existing fill or topsoil is left in-place beneath pavement sections. REPORT CONDITIONS This report has been prepared for the exclusive use of Cruz Developments, LLC and their agents for specific application to the project discussed, and has been prepared in accordance with generally accepted geotechnical engineering practices in the area. No warranties, either express or implied, are intended or made. The analysis and recommendations presented in this report are based on observed soil conditions and test results at the indicated locations, and from other geologic information discussed. This report does not reflect variations that may occur across the site, or due to the modifying effects of construction, or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. This report was prepared for the planned type of development of the site as discussed herein. It is not valid for third party entities or alternate types of development on the site without the express written consent of SSGC. If development plans change we should be notified to review those changes and modify our recommendations as necessary. B-11 B-12 N South Sound Geotechnical Consulting P.O. Box 39500 Lakewood, WA 98496 (253) 973-0515 Figure 1 – Exploration Plan Cruz Development – Hwy507 Yelm, WA SSGC Project #20005 Approximate Test Pit Location PIT - 1 TP - 1 PIT - 1 Approximate Infiltration Test Location Scale: NTS Base map from drawing titled “Site Plan” provided by Larson and Associates TP-1 Legend TP-2 TP-3 PIT-1 TP-1 B-13 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 Appendix A Field Exploration Procedures and Exploration Logs B-14 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 A-1 Field Exploration Procedures Our field exploration for this project included three test pits and one infiltration test completed on February 7, 2020. The approximate locations of the explorations are shown on Figure 1, Exploration Plan. Exploration locations were determined by pacing from site features. Ground surface elevations referenced on the logs were inferred from topographic information from Google Earth. Exploration locations and elevations should be considered accurate only to the degree implied by the means and methods used. A private excavation contractor subcontracted to SSGU dug the test pits and infiltration test hole. Soil samples were collected and stored in moisture tight containers for further assessment and laboratory testing. Explorations were backfilled with excavated soils and tamped when completed. Please note backfill in the explorations may settle with time. Backfill material located in roads or building areas should be re-excavated and recompacted, or replaced with structural fill. The following logs indicate the observed lithology of soils and other materials observed in the explorations at the time of excavation. Where a soil contact was observed to be gradational, our log indicates the average contact depth. Our logs also indicate the approximate depth to groundwater (where observed at the time of excavation), along with sample numbers and approximate sample depths. Soil descriptions on the logs are based on the Unified Soil Classification System. B-15 Project: Cruz Development SSGC Job # 20005 TEST PIT LOGS PAGE 1 OF 2 Location: Yelm, WA TEST PIT LOGS FIGURE A-1 South Sound Geotechnical Consulting PIT-1, TP-1 TO TP-3 Logged by: THR PIT-1 Depth (feet) Material Description 0 – 2 2 – 6 Topsoil: Silt, sand, gravel, with organics: Loose, moist, dark brown. Sandy GRAVEL/Gravelly SAND with trace to some silt and occasional cobble and boulder: Loose to medium dense, moist, golden brown. (Glacial Outwash)(Sample S-1 @ 6 feet) Test hole completed at approximately 6 feet on 2/7/20. Groundwater not observed at time of excavation. Approximate surface elevation: 176 feet Test Pit TP-1 Depth (feet) Material Description 0 – 2 2 – 9 Topsoil Sandy GRAVEL/Gravelly SAND with trace to some silt and occasional cobble and boulder: Loose to medium dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 6 feet on 2/7/20 due to caving. Groundwater not observed at time of excavation. Piezometer installed at 9 feet. Approximate surface elevation: 172 feet Test Pit TP-2 Depth (feet) Material Description 0 – 2 2 – 9.5 Topsoil. Sandy GRAVEL/Gravelly SAND with trace to some silt and occasional cobble and boulder: Loose to medium dense, moist, golden brown. (Glacial Outwash)(Sample S-1 @ 6 feet) Test pit completed at approximately 9.5 feet on 2/7/20 due to caving. Groundwater not observed at time of excavation. Piezometer installed at 9.5 feet Approximate surface elevation: 174 feet B-16 Project: Cruz Development SSGC Job # 20005 TEST PIT LOGS PAGE 2 OF 2 Location: Yelm, WA TEST PIT LOGS FIGURE A-1 South Sound Geotechnical Consulting PIT-1, TP-1 TO TP-3 Logged by: THR Test Pit TP-3 Depth (feet) Material Description 0 – 2 2 – 5 Topsoil Sandy GRAVEL/Gravelly SAND with trace to some silt and occasional cobble and boulder: Loose to medium dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 5 feet on 2/7/20. Groundwater not observed at time of excavation. Approximate surface elevation: 175 feet B-17 Geotechnical Engineering Report SSGC Lakeview Apartment Expansion Olympia, Washington SSGC Project No. 19111 February 12, 2020 Appendix B Laboratory Testing and Results B-18 Geotechnical Engineering Report SSGC Cruz Development – Hwy 507 Yelm, Washington SSGC Project No. 20005 February 20, 2020 B-1 Laboratory Testing Select soil samples were tested for organic content and cation exchange capacity (CEC) by Northwest Agricultural Consultants of Kennewick, Washington. Grain size (gradation) tests were completed by Construction Testing Laboratories (CTL) of Puyallup, Washington. Results of the laboratory testing are included in this appendix. B-19 Report shall not be reproduced except in full without the written approval of the Laboratory. Report pertains only to the material tested.Tested By: R Rowden Checked By: C Pedersen Particle Size Distribution Report ASTM C-117,C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0 30 20 10 22 10 86 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO) Material Description Atterberg Limits Classification Remarks Source of Sample: PIT-1 Sample Number: 20-254 Date: Client: Project: Project No:Figure Grab Sample, S-1 Sampled at 6'2" 1" 3/4" 1/2" 3/8" #4 #8 #16 #30 #50 #100 #200 100 78 70 62 58 50 42 34 23 14 10 7.8 Report: #02 Sampled by: Client South Sound Geotechnical Cruz (20005) 8311 PL=LL=PI= USCS=AASHTO= *(no specification provided) 02-07-20 Construction Testing Laboratories 400 Valley Ave. NE, Suite #102 Puyallup WA, 98372 Tel. (253) 383-8778 B-20 Report shall not be reproduced except in full without the written approval of the Laboratory. Report pertains only to the material tested.Tested By: R Rowden Checked By: C Pedersen Particle Size Distribution Report ASTM C-117,C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0 20 34 11 23 10 26 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO) Material Description Atterberg Limits Classification Remarks Source of Sample: TP-2 Sample Number: 20-253 Date: Client: Project: Project No:Figure Grab Sample, S-1 Sampled at 6'2" 1" 3/4" 1/2" 3/8" #4 #8 #16 #30 #50 #100 #200 100 82 80 70 63 46 36 28 18 7 4 2.5 GP Report: #01 Sampled by: Client South Sound Geotechnical Cruz (20005) 8311 PL=LL=PI= USCS=AASHTO= *(no specification provided) 02-07-20 Construction Testing Laboratories 400 Valley Ave. NE, Suite #102 Puyallup WA, 98372 Tel. (253) 383-8778 B-21 2545 W Falls Avenue Kennewick, WA 99336 509.783.7450 www.nwag.com lab@nwag.com Sample ID Organic Matter Cation Exchange Capacity PIT-1, S-1 @ 6.0’ 2.78% 9.3 meq/100g TP-2, S-1 @ 6.0’ 1.80% 5.2 meq/100g Method ASTM D2974 EPA 9081 South Sound Geotechnical Consulting PO Box 39500 Lakewood, WA 98496 Report: 50398-1-1 Date: February 11, 2020 Project No: 20003 Project Name: Cruz B-22 UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification Group Symbol Group NameB Coarse Grained Soils More than 50% retained on No. 200 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels Less than 5% finesC Cu  4 and 1  Cc  3E GW Well-graded gravelF Cu  4 and/or 1  Cc  3E GP Poorly graded gravelF Gravels with Fines More than 12% finesC Fines classify as ML or MH GM Silty gravelF,G, H Fines classify as CL or CH GC Clayey gravelF,G,H Sands 50% or more of coarse fraction passes No. 4 sieve Clean Sands Less than 5% finesD Cu  6 and 1  Cc  3E SW Well-graded sandI