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8.d1 Bliss Addition ReportCity of Scandia, MN Bliss Addition Stormwater Planning November 2019 Submitted by: Bolton & Menk, Inc. 2035 County Rd D East Maplewood, MN 55109 P: (651) 704-9970 F: (651) 704-9971 Prepared by: Bolton & Menk, Inc. Certification Bliss Addition Stormwater Planning ǀ N13.118317 Certification Feasibility Report For Bliss Addition Stormwater Planning City of Scandia, MN N13.118317 November 2019 I hereby certify that this plan, specification or report was prepared by me or under my direct supervision, and that I am a duly Licensed Professional Engineer under the laws of the State of Minnesota. By: Timothy J. Olson, P.E. License No. PE - 49129 Date: DRAFT Prepared by: Bolton & Menk, Inc. Table of Contents Bliss Addition Stormwater Planning ǀ N13.118317 Table of Contents INTRODUCTION ............................................................................................................................................. 1 PUBLIC ENGAGEMENT PROCESS ................................................................................................................... 2 SUMMARY OF CURRENT DRAINAGE CONDITIONS ....................................................................................... 2 SUMMARY OF PROPOSED STORMWATER MANAGEMENT .......................................................................... 3 NORTH MANAGEMENT AREA STORMWATER MANAGEMENT ..................................................................... 5 SOUTH MANAGEMENT AREA STORMWATER MANAGEMENT ..................................................................... 7 WATER QUALITY TREATMENT ...................................................................................................................... 8 VOLUME CONTROL ....................................................................................................................................... 9 ESTIMATED COSTS ........................................................................................................................................ 9 Tables Table 1 – BMP Pollutant Removal Summary – North Management Area .................................................... 9 Table 2 – BMP Pollutant Removal Summary – South Management Area .................................................... 9 Table 3 – Estimated Costs ........................................................................................................................... 10 Exhibits Exhibit 1: Example marked up map from public meeting. ........................................................................... 2 Exhibit 2: Detail of modified infiltration ditch section, showing expanded surface storage and turf grass. 4 Exhibit 3: Example modified infiltration ditch with mature native plants. ................................................... 4 Exhibit 4: Bioinfiltration basin/rain garden detail. ....................................................................................... 5 Exhibit 5: Photo of a bioinfiltration basin with native plants. ...................................................................... 5 Exhibit 6: Example construction details for heavy sediment and gross solids treatment cell..................... 6 Exhibit 7: Photo of heavy sediment and gross solids capture treatment cell. ............................................ 7 Appendix Appendix A: Figures Appendix B: Preliminary Cost Estimates Appendix C: MIDS Output Appendix D: Comprehensive Surface and Infiltration Volume Comparison Table Prepared by: Bolton & Menk, Inc. INTRODUCTION Bliss Addition Stormwater Planning ǀ N13.118317 Page 1 INTRODUCTION The Bliss Addition residential neighborhood resides immediately adjacent to Big Marine Lake, located in the Carnelian-Marine-St. Croix Watershed District (CMSCWD). Big Marine Lake is a high quality 1,621-acre deep water recreational lake in the Twin Cities Metropolitan area. The lake has a popular public access as well as 328 shoreland parcels. Due to past efforts of the watershed and landowners the lake as a minimally improving trend for total phosphorus and secchi depth. The 2016 MLCCS identifies 24% of the 5,262-acre watershed as developed (1,262 acres). The Bliss Addition is comprised of 39 acres of residential development that discharges directly to Big Marine Lake by uncontrolled overland flow, wet ditches and culverts. The Bliss Addition has been identified as an area that could be equipped with stormwater management best management practices (BMPs) to achieve the following goals. · Improve water quality and reduce inflow volume to Big Marine Lake. · Mitigate routine surface flooding in the ditch areas and low points during relatively small rain fall events. The Bliss Addition is marked by steep topography directed toward the