Cu  6 and/or 1  Cc  3E SP Poorly graded sandI Sands with Fines More than 12% finesD Fines classify as ML or MH SM Silty sandG,H,I Fines Classify as CL or CH SC Clayey sandG,H,I Fine-Grained Soils 50% or more passes the No. 200 sieve Silts and Clays Liquid limit less than 50 inorganic PI  7 and plots on or above “A” lineJ CL Lean clayK,L,M PI  4 or plots below “A” lineJ ML SiltK,L,M organic Liquid limit - oven dried 0.75 OL Organic clayK,L,M,N Liquid limit - not dried Organic siltK,L,M,O Silts and ClaysLiquid limit 50 or more inorganic PI plots on or above “A” line CH Fat clayK,L,M PI plots below “A” line MH Elastic SiltK,L,M organic Liquid limit - oven dried 0.75 OH Organic clayK,L,M,P Liquid limit - not dried Organic siltK,L,M,Q Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW -GM well-graded gravel with silt, GW -GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW -SM well-graded sand with silt, SW -SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = 6010 2 30 DxD )(D F If soil contains  15% sand, add “with sand” to group name. GIf fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. HIf fines are organic, add “with organic fines” to group name. I If soil contains  15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains  30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains  30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI  4 and plots on or above “A” line. O PI  4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. B-23 South Sound Geotechnical Consulting P.O. Box 39500, Lakewood, WA 98496 (253) 973-0515 July 13, 2021 Cruz Developments, LLC 33419 SR 507 S Roy, WA 98580 Attention: Mr. Ryan Cruz Subject: Groundwater Monitoring (Winter 2020) 17041 Hwy 507 Yelm, Washington SSGC Project No. 20005 Mr. Cruz, South Sound Geotechnical Consulting (SSGC) has completed monitoring of groundwater levels through the 2020 winter season at the Motor Sport Complex at the above addressed property in Yelm, Washington. Piezometers were installed in two test pits on the property on February 7, 2020 as part of our geotechnical evaluation of the site (report dated February 20, 2020). Approximate locations of the test pits with piezometers (TP-1 and TP-2) are shown on Figure 1, Exploration Plan. Groundwater levels measured from the original date of the test pits to early April 2020 are presented in the table below. Test Pit Date Groundwater Level (Below Surface) TP-1 2/7/20 dry 3/8/20 dry 4/7/20 dry TP-2 2/7/20 dry 3/8/20 dry 4/7/20 dry Groundwater was not observed in the piezometers during the 2020 winter season to the maximum depth of the piezometers (9.5 feet below existing grade). Groundwater monitoring of other sites throughout the Puget Sound area indicated the month of February had the highest groundwater levels during the winter season (2020). Seasonal groundwater levels should not adversely affect the planned development at this site. REPORT CONDITIONS This report has been prepared for the exclusive use of Cruz Developments, LLC for specific application to the project discussed, and has been prepared in accordance with generally accepted geotechnical engineering practices in the area. No warranties, either express or implied, are intended or made of future groundwater conditions. B-24 B-25 N South Sound Geotechnical Consulting P.O. Box 39500 Lakewood, WA 98496 (253) 973-0515 Figure 1 – Exploration Plan Cruz Development – Hwy507 Yelm, WA SSGC Project #20005 Approximate Test Pit Location PIT - 1 TP - 1 PIT - 1 Approximate Infiltration Test Location Scale: NTS Base map from drawing titled “Site Plan” provided by Larson and Associates TP-1 Legend TP-2 TP-3 PIT-1 TP-1 B-26 APPENDIX “C” BASIN MAP, LAND USE AREA SPREADSHEET, INFILTRATION POND, BIORETENTION CELLS & MINIMUM REQUIREMENT #7 MGS FLOOD OUTPUTS C-1 PRE-DEVELOPED BASIN = 9.330 AC EXISTING IMPERVIOUS = 0.092 AC EXISTING HOUSE TO REMAIN = 0.029 AC EXISTING DRIVEWAY TO REMAIN = 0.063 AC EXISTING PERVIOUS = 9.238 AC ENTIRE BASIN MODELED AS OUTWASH FOREST IN PRE-DEVELOPED CONDITION BIORETENTION CELL #1 = 0.517 AC IMPERVIOUS AREA = 0.315 AC ASPHALT = 0.307 AC SIDEWALK = 0.008 AC PERVIOUS AREA = 0.202 AC BIORETENTION CELL#2 = 0.134 AC IMPERVIOUS AREA = 0.078 AC ASPHALT = 0.071 AC SIDEWALK = 0.007 AC PERVIOUS AREA = 0.056 AC BIORETENTION CELL #3 = 0.240 AC IMPERVIOUS AREA = 0.173 AC PERVIOUS AREA = 0.067 AC BIORETENTION CELL #6 = 0.119 AC IMPERVIOUS AREA = 0.094 AC ASPHALT = 0.083 AC SIDEWALK = 0.011 AC PERVIOUS AREA = 0.025 AC BIORETENTION CELL #5 = 0.274 AC IMPERVIOUS AREA = 0.232 AC ASPHALT = 0.214 AC SIDEWALK = 0.018 AC PERVIOUS AREA = 0.042 AC BIORETENTION CELL #4 = 0.211 AC IMPERVIOUS AREA = 0.172 AC PERVIOUS AREA = 0.039 AC BIORETENTION CELL #7 = 0.188 AC IMPERVIOUS AREA = 0.126 AC PERVIOUS AREA = 0.062 AC BIORETENTION CELL #8 = 0.594 AC IMPERVIOUS AREA = 0.301 AC PERVIOUS AREA = 0.293 AC BIORETENTION CELL #9 = 0.333 AC PERVIOUS AREA = 0.333 AC INFILTRATION POND BASIN = 5.831 AC IMPERVIOUS AREA = 3.240 AC BLDG ROOF = 0.275 AC ASPHALT = 2.684 AC SIDEWALK = 0.017 AC POND = 0.263 AC PERVIOUS AREA = 2.591 AC BIORETENTION CELL #10 = 0.431 AC IMPERVIOUS AREA = 0.234 AC BLDG ROOF = 0.029 AC ASPHALT = 0.168 AC SIDEWALK = 0.009 AC GRAVEL DRIVE = 0.028 AC PERVIOUS AREA = 0.197 AC FUTURE WSDOT ROW = 0.570 AC EXISTING IMPERVIOUS = 0.045 AC EXISTING PERVIOUS = 0.525 AC C-2 Land Use Asphalt (SF)Walkway (SF)Other Imp. (SF)Roof (SF)Landscape (SF)Existing (SF)Total Area (SF)Total Area (AC) Commercial Building 465.0 12000.0 12465.0 0.286 Parking & Display Area 96366.0 1195.0 3796.0 101357.0 2.327 Future Vehicle Storage 81600.0 81600.0 1.873 Perim. Landscape Buffers 22462.0 22462.0 0.516 Storm Pond & Bioswale 11475.0 13469.0 24944.0 0.573 Exist. SFR / Temp Office 7313.0 1155.0 1250.0 960.0 10678.0 0.245 Future SR-507 ROW 1980.0 275.0 1200.0 1485.0 19905.0 24845.0 0.570 Future City & WSDOT ROW 128079.0 128079.0 2.940 Total Area (SF)187259.0 3090.0 12675.0 13250.0 42172.0 147984.0 406430.0 Total Area (AC)4.299 0.071 0.291 0.304 0.968 3.397 9.330 Total Impervious (SF)190349.0 216274.0 Total Impervious (AC)4.370 4.965 Total PGIS Total Impervious Infiltration Facility Asphalt (SF)Walkway (SF)Other Imp. (SF)Roof (SF)Landscape (SF)Ex. Grass (SF)Total Area (SF)Total Area (AC) Bioretention Cell #1 13384.5 350.0 6446.0 2331.0 22511.5 0.517 Bioretention Cell #2 3078.0 305.0 2457.0 5840.0 0.134 Bioretention Cell #3 7548.0 2925.0 10473.0 0.240 Bioretention Cell #4 7488.0 1701.0 9189.0 0.211 Bioretention Cell #5 9333.5 770.0 1848.0 11951.5 0.274 Bioretention Cell #6 3600.0 510.0 1068.0 5178.0 0.119 Bioretention Cell #7 5500.0 2700.0 8200.0 0.188 Bioretention Cell #8 13100.0 4581.0 8200.0 25881.0 0.594 Bioretention Cell #9 2502.0 11990.0 14492.0 0.333 Bioretention Cell #10 7313.0 410.0 1200.0 1250.0 2475.0 6146.0 18794.0 0.431 Infiltration Pond 116914.0 745.0 11475.0 12000.0 13469.0 99412.0 254015.0 5.831 187259.0 3090.0 12675.0 13250.0 42172.0 128079.0 386525.0 8.873 SF AC Future SR-507->19905.0 0.457 Total Impervious to Infiltration Pond 141134.0 3.240 406430.0 9.330 Total Pervious to Infiltration Pond 132786.0 3.048 Total PGIS for Sizing WQ Facility to Pond 117659.0 2.701 Existing 19,905 SF to be dedicated as Future SR-507 ROW but will be undeveloped is included with sizing of Infiltration Pond as equivalent area Existing areas not developed, including future City & WSDOT ROW, modeled as "Outwash Grass" Gross parcel area = 9.330 acres (406,430 SF); future SR-507 ROW = 0.570 acres (24,845 SF); Net parcel area = 8.760 acres (381,585 SF) ASSUMPTIONS/CONDITIONS: Cruz Development Land Use Area Calculation Minimum landscape buffers: 8' perimeter, 4' streetscape, 24 SF/parking stall w/min. 100 SF per landscaped parking area Existing house & driveway access at NW corner of property to remain; house to be converted to temporary office with parking Assume all landscape buffers include bioretention swales for stormwater WQ treatment & Flow Control of adjacent impervious runoff Assume infiltration pond water surface area = 170' x 67.5' = 11,475 SF (0.263 AC)C-3 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/05/2021 9:15 AM Report Generation Date: 08/05/2021 9:16 AM ————————————————————————————————— Input File Name: 9339_Cruz_Retention Pond.fld Project Name: Cruz Development Analysis Title: Size Retention Pond Comments: Size retention pond for 3.240 AC of impervious & 2.591 AC of pervious plus 0.457 AC for future SR-507 ROW as ex. grass. ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 6.288 6.288 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 6.288 6.288 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 6.288 ---------------------------------------------- Subbasin Total 6.288 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-4 ---------- Subbasin : Developed ---------- -------Area (Acres) -------- Outwash Pasture 0.309 Outwash Grass 2.282 Impervious 3.240 ---------------------------------------------- Subbasin Total 5.831 ---------- Subbasin : SR-507 Undeveloped ---------- -------Area (Acres) -------- Outwash Grass 0.457 ---------------------------------------------- Subbasin Total 0.457 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Retention Pond Link Type: Structure Downstream Link: None User Specified Elevation Volume Table Used Elevation (ft) Pond Volume (cu-ft) 353.20 0. 353.50 4372. 354.00 8987. 354.50 13853. 355.00 18975. 355.50 24358. 356.00 30009. 356.50 36341. Constant Infiltration Option Used Infiltration Rate (in/hr): 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 24.00 Common Length (ft) : 0.000 Riser Crest Elevation : 355.50 ft C-5 Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Retention Pond ********** Link Inflow Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 1.225 5-Year 1.574 10-Year 1.843 25-Year 2.311 50-Year 2.868 100-Year 3.272 Discharge used for 15-inch pipe conveyance analysis 200-Year 3.394 ********** Link: Retention Pond ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 353.207 1.11-Year 353.207 1.25-Year 353.208 2.00-Year 353.210 3.33-Year 353.212 5-Year 353.213 10-Year 353.218 25-Year 353.247 50-Year 353.331 100-Year 353.439 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- C-6 Subbasin: Predeveloped 1668.728 _____________________________________ Total: 1668.728 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Developed 861.729 Subbasin: SR-507 Undeveloped 151.701 Link: Retention Pond 1454.849 _____________________________________ Total: 2468.278 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 10.562 ac-ft/year, Post Developed: 15.622 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Retention Pond ********** Basic Wet Pond Volume (91% Exceedance): 14392. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 21587. cu-ft 15-Minute Timestep, Water Quality Treatment Design DischargeOn-line Design Discharge Rate (91% Exceedance): 0.47 cfsUsed for Bioswale DesignOff-line Design Discharge Rate (91% Exceedance): 0.26 cfs Time to Infiltrate 91% Treatment Volume, (Hours): 2.25 Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 1454.85 Inflow Volume Including PPT-Evap (ac-ft): 1454.85 Total Runoff Infiltrated (ac-ft): 1454.85, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Retention Pond C-7 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 4.860E-03 2-Year 0.000 5-Year 5.017E-03 5-Year 0.000 10-Year 5.049E-03 10-Year 0.000 25-Year 5.181E-03 25-Year 0.000 50-Year 6.786E-03 50-Year 0.000 100-Year 1.081E-02 100-Year 0.000 200-Year 1.365E-02 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-8 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/04/2021 9:05 AM Report Generation Date: 08/04/2021 9:05 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #1.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #1 Design Comments: Design bioretention swale in frontage landscape buffer for 0.315 AC of impervious and 0.202 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.517 0.506 Area of Links that Include Precip/Evap (acres) 0.000 0.011 Total (acres) 0.517 0.517 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.517 ---------------------------------------------- Subbasin Total 0.517 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-9 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.315 ---------------------------------------------- Subbasin Total 0.315 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.137 Outwash Grass 0.054 ---------------------------------------------- Subbasin Total 0.191 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #1 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 240.0 Bottom Width (ft) : 2.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 480.Area at Riser Crest El (sq-ft) : 1,464. (acres) : 0.034 Volume at Riser Crest (cu-ft) : 1,113. (ac-ft) : 0.026 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-10 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.201 1.11-Year 100.243 1.25-Year 100.277 2.00-Year 100.383 3.33-Year 100.486 5-Year 100.543 10-Year 100.643 25-Year 100.789 50-Year 100.851 100-Year 100.956 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 137.203 _____________________________________ Total: 137.203 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 C-11 Subbasin: Pervious 64.133 Link: Bioretention Cell #1 146.413 _____________________________________ Total: 210.545 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.868 ac-ft/year, Post Developed: 1.333 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 141.32 Inflow Volume Including PPT-Evap (ac-ft): 146.41 Total Runoff Infiltrated (ac-ft): 146.41, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 3.996E-04 2-Year 0.000 5-Year 4.125E-04 5-Year 0.000 10-Year 4.151E-04 10-Year 0.000 25-Year 4.260E-04 25-Year 0.000 50-Year 5.579E-04 50-Year 0.000 100-Year 8.884E-04 100-Year 0.000 200-Year 1.123E-03 200-Year 1.267E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** C-12 Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -99.9% PASSMaximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -98.3% PASSMaximum Excursion from Q2 to Q50 (Must be less than 10%): -63.2% PASSPercent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -100.0%PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -99999.0%PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-13 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:23 AM Report Generation Date: 06/16/2021 11:23 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #2.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #2 Design Comments: Design bioretention swale in NE landscape buffer for 0.078 AC of impervious and 0.056 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.134 0.132 Area of Links that Include Precip/Evap (acres) 0.000 0.002 Total (acres) 0.134 0.134 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.134 ---------------------------------------------- Subbasin Total 0.134 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-14 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.078 ---------------------------------------------- Subbasin Total 0.078 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.054 ---------------------------------------------- Subbasin Total 0.054 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #2 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 29.0 Bottom Width (ft) : 3.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 87.Area at Riser Crest El (sq-ft) : 231.(acres) : 0.005 Volume at Riser Crest (cu-ft) : 182.(ac-ft) : 0.004 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-15 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #2 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.124 1.11-Year 100.158 1.25-Year 100.203 2.00-Year 100.331 3.33-Year 100.424 5-Year 100.493 10-Year 100.607 25-Year 100.789 50-Year 100.844 100-Year 100.968 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 35.561 _____________________________________ Total: 35.561 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 18.213 C-16 Link: Bioretention Cell #2 35.875 _____________________________________ Total: 54.088 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.225 ac-ft/year, Post Developed: 0.342 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #2 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 34.99 Inflow Volume Including PPT-Evap (ac-ft): 35.87 Total Runoff Infiltrated (ac-ft): 35.87, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #2 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.036E-04 2-Year 0.000 5-Year 1.069E-04 5-Year 0.000 10-Year 1.076E-04 10-Year 0.000 25-Year 1.104E-04 25-Year 0.000 50-Year 1.446E-04 50-Year 0.000 100-Year 2.303E-04 100-Year 0.000 200-Year 2.910E-04 200-Year 1.187E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -99.9% PASS C-17 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -99999.0% PASSMaximum Excursion from Q2 to Q50 (Must be less than 10%): -99999.0% PASSPercent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -100.0%PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -99999.0%PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-18 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:28 AM Report Generation Date: 06/16/2021 11:28 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #3.