lake, high ground water in the lower elevations adjacent to the lake and is drained by roadway ditches and a culvert system to convey water to and from wetland areas. The combination of these three items make it prone to surface flooding. These conditions have been verified through two public meetings where residents identified known flooding concerns, and their likely causes, on large maps. The following critical factors were identified by residents and confirmed by City staff, which were used to inform proposed stormwater management strategies. · Ditches have filled with sediment and culverts have plugged over time. The residents identified other maintenance issues throughout the neighborhood that may have led to surface flooding. · Infiltration capacity has been lost due to roadway compaction. Restoration of native soils would be beneficial. · High groundwater elevations, especially in the lowest areas around the lake, perpetuate surface flooding and restrict infiltration. While the lake has an outlet control structure, the elevations appear to be on the rise, especially when correlated to increases in rainfall depth and intensity over the last decade. The primary goal of this study was to identify cost effective locations to reduce total phosphorus (TP) and total suspended solids (TSS) through small storm volume retention, larger storm detention, and improved conveyance for the 1-year storm event (2.4 inches). The proposed stormwater management solutions: · Increase small storm retention volumes by 6,111 cubic feet. · Reduce TP discharging to Big Marine Lake by 9.9 lbs per year and TSS by 1,531 lbs per year (estimated with the MIDS Calculator). · Improve storm water conveyance to reduce erosion and flooding. The stormwater management solutions focus on enhancing existing surface storage features, constructing new surface storage BMP’s, and installing storm sewer infrastructure within public right-of-way to effectively convey stormwater to the lake. Two major local drainage areas were investigated, described as follows. Refer to Figure 1 for a location map of each drainage area. · North Management Area o The North Management Area consists of all areas along Larkspur Avenue N and Layton Avenue N, north of the existing Larkspure Avenue N centerline highpoint; just north of 190th Street N. Prepared by: Bolton & Menk, Inc. PUBLIC ENGAGEMENT PROCESS Bliss Addition Stormwater Planning ǀ N13.118317 Page 2 · South Management Area o The South Management Area includes all areas to the south of the North Management Area, along Langly Ave N, Layton Avenue N, 190th Street N, and 189th Street N. PUBLIC ENGAGEMENT PROCESS Residents of the Bliss Addition have decades of history in the area and many have seen long term changes in drainage in the neighborhood and lake elevations. As such, the City engaged the neighborhood through two public meetings, described as follows. April 16, 2019 – First public meeting, approximately 20 to 30 residents attended. Preliminary aerial maps showing the neighborhood and general drainage patterns were presented for general conversation. The group was split into the north and south halves of the neighborhood so comments could be written directly on the maps (example shown in Exhibit 1). Residents described their drainage concerns and shared in depth history of their time on the lake. August 20, 2019 – Second public meeting, approximately 20 to 30 residents attended. Preliminary drainage and water quality improvements were discussed. Aerial maps were presented for residents to mark up and comment. General open discussion was held followed by individual conversations. Best management practices were modified based on the publics input. The final plan will be presented at a regular City Council meeting and CMSCWD Board Meeting for final approval. The City Council meeting will be a more formal presentation of the final report and serve as the final public engagement. Exhibit 1: Example marked up map from public meeting. SUMMARY OF CURRENT DRAINAGE CONDITIONS Existing and proposed drainage conditions were analyzed using Autodesk’s Storm and Sanitary Analysis (SSA) software which utilizes NRCS TR-20 methodologies to hydrodynamically route stormwater through the drainage system. Numerous rainfall events were analyzed include the 1-year (2.42”), 2-year Prepared by: Bolton & Menk, Inc. SUMMARY OF PROPOSED STORMWATER MANAGEMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 3 (2.80”), 10-year (4.15”) and 100-year (7.00”), 24-hour events. The MSE 3 nested rainfall distribution was also utilized. Figure 2 identifies drainage boundaries and ditch areas assessed in this analysis. Routine flooding has been observed, and verified by hydrologic and hydraulic modeling, which is largely attributed to three common factors. 