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #3 Design Comments: Design bioretention swale in landscape buffer east of parking area for 0.173 AC of impervious and 0.067 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.240 0.236 Area of Links that Include Precip/Evap (acres) 0.000 0.004 Total (acres) 0.240 0.240 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.240 ---------------------------------------------- Subbasin Total 0.240 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-19 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.173 ---------------------------------------------- Subbasin Total 0.173 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.063 ---------------------------------------------- Subbasin Total 0.063 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #3 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 183.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 183.Area at Riser Crest El (sq-ft) : 935.(acres) : 0.021 Volume at Riser Crest (cu-ft) : 611.(ac-ft) : 0.014 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-20 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #3 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.257 1.11-Year 100.296 1.25-Year 100.328 2.00-Year 100.422 3.33-Year 100.500 5-Year 100.553 10-Year 100.630 25-Year 100.752 50-Year 100.811 100-Year 100.865 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 63.692 _____________________________________ Total: 63.692 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 21.249 C-21 Link: Bioretention Cell #3 79.689 _____________________________________ Total: 100.938 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.403 ac-ft/year, Post Developed: 0.639 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #3 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 77.59 Inflow Volume Including PPT-Evap (ac-ft): 79.69 Total Runoff Infiltrated (ac-ft): 79.69, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #3 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.855E-04 2-Year 0.000 5-Year 1.915E-04 5-Year 0.000 10-Year 1.927E-04 10-Year 0.000 25-Year 1.978E-04 25-Year 0.000 50-Year 2.590E-04 50-Year 0.000 100-Year 4.124E-04 100-Year 0.000 200-Year 5.212E-04 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS C-22 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-23 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:31 AM Report Generation Date: 06/16/2021 11:31 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #4.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #4 Design Comments: Design bioretention swale in landscape buffer east of building for 0.172 AC of impervious and 0.039 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.211 0.207 Area of Links that Include Precip/Evap (acres) 0.000 0.004 Total (acres) 0.211 0.211 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.211 ---------------------------------------------- Subbasin Total 0.211 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-24 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.172 ---------------------------------------------- Subbasin Total 0.172 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.035 ---------------------------------------------- Subbasin Total 0.035 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #4 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 165.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 165.Area at Riser Crest El (sq-ft) : 845.(acres) : 0.019 Volume at Riser Crest (cu-ft) : 552.(ac-ft) : 0.013 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-25 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #4 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.292 1.11-Year 100.333 1.25-Year 100.367 2.00-Year 100.469 3.33-Year 100.558 5-Year 100.614 10-Year 100.693 25-Year 100.822 50-Year 100.877 100-Year 100.950 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 55.996 _____________________________________ Total: 55.996 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 11.805 C-26 Link: Bioretention Cell #4 79.066 _____________________________________ Total: 90.871 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.354 ac-ft/year, Post Developed: 0.575 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #4 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 77.13 Inflow Volume Including PPT-Evap (ac-ft): 79.07 Total Runoff Infiltrated (ac-ft): 79.07, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #4 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.631E-04 2-Year 0.000 5-Year 1.683E-04 5-Year 0.000 10-Year 1.694E-04 10-Year 0.000 25-Year 1.739E-04 25-Year 0.000 50-Year 2.277E-04 50-Year 0.000 100-Year 3.626E-04 100-Year 0.000 200-Year 4.582E-04 200-Year 6.324E-03 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -100.0% PASS C-27 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -99999.0% PASSMaximum Excursion from Q2 to Q50 (Must be less than 10%): -78.9% PASSPercent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -100.0%PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -99999.0%PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-28 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:37 AM Report Generation Date: 06/16/2021 11:37 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #5.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #5 Design Comments: Design bioretention swale in west parking landscape island for 0.232 AC of impervious and 0.042 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.274 0.263 Area of Links that Include Precip/Evap (acres) 0.000 0.011 Total (acres) 0.274 0.274 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.274 ---------------------------------------------- Subbasin Total 0.274 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-29 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.232 ---------------------------------------------- Subbasin Total 0.232 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.031 ---------------------------------------------- Subbasin Total 0.031 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #5 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 132.0 Bottom Width (ft) : 3.5 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 462.Area at Riser Crest El (sq-ft) : 1,020. (acres) : 0.023 Volume at Riser Crest (cu-ft) : 877.(ac-ft) : 0.020 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-30 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #5 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.129 1.11-Year 100.171 1.25-Year 100.200 2.00-Year 100.310 3.33-Year 100.410 5-Year 100.474 10-Year 100.600 25-Year 100.742 50-Year 100.824 100-Year 100.934 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 72.715 _____________________________________ Total: 72.715 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 10.456 C-31 Link: Bioretention Cell #5 108.822 _____________________________________ Total: 119.277 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.460 ac-ft/year, Post Developed: 0.755 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #5 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 104.03 Inflow Volume Including PPT-Evap (ac-ft): 108.82 Total Runoff Infiltrated (ac-ft): 108.82, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #5 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 2.118E-04 2-Year 0.000 5-Year 2.186E-04 5-Year 0.000 10-Year 2.200E-04 10-Year 0.000 25-Year 2.258E-04 25-Year 0.000 50-Year 2.957E-04 50-Year 0.000 100-Year 4.709E-04 100-Year 0.000 200-Year 5.950E-04 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS C-32 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-33 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:41 AM Report Generation Date: 06/16/2021 11:41 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #6.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #6 Design Comments: Design bioretention swale in east parking landscape island for 0.094 AC of impervious and 0.025 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.119 0.117 Area of Links that Include Precip/Evap (acres) 0.000 0.002 Total (acres) 0.119 0.119 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.119 ---------------------------------------------- Subbasin Total 0.119 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-34 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.094 ---------------------------------------------- Subbasin Total 0.094 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.023 ---------------------------------------------- Subbasin Total 0.023 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #6 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 96.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 96.Area at Riser Crest El (sq-ft) : 500.(acres) : 0.011 Volume at Riser Crest (cu-ft) : 324.(ac-ft) : 0.007 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-35 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #6 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.100 1.11-Year 100.122 1.25-Year 100.151 2.00-Year 100.227 3.33-Year 100.287 5-Year 100.326 10-Year 100.388 25-Year 100.454 50-Year 100.546 100-Year 100.659 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 31.581 _____________________________________ Total: 31.581 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 7.757 C-36 Link: Bioretention Cell #6 43.147 _____________________________________ Total: 50.904 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.200 ac-ft/year, Post Developed: 0.322 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #6 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 42.15 Inflow Volume Including PPT-Evap (ac-ft): 43.15 Total Runoff Infiltrated (ac-ft): 43.15, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #6 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 0.000 2-Year 0.000 5-Year 0.000 5-Year 0.000 10-Year 0.000 10-Year 0.000 25-Year 0.000 25-Year 0.000 50-Year 1.284E-04 50-Year 0.000 100-Year 2.045E-04 100-Year 0.000 200-Year 2.584E-04 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS C-37 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-38 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/04/2021 8:35 AM Report Generation Date: 08/04/2021 8:36 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #7.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #7 Design Comments: Design bioretention swale within SE perimeter landscape buffer for 0.126 AC of impervious and 0.062 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.188 0.181 Area of Links that Include Precip/Evap (acres) 0.000 0.007 Total (acres) 0.188 0.188 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.188 ---------------------------------------------- Subbasin Total 0.188 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-39 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.126 ---------------------------------------------- Subbasin Total 0.126 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.055 ---------------------------------------------- Subbasin Total 0.055 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #7 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 294.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 294.Area at Riser Crest El (sq-ft) : 1,490. (acres) : 0.034 Volume at Riser Crest (cu-ft) : 978.(ac-ft) : 0.022 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-40 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #7 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.057 1.11-Year 100.071 1.25-Year 100.089 2.00-Year 100.145 3.33-Year 100.184 5-Year 100.215 10-Year 100.263 25-Year 100.343 50-Year 100.370 100-Year 100.437 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 49.892 _____________________________________ Total: 49.892 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 Subbasin: Pervious 18.550 C-41 Link: Bioretention Cell #7 59.619 _____________________________________ Total: 78.170 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.316 ac-ft/year, Post Developed: 0.495 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #7 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 56.51 Inflow Volume Including PPT-Evap (ac-ft): 59.62 Total Runoff Infiltrated (ac-ft): 59.62, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #7 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.453E-04 2-Year 0.000 5-Year 1.500E-04 5-Year 0.000 10-Year 1.509E-04 10-Year 0.000 25-Year 1.549E-04 25-Year 0.000 50-Year 2.029E-04 50-Year 0.000 100-Year 3.231E-04 100-Year 0.000 200-Year 4.082E-04 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS C-42 Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-43 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/04/2021 8:46 AM Report Generation Date: 08/04/2021 8:46 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #8.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #8 Design Comments: Design bioretention swale within south perimeter landscape buffer for 0.301 AC of impervious and 0.293 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.594 0.583 Area of Links that Include Precip/Evap (acres) 0.000 0.011 Total (acres) 0.594 0.594 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.594 ---------------------------------------------- Subbasin Total 0.594 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-44 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.301 ---------------------------------------------- Subbasin Total 0.301 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.094 Outwash Grass 0.188 ---------------------------------------------- Subbasin Total 0.282 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #8 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 485.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 485.Area at Riser Crest El (sq-ft) : 2,445. (acres) : 0.056 Volume at Riser Crest (cu-ft) : 1,608. (ac-ft) : 0.037 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-45 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #8 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.132 1.11-Year 100.157 1.25-Year 100.179 2.00-Year 100.260 3.33-Year 100.316 5-Year 100.352 10-Year 100.401 25-Year 100.509 50-Year 100.597 100-Year 100.616 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 157.638 _____________________________________ Total: 157.638 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 C-46 Subbasin: Pervious 94.111 Link: Bioretention Cell #8 140.360 _____________________________________ Total: 234.471 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.998 ac-ft/year, Post Developed: 1.484 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #8 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 135.13 Inflow Volume Including PPT-Evap (ac-ft): 140.36 Total Runoff Infiltrated (ac-ft): 140.36, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #8 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 4.591E-04 2-Year 0.000 5-Year 4.739E-04 5-Year 0.000 10-Year 4.769E-04 10-Year 0.000 25-Year 4.894E-04 25-Year 0.000 50-Year 6.410E-04 50-Year 0.000 100-Year 1.021E-03 100-Year 0.000 200-Year 1.290E-03 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** C-47 Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-48 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/04/2021 8:52 AM Report Generation Date: 08/04/2021 8:52 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #9.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #9 Design Comments: Design bioretention swale within SW perimeter landscape buffer for 0.333 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.333 0.328 Area of Links that Include Precip/Evap (acres) 0.000 0.005 Total (acres) 0.333 0.333 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.333 ---------------------------------------------- Subbasin Total 0.333 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 C-49 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.053 Outwash Grass 0.275 ---------------------------------------------- Subbasin Total 0.328 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #9 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 212.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 212.Area at Riser Crest El (sq-ft) : 1,080. (acres) : 0.025 Volume at Riser Crest (cu-ft) : 707.