1. Existing surface storage features, consisting of linear roadside ditches, provide nominal storage during rainfall events due to narrow right-of-way corridors which cannot accommodate inflow volumes. Further, accumulated sediment transported during rain and ice melt events resides in existing roadside ditches which reduces infiltration and storage capacities. 2. High water table elevations within the neighborhood due to recent years of higher than average annual rainfall depths create a condition where standing water is present within the majority of existing roadside ditches during non-rain events, especially in the lowest areas near the lake. This pre-existing condition reduces total available storage volumes, along with infiltration capacities, within the neighborhood which would otherwise be utilized for effectively managing and storing runoff during storm events. 3. Relatively steep topography within both drainage areas presents an environment that produces higher runoff volumes and surface flow velocities during rain events. This in turn, along with accumulated sediment and high ground water within existing drainage ditches, accelerates the inundation at low points which can exceed outlet capacities at existing storm management features and result in the flooding of adjacent areas. The last 10 to 20 years of rainfall record show an increase in rainfall intensity and a decrease in rainfall duration. More rain in a shorter period of time combined with fast rates of runoff perpetuate flooding. Survey data of the existing storm sewer, culvert pipe sizes and surface topography within the right of way was collected. Also, light detection and ranging (LiDAR) surface topography was supplemented outside of the right of way were provided utilizing the city-wide GIS and survey data. Existing soil data was provided utilizing soils recognized on the NRCS Web Soil Survey. Soil borings should be collected prior to final design to verify soil and groundwater data. SUMMARY OF PROPOSED STORMWATER MANAGEMENT Proposed stormwater management solutions for two primary drainage areas in the neighborhood have been developed and are described below. Figures 1 and 2 show the extents of each Management Area along with existing stormwater infrastructure. Best management practices (BMPs) were selected that consider space limitations, possible volume reduction and water quality benefit and long-term maintenance requirements. Two primary BMPs were selected throughout the management areas, which include the following. A. Modified Infiltration Ditches – These BMPs consist of re-grading ditch side slopes and installing a 30” deep filtration trench of sand and bioretention media, equipped with a 6” perforated PVC underdrain and outlet control valve, in order to increase storage capacities and enhance infiltration. The 30” excavation will also expose native, less compacted sandy soils. The enhanced infiltration ditch includes native plants, or mowed turf grass, at the surface. Exhibit 2 is a detail of the modified ditch section and Exhibit 3 is an example of an infiltration ditch planted with mature native plants. Prepared by: Bolton & Menk, Inc. SUMMARY OF PROPOSED STORMWATER MANAGEMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 4 Exhibit 2: Detail of modified infiltration ditch section, showing expanded surface storage and turf grass. Exhibit 3: Example modified infiltration ditch with mature native plants. B. Bioinfiltration Basin/Rain Garden – Bioinfiltration basins, also known as rain gardens, are a popular stormwater management practice that includes excavation of compacted soils, replacement with an engineered soil blend consisting of clean sand and compost, and native plantings. Several areas throughout the Bliss Addition are conducive to bioinfiltration basin construction. These BMPs have a larger footprint than the modified infiltration ditches and can handle a larger drainage area. Exhibit 4 is a detail of bioinfiltration basin and Exhibit 5 is an example photo. Prepared by: Bolton & Menk, Inc. NORTH MANAGEMENT AREA STORMWATER MANAGEMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 5 Exhibit 4: Bioinfiltration basin/rain garden detail. Exhibit 5: Photo of a bioinfiltration basin with native plants. NORTH MANAGEMENT AREA STORMWATER MANAGEMENT EXISTING CONDITIONS The North Management Area accounts for approximately 22 acres of the Bliss Addition residential area, comprised primarily of rural section drainage, which are considered streets without curb and gutter. A short stretch of existing curb is located along the south edge of 192nd Street North, conveying runoff to the south, into a drainage ditch along Layton Avenue N. Drainage ditches running parallel along Larkspur Avenue N and Layton Avenue N, collect and convey flows to the