(ac-ft) : 0.016 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft C-50 Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: Bioretention Cell #9 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.002 1.11-Year 100.003 1.25-Year 100.003 2.00-Year 100.004 3.33-Year 100.005 5-Year 100.006 10-Year 100.012 25-Year 100.035 50-Year 100.087 100-Year 100.309 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 88.373 _____________________________________ Total: 88.373 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Pervious 109.162 Link: Bioretention Cell #9 2.656 _____________________________________ Total: 111.818 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.559 ac-ft/year, Post Developed: 0.708 ac-ft/year C-51 ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #9 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 0.23 Inflow Volume Including PPT-Evap (ac-ft): 2.66 Total Runoff Infiltrated (ac-ft): 2.66, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #9 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 2.574E-04 2-Year 0.000 5-Year 2.657E-04 5-Year 0.000 10-Year 2.674E-04 10-Year 0.000 25-Year 2.744E-04 25-Year 0.000 50-Year 3.594E-04 50-Year 0.000 100-Year 5.722E-04 100-Year 0.000 200-Year 7.231E-04 200-Year 0.000 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 0.0% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-52 **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 0.0% PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-53 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 06/16/2021 11:59 AM Report Generation Date: 06/16/2021 11:59 AM ————————————————————————————————— Input File Name: 9339_Cruz_Bioretention Cell #10.fld Project Name: Cruz Development Analysis Title: Bioretention Cell #10 Design Comments: Design bioretention swale within perimeter landscape buffer north of pond for 0.234 AC of impervious and 0.197 AC of pervious ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.431 0.425 Area of Links that Include Precip/Evap (acres) 0.000 0.006 Total (acres) 0.431 0.431 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.431 ---------------------------------------------- Subbasin Total 0.431 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 C-54 ---------- Subbasin : Impervious ---------- -------Area (Acres) -------- Impervious 0.234 ---------------------------------------------- Subbasin Total 0.234 ---------- Subbasin : Pervious ---------- -------Area (Acres) -------- Outwash Pasture 0.051 Outwash Grass 0.140 ---------------------------------------------- Subbasin Total 0.191 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: Bioretention Cell #10 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 242.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 242.Area at Riser Crest El (sq-ft) : 1,230. (acres) : 0.028 Volume at Riser Crest (cu-ft) : 806.(ac-ft) : 0.019 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-55 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 1 ********** Link: Bioretention Cell #10 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.266 1.11-Year 100.304 1.25-Year 100.338 2.00-Year 100.433 3.33-Year 100.513 5-Year 100.577 10-Year 100.647 25-Year 100.772 50-Year 100.863 100-Year 100.938 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 114.380 _____________________________________ Total: 114.380 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Impervious 0.000 C-56 Subbasin: Pervious 63.674 Link: Bioretention Cell #1 107.832 _____________________________________ Total: 171.506 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.724 ac-ft/year, Post Developed: 1.085 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: Bioretention Cell #10 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 105.04 Inflow Volume Including PPT-Evap (ac-ft): 107.83 Total Runoff Infiltrated (ac-ft): 107.83, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Bioretention Cell #10 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 3.332E-04 2-Year 0.000 5-Year 3.439E-04 5-Year 0.000 10-Year 3.460E-04 10-Year 0.000 25-Year 3.551E-04 25-Year 0.000 50-Year 4.651E-04 50-Year 0.000 100-Year 7.407E-04 100-Year 0.000 200-Year 9.359E-04 200-Year 2.133E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** C-57 Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -99.9% PASSMaximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -97.6% PASSMaximum Excursion from Q2 to Q50 (Must be less than 10%): -47.4% PASSPercent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -100.0%PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -99999.0%PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- C-58 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 08/05/2021 8:18 AM Report Generation Date: 08/05/2021 8:27 AM ————————————————————————————————— Input File Name: 9339_Cruz_Min Reqmt #7.fld Project Name: Cruz Development Analysis Title: Minimum Requirement #7 Comments: Determine if project meets Minimum Requirement #7 ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 9.330 9.268 Area of Links that Include Precip/Evap (acres) 0.000 0.062 Total (acres) 9.330 9.330 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 9.330 ---------------------------------------------- Subbasin Total 9.330 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 12 C-59 ---------- Subbasin : Developed ---------- -------Area (Acres) -------- Outwash Pasture 0.309 Outwash Grass 2.282 Impervious 3.240 ---------------------------------------------- Subbasin Total 5.831 ---------- Subbasin : Developed Cell #1 ---------- -------Area (Acres) -------- Outwash Pasture 0.137 Outwash Grass 0.054 Impervious 0.315 ---------------------------------------------- Subbasin Total 0.506 ---------- Subbasin : Developed Cell #2 ---------- -------Area (Acres) -------- Outwash Pasture 0.054 Impervious 0.078 ---------------------------------------------- Subbasin Total 0.132 ---------- Subbasin : Developed Cell #3 ---------- -------Area (Acres) -------- Outwash Pasture 0.063 Impervious 0.173 ---------------------------------------------- Subbasin Total 0.236 ---------- Subbasin : Developed Cell #4 ---------- -------Area (Acres) -------- Outwash Pasture 0.035 Impervious 0.172 ---------------------------------------------- Subbasin Total 0.207 ---------- Subbasin : Developed Cell #5 ---------- -------Area (Acres) -------- Outwash Pasture 0.031 Impervious 0.232 ---------------------------------------------- Subbasin Total 0.263 ---------- Subbasin : Developed Cell #6 ---------- -------Area (Acres) -------- Outwash Pasture 0.023 Impervious 0.094 ---------------------------------------------- C-60 Subbasin Total 0.117 ---------- Subbasin : Developed Cell #7 ---------- -------Area (Acres) -------- Outwash Pasture 0.056 Impervious 0.126 ---------------------------------------------- Subbasin Total 0.182 ---------- Subbasin : Developed Cell #8 ---------- -------Area (Acres) -------- Outwash Pasture 0.094 Outwash Grass 0.188 Impervious 0.301 ---------------------------------------------- Subbasin Total 0.583 ---------- Subbasin : Developed Cell #9 ---------- -------Area (Acres) -------- Outwash Pasture 0.053 Outwash Grass 0.276 ---------------------------------------------- Subbasin Total 0.329 ---------- Subbasin : Developed Cell #10 ---------- -------Area (Acres) -------- Outwash Pasture 0.051 Outwash Grass 0.140 Impervious 0.234 ---------------------------------------------- Subbasin Total 0.425 ---------- Subbasin : SR-507 Undeveloped ---------- -------Area (Acres) -------- Outwash Grass 0.457 ---------------------------------------------- Subbasin Total 0.457 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 12 C-61 ------------------------------------------ Link Name: Retention Pond Link Type: Structure Downstream Link Name: Min. Reqmt. #7 User Specified Elevation Volume Table Used Elevation (ft) Pond Volume (cu-ft) 353.20 0. 353.50 4372. 354.00 8987. 354.50 13853. 355.00 18975. 355.50 24358. 356.00 30009. 356.50 36341. Constant Infiltration Option Used Infiltration Rate (in/hr): 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 24.00 Common Length (ft) : 0.000 Riser Crest Elevation : 355.50 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #1 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 240.0 Bottom Width (ft) : 2.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 480.Area at Riser Crest El (sq-ft) : 1,464. (acres) : 0.034 Volume at Riser Crest (cu-ft) : 1,113. (ac-ft) : 0.026 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 C-62 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Min. Reqmt. #7 Link Type: Copy Downstream Link: None ------------------------------------------ Link Name: Bioretention Cell #2 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 29.0 Bottom Width (ft) : 3.