east, ultimately crossing under Layton Avenue N and discharging into Big Marine Lake. Figure 2 shows the existing ditches and storm sewer for the North Management Area. The north end of Layton Avenue N drains to a low area and a culvert that is prone to flooding. As the ditches fill, the roadway becomes inundated and overtops, forcing stormwater to discharge overland Prepared by: Bolton & Menk, Inc. NORTH MANAGEMENT AREA STORMWATER MANAGEMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 6 between homes and into the lake. The flooding problem is further perpetuated under repeat rainfall conditions (multiple events over consecutive days), when the water table is high, or if the culvert is partially plugged. The southern-most outlet consists of a 12” reinforced concrete pipe (RCP) culvert (near Ditch 12) that routes runoff generated from approximately 4 acres of Layton Avenue N corridor and adjacent residential area drainage, to the east into Big Marine Lake. Existing infrastructure consists primarily of roadside culverts ranging from 12” corrugated metal pipe (CMP) and increasing to 18” CMP, with roadside ditches being the primary conveyance system within the management area. Refer to Figure 5 for a flood inundation map showing the extents of the 10-year flood (4.15” in 24 hours). PROPOSED SOLUTION The proposed water quality and drainage management solution for the North Management Area is shown in Figure 3. Modified infiltration ditches are shown through the North Management Area. Also, the numbered reference locations in the figure are further described below. Location 1 - Water quality improvements include the installation of a bioinfiltration basin along the north end of the management area which would collect and treat runoff captured from a proposed catch basin along the curbed section of 192nd Street N. The bioinfiltration basin would be equipped with a forebay pretreatment cell in order to ensure the longevity of the feature’s treatment performance. Existing topography at the outlet of the basin would also be slightly regraded in order to ensure any and all discharge stays within city-owned property. Location 2 - Routine maintenance and removal of accumulated sediment in the downstream-most ditch of the Layton Avenue N network will be accomplished by constructing a heavy sediment and gross solids clean out area. This consists of a concrete paver ditch bottom at the width of a skid-steer loader, rip rap armored side slopes and a slotted filter weir. This specific technique was designed by the Middle St. Croix Watershed Management Organization, and detailed below in Exhibits 6 and 7. Exhibit 6: Example construction details for heavy sediment and gross solids treatment cell. Prepared by: Bolton & Menk, Inc. SOUTH MANAGEMENT AREA STORMWATER MANAGEMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 7 Exhibit 7: Photo of heavy sediment and gross solids capture treatment cell. Location 3 - The existing Larkspur Avenue N drainage could be rerouted to the west into the existing wetland along Langley Ave N, through an 8” HDPE pipe. A perched drop structure with an 18” RCP outlet would be installed at the existing Larkspur Avenue N outlet to capture and convey runoff to the east, maintaining existing drainage patterns, during storm events where the capacity of the proposed 8” HDPE pipe would be exceeded. While an expensive solution, redirection of the discharge to west into the wetland area will have a substantial impact on the flooding in the low areas to the east along Layton. In fact, the partial reallocation of runoff volumes, along with the increase in infiltration and conveyance capacity, will allow the system to adequately convey the entire 10-year storm event without surface flooding. The discharge to the east toward Layton Ave will be reduced, so no additional work is proposed between the Larkspur and Layton. Location 4 - In addition, improvements along Layton Avenue N will focus on reconstructing a portion of the roadway to cross-slope toward the west direction by lowering the western most edge of pavement. This will in turn promote runoff to drain toward roadside ditches and into the culvert, as well as minimize roadway overtopping. Figure 5 shows the existing versus proposed inundation limits for a 10-year rainfall event. SOUTH MANAGEMENT AREA STORMWATER MANAGEMENT EXISTING CONDITIONS The South Management Area accounts for approximately 17 acres of the Bliss Addition residential area, comprised primarily of rural section drainage, which are considered streets without curb and gutter. The South Management Area also accommodates the main drainage way for an existing 83-acre wetland complex which outlets under 190th Street N and is routed to the southeast before ultimately crossing under Layton Avenue N and