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 87.Area at Riser Crest El (sq-ft) : 231.(acres) : 0.005 Volume at Riser Crest (cu-ft) : 182.(ac-ft) : 0.004 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 C-63 ------------------------------------------ Link Name: Bioretention Cell #3 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 183.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 183.Area at Riser Crest El (sq-ft) : 935.(acres) : 0.021 Volume at Riser Crest (cu-ft) : 611.(ac-ft) : 0.014 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #4 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 165.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 165.Area at Riser Crest El (sq-ft) : 845.(acres) : 0.019 Volume at Riser Crest (cu-ft) : 552.(ac-ft) : 0.013 C-64 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #5 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 132.0 Bottom Width (ft) : 3.5 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 462.Area at Riser Crest El (sq-ft) : 1,020. (acres) : 0.023 Volume at Riser Crest (cu-ft) : 877.(ac-ft) : 0.020 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry C-65 Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #6 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 96.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 96.Area at Riser Crest El (sq-ft) : 500.(acres) : 0.011 Volume at Riser Crest (cu-ft) : 324.(ac-ft) : 0.007 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #7 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 294.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 294.Area at Riser Crest El (sq-ft) : 1,490. (acres) : 0.034 Volume at Riser Crest (cu-ft) : 978. C-66 (ac-ft) : 0.022 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #8 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 485.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 485.Area at Riser Crest El (sq-ft) : 2,445. (acres) : 0.056 Volume at Riser Crest (cu-ft) : 1,608. (ac-ft) : 0.037 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft C-67 Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #9 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.00 Storage Depth (ft) : 1.00 Bottom Length (ft) : 212.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 212.Area at Riser Crest El (sq-ft) : 1,080. (acres) : 0.025 Volume at Riser Crest (cu-ft) : 707.(ac-ft) : 0.016 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.00 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Bioretention Cell #10 Link Type: Bioretention Facility Downstream Link Name: Min. Reqmt. #7 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 103.00 Storage Depth (ft) : 3.00 Bottom Length (ft) : 242.0 Bottom Width (ft) : 1.0 Side Slopes (ft/ft) : L1= 2.00 L2= 2.00 W1= 2.00 W2= 2.00 Bottom Area (sq-ft) : 242.Area at Riser Crest El (sq-ft) : 3,302. C-68 (acres) : 0.076 Volume at Riser Crest (cu-ft) : 5,316. (ac-ft) : 0.122 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 3.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 8.50 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 103.00 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 12 Number of Links: 12 ********** Link: Retention Pond ********** Link Inflow Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 1.225 5-Year 1.574 10-Year 1.843 25-Year 2.311 50-Year 2.868 100-Year 3.272 200-Year 3.394 ********** Link: Retention Pond ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) C-69 ====================================== 1.05-Year 353.207 1.11-Year 353.207 1.25-Year 353.208 2.00-Year 353.210 3.33-Year 353.212 5-Year 353.213 10-Year 353.218 25-Year 353.247 50-Year 353.331 100-Year 353.439 ********** Link: Bioretention Cell #1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.201 1.11-Year 100.243 1.25-Year 100.277 2.00-Year 100.383 3.33-Year 100.486 5-Year 100.543 10-Year 100.643 25-Year 100.789 50-Year 100.851 100-Year 100.956 ********** Link: Bioretention Cell #2 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.124 1.11-Year 100.158 1.25-Year 100.203 2.00-Year 100.331 3.33-Year 100.424 5-Year 100.493 10-Year 100.607 25-Year 100.789 50-Year 100.844 100-Year 100.968 ********** Link: Bioretention Cell #3 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.257 C-70 1.11-Year 100.296 1.25-Year 100.328 2.00-Year 100.422 3.33-Year 100.500 5-Year 100.553 10-Year 100.630 25-Year 100.752 50-Year 100.811 100-Year 100.865 ********** Link: Bioretention Cell #4 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.292 1.11-Year 100.333 1.25-Year 100.367 2.00-Year 100.469 3.33-Year 100.558 5-Year 100.614 10-Year 100.693 25-Year 100.822 50-Year 100.877 100-Year 100.950 ********** Link: Bioretention Cell #5 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.129 1.11-Year 100.171 1.25-Year 100.200 2.00-Year 100.310 3.33-Year 100.410 5-Year 100.474 10-Year 100.600 25-Year 100.742 50-Year 100.824 100-Year 100.934 ********** Link: Bioretention Cell #6 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.100 1.11-Year 100.122 1.25-Year 100.151 C-71 2.00-Year 100.227 3.33-Year 100.287 5-Year 100.326 10-Year 100.388 25-Year 100.454 50-Year 100.546 100-Year 100.659 ********** Link: Bioretention Cell #7 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.057 1.11-Year 100.071 1.25-Year 100.089 2.00-Year 100.145 3.33-Year 100.184 5-Year 100.215 10-Year 100.263 25-Year 100.343 50-Year 100.370 100-Year 100.437 ********** Link: Bioretention Cell #8 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.132 1.11-Year 100.157 1.25-Year 100.179 2.00-Year 100.260 3.33-Year 100.316 5-Year 100.352 10-Year 100.401 25-Year 100.509 50-Year 100.597 100-Year 100.616 ********** Link: Bioretention Cell #9 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.002 1.11-Year 100.003 1.25-Year 100.003 2.00-Year 100.004 3.33-Year 100.005 C-72 5-Year 100.006 10-Year 100.012 25-Year 100.035 50-Year 100.088 100-Year 100.311 ********** Link: Bioretention Cell #10 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.267 1.11-Year 100.305 1.25-Year 100.338 2.00-Year 100.433 3.33-Year 100.513 5-Year 100.576 10-Year 100.647 25-Year 100.772 50-Year 100.863 100-Year 100.937 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 2476.023 _____________________________________ Total: 2476.023 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Developed 861.729 Subbasin: Developed Cell #1 64.133 Subbasin: Developed Cell #2 18.213 Subbasin: Developed Cell #3 21.249 Subbasin: Developed Cell #4 11.805 Subbasin: Developed Cell #5 10.456 Subbasin: Developed Cell #6 7.757 Subbasin: Developed Cell #7 18.888 Subbasin: Developed Cell #8 94.111 Subbasin: Developed Cell #9 109.494 Subbasin: Developed Cell #10 63.674 Subbasin: SR-507 Undeveloped 151.701 Link: Retention Pond 1454.849 Link: Bioretention Cell #1 Not Computed Link: Min. Reqmt. #7 0.000 Link: Bioretention Cell #2 Not Computed Link: Bioretention Cell #3 Not Computed C-73 Link: Bioretention Cell #4 Not Computed Link: Bioretention Cell #5 Not Computed Link: Bioretention Cell #6 Not Computed Link: Bioretention Cell #7 Not Computed Link: Bioretention Cell #8 Not Computed Link: Bioretention Cell #9 Not Computed Link: Bioretention Cell #1 Not Computed _____________________________________ Total: 2888.057 Total Predevelopment Recharge is Less than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 15.671 ac-ft/year, Post Developed: 18.279 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 12 ********** Link: Retention Pond ********** 15-Minute Timestep, Water Quality Treatment Design DischargeOn-line Design Discharge Rate (91% Exceedance): 0.47 cfsOff-line Design Discharge Rate (91% Exceedance): 0.26 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 1454.85 Inflow Volume Including PPT-Evap (ac-ft): 1454.85 Total Runoff Infiltrated (ac-ft): 1454.85, 100.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.00 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 100.00% ********** Link: Min. Reqmt. #7 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 0.01 Inflow Volume Including PPT-Evap (ac-ft): 0.01 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 0.01 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* C-74 Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: Min. Reqmt. #7 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 7.212E-03 2-Year 0.000 5-Year 7.444E-03 5-Year 0.000 10-Year 7.491E-03 10-Year 0.000 25-Year 7.688E-03 25-Year 0.000 50-Year 1.007E-02 50-Year 0.000 100-Year 1.603E-02 100-Year 0.000 200-Year 2.026E-02 200-Year 2.065E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -99.9% PASSMaximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -98.3% PASSMaximum Excursion from Q2 to Q50 (Must be less than 10%): -63.2% PASSPercent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -100.0%PASS Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -99.9%PASS ------------------------------------------------------------------------------------------------- MEETS ALL LID DURATION DESIGN CRITERIA: PASS C-75 APPENDIX “D” BIOFILTRATION SWALE CALCULATIONS, CONVEYANCE PIPE MGS FLOOD OUTPUT, MANNING’S EQUATION FOR PIPE D-1 Cruz Development BMP T9.10 (reference Section V-7, Volume V, SWMMWW) Design Calculations for Biofiltration Swale Use: b ~ [2.5Qn / 1.49(y)1.67 (s)0.5 - Zy] where b = swale bottom width, feet Q = flow = 0.47 cfs n = runoff coefficient = 0.24 y = water depth = 4 in = 0.33 ft s = channel slope = 0.005 ft/ft Z = side slope (horiz.) = 4 b ~ [2.5(0.47)(0.24) / 1.49(0.33)1.67 (0.005)0.5 - (4)(0.33) b ~ 0.282/0.0165 - 1.32 ~ 15.771 ft => Set b = 5 ft Check: V = KQ/A where V = velocity, fps K = 2.37 from Fig. V-7.7 of SWMMWW Q = 0.47 cfs A = by + Zy2 where b = 5 feet y = 0.33 feet Z = 4 A = (5)(0.33) + (4)(0.33)2 = 2.0856 ft2 V = (2.37)(0.47) / (2.0856) = 0.5341 fps < 1.0 fps, therefore, okay with b = 5 ft Determine biofiltration swale length, L L = Vt where V = velocity = 0.5341 fps t = residence time = 9 minutes L = (0.5341)(9 min)(60 sec/min) = 288.41 feet => Use 307 feet Stability Check Where: Q100 = 3.272 cfs Vegetation Coverage = Good Degree of Retardance (Table V-7.2) = D. Low Vmax = 3 fps Manning’s n = 0.04 VRapprox. (from Figure V-7.9) = 3 ft2/s R = VRapprox. / Vmax = 3 ft2/s / 3 fps = 1.0 ft VRactual = (1.49/n)R1.67s0.5 = (1.49/0.04)(1.0)1.67(0.005)0.5 = 2.63 ft2/s D-2 Select new Manning’s n = 0.038 VRapprox. (from Figure V-7.9) = 3.40 ft2/s R = 3.40 ft2/s / 3 fps = 1.13 ft VRactual = (1.49/0.038)(1.13)1.67(0.005)0.5 = 3.40 ft2/s VRactual within 5% of VRapprox., therefore R = 1.13 ft okay V = VRactual / R = 3.40 / 1.13 = 3.00 fps < Vmax, therefore okay Astability = Q100 / V = 3.272 / 3.00 = 1.09 ft2 < A, therefore bioswale passes stability check D-3 Figure V-7.7: Ratio of SBUH Peak/WQ Flow (Online) 2019 Stormwater Management Manual for Western Washington Volume V -Chapter 7 -Page 859 Per Table III-C.1, Vol. III, 6-month, 24-Hour Precipitation at Olympia = 1.74 inches. 1.74 2.37 D-4 Figure V-7.9: The Relationship of Manning’s n with VR for Various Degrees of Flow Retardance (A-E) 2019 Stormwater Management Manual for Western Washington Volume V -Chapter 7 -Page 862D-5 Stability Check Steps (SC) The stability check must be performed for the combination of highest expected flow and least veget- ation coverage and height. A check is not required for biofiltration swales that are located "off-line" from the primary conveyance/detention system (see Guidance for Bypassing Off-line Biofiltration Swales). Maintain the same units as in the biofiltration swale capacity analysis detailed above. 1.Step SC-1: Perform the stability check for the 100-year, return frequency flow using 15- minute time steps using an approved continuous runoff model. 2.Step SC-2: Estimate the vegetation coverage ("good" or "fair") and height on the first occasion that the biofiltration swale will receive flow, or whenever the coverage and height will be least. Avoid flow introduction during the vegetation establishment period by timing planting or bypassing. 3.Step SC-3: Estimate the degree of retardance from Table V-7.2: Guide for Selecting Degree of Retardance. When uncertain, be conservative by selecting a relatively low degree. The maximum permissible velocity for erosion prevention (Vmax) is 3 feet per second. Coverage Average Grass Height (inches)Degree of Retardance Good < 2 E. Very Low 2 - 6 D. Low 6 - 10 C. Moderate 11 - 24 B. High > 30 A. Very High Fair < 2 E. Very Low 2 - 6 D. Low 6 - 10 D. Low 11 - 24 C. Moderate > 30 B. High See (Chow, 1959). In addition, Chow recommended selection of retardance C for a grass-legume mixture 6-8 inches high and D for a mixture 4-5 inches high. No retardance recommendations have appeared for emergent wetland species. Therefore, judgment must be used. Since these species generally grow less densely than grasses, using a "fair" coverage would be a reasonable approach. Table V-7.2: Guide for Selecting Degree of Retardance 4.Step SC-4: Select a trial Manning's n for the high flow condition. The minimum value for poor vegetation cover and low height (possibly, knocked from the vertical by high flow) is 0.033. A good initial choice under these conditions is 0.04. 2019 Stormwater Management Manual for Western Washington Volume V -Chapter 7 -Page 861D-6 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200810005 Project Simulation Performed on: 02/24/2020 11:47 AM Report Generation Date: 02/24/2020 11:47 AM ————————————————————————————————— Input File Name: 9339_Cruz_Building Developed Q.fld Project Name: Cruz Development Analysis Title: Building Developed Flows Comments: Determine Q from building impervious 0.275 AC (12,000 SF) for pipe sizing ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.275 0.275 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.275 0.275 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Predeveloped ---------- -------Area (Acres) -------- Outwash Forest 0.275 ---------------------------------------------- Subbasin Total 0.275 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 D-7 ---------- Subbasin : Building Impervious ---------- -------Area (Acres) -------- Impervious 0.275 ---------------------------------------------- Subbasin Total 0.275 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Copy Lnk1 Link Type: Copy Downstream Link: None **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Copy Lnk1 ********** Link Inflow Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 0.102 5-Year 0.133 10-Year 0.150 25-Year 0.189 50-Year 0.240 100-Year 0.277 200-Year 0.288 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures D-8 Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Predeveloped 72.980 _____________________________________ Total: 72.980 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Building Impervious 0.000 Link: New Copy Lnk1 0.000 _____________________________________ Total: 0.000 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.462 ac-ft/year, Post Developed: 0.000 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Copy Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 123.30 Inflow Volume Including PPT-Evap (ac-ft): 123.30 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 123.30 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Predeveloped Scenario Postdeveloped Compliance Link: New Copy Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- D-9 2-Year 2.126E-04 2-Year 0.102 5-Year 2.194E-04 5-Year 0.133 10-Year 2.208E-04 10-Year 0.150 25-Year 2.266E-04 25-Year 0.189 50-Year 2.968E-04 50-Year 0.240 100-Year 4.726E-04 100-Year 0.277 200-Year 5.972E-04 200-Year 0.288 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals D-10 Inputs: Pipe Diameter, dₒ15.0000 in Manning Roughness, n 0.0130 Pressure slope (possibly equal to pipe slope), S₀ 0.0030 slope Percent of (or ratio to) full depth (100% or 1 if flowing full) 1.0000 fraction Results: Flow, Q 3.5380 ft^3/s Velocity, v 2.8830 ft/s Velocity head, hv 0.1292 ft Flow Area, A 1.2272 ft^2 Wetted Perimeter, P 3.9270 ft Hydraulic Radius 0.3125 ft Top Width, T 0.0000 ft Froude Number, F 0.00 Shear Stress (tractive force), τ 0.2341 psf Manning Formula Uniform Pipe Flow at Given Slope and Depth Version 2.0 (20 June 2017) HawsEDC Calculators 15-inch pipe from bioswale outlet catch basin to infiltration pond D-11 Inputs: Pipe Diameter, dₒ6.0000 in Manning Roughness, n 0.0130 Pressure slope (possibly equal to pipe slope), S₀ 0.0050 slope Percent of (or ratio to) full depth (100% or 1 if flowing full)1.0000 fraction Results: Flow, Q 0.3967 ft^3/s Velocity, v 2.0206 ft/s Velocity head, hv 0.0635 ft Flow Area, A 0.1963 ft^2 Wetted Perimeter, P 1.5708 ft Hydraulic Radius 0.1250 ft Top Width, T 0.0000 ft Froude Number, F 0.00 Shear Stress (tractive force), τ 0.1561 psf Manning Formula Uniform Pipe Flow at Given Slope and Depth Version 2.0 (20 June 2017) HawsEDC Calculators 6-inch pipe from building roof tightline to bioswale outlet catch basin D-12