discharging into Big Marine Lake. Figure 2 shows the existing ditches and storm sewer for the South Management Area. Two main discharge points are within the South Management Area. The north outlet consists of a 24” RCP culvert (near Ditch 15 system) that conveys 90 acres of drainage consisting of wetland, roadway corridor, and residential area drainage. The existing culvert routes upstream flows under Layton Avenue Prepared by: Bolton & Menk, Inc. WATER QUALITY TREATMENT Bliss Addition Stormwater Planning ǀ N13.118317 Page 8 N before ultimately discharging into Big Marine Lake. The south outlet consists of a 12” corrugated metal pipe (CMP) culvert (near Ditch 26) which conveys 2 acres of residential area and roadway corridor drainage under Layton Avenue N, discharging into Big Marine Lake. Lastly, the remaining 4 acres of the South Management Area is located along the banks of Big Marine Lake where generated runoff is discharged directly into the lake. Areas along Larkspur Avenue N and Layton Avenue N experience minor surface ponding during the 10- year event due to insufficient surface storage and downstream storm sewer capacities. PROPOSED SOLUTION The proposed water quality and drainage management solution for the North Management Area is shown in Figure 4. Modified infiltration ditches are shown through the South Management Area. Also, the numbered reference locations in the figure are further described below. Location 5 - Improvements also include the installation of a bioinfiltration basin along 190th Street N, adjacent to the existing wetland. In order to achieve a higher capture and treatment efficiency, an existing 12” CMP located at the corner of 190th Street N and Larkspur Avenue N would be either removed or plugged, in order to force drainage from the Larkspur corridor to the west, rather than to the south. Location 6 – Due to a conflict with the existing sanitary sewer lift station, a new culvert under 189th St N conveys stormwater into an area with a wider right of way. The existing ditches further east along 189th St N could be enhanced to promote infiltration but could be impacted by high groundwater. The increase in infiltration and conveyance capacity based on the proposed improvements will allow the system to adequately convey the entire 10-year storm event without surface flooding. WATER QUALITY TREATMENT A direct comparison of the existing and proposed SSA models indicates that the implementation of the proposed BMPs around the Bliss Addition residential area provides an increase in upstream flow attenuation and volume reduction through infiltration. The benefits of this volume decrease have been quantified using the Minimal Impact Design Standards (MIDS) best management practice (BMP) calculator to determine the potential pollutant loads for the proposed conditions and the potential load reductions provided by BMPs. Project segments covering all direct contributing surfaces within the Bliss Addition residential area and associated BMPs were entered into the MIDS calculator in order to compute volume control, Total Phosphorus (TP) and Total Suspended Solids (TSS) load reductions. BMPs included all enhanced ditches, bioinfiltration basins, and infiltration gallery. MIDs summary printouts are provided in Appendix C, with Table 1 and 2 providing a summary of the results. Prepared by: Bolton & Menk, Inc. VOLUME CONTROL Bliss Addition Stormwater Planning ǀ N13.118317 Page 9 Table 1 – BMP Pollutant Removal Summary – North Management Area Particulate Phosphorus Dissolved Phosphorus Total Suspended Solids BMP Name Inflow Load Load Retained Percent Retained Inflow Load Load Retained Percent Retained Inflow Load Load Retained Percent Retained (lbs) (lbs) (%) (lbs) (lbs) (%) (lbs) (lbs) (%) Ditch-01 0.99 0.85 86% 0.92 0.41 44% 339.70 245.44 72% Ditch-02 0.07 0.07 98% 0.05 0.05 94% 21.99 21.32 97% Ditch-03 0.37 0.36 95% 0.31 0.25 81% 123.58 111.78 90% Ditch-04 0.07 0.06 84% 0.11 0.04 37% 30.06 20.52 68% Ditch-05 0.15 0.13 86% 0.13 0.06 45% 50.62 36.62 72% Ditch-07 0.96 0.84 87% 0.79 0.38 49% 316.99 236.19 75% Ditch-11A 0.57 0.52 92% 0.47 0.31 66% 188.87 156.97 83% Biobasin-1N 0.92 0.91 99% 0.75 0.72 95% 304.77 298.08 98% TOTAL 4.11 3.74 91% 3.52 2.22 63% 1376.58 1126.92 82% Table 2 – BMP Pollutant Removal Summary – South Management Area Particulate Phosphorus Dissolved Phosphorus Total Suspended Solids BMP Name Inflow Load Load Retained Percent Retained Inflow Load Load Retained Percent Retained Inflow Load Load Retained Percent Retained (lbs) (lbs) (%) (lbs) (lbs) (%) (lbs) (lbs) (%) Ditch-20 0.40 0.38 94% 0.37 0.28 77% 67.95 60.05 88% Ditch-18 1.19 0.98 83% 1.04 0.31 30% 200.26 130.27 65% Ditch-21 0.09 0.08 89% 0.10 0.06 55% 16.57 12.86 78% Ditch-22 0.17 0.16 92% 0.14 0.09 68% 28.10 23.57 84% Biobasin-1S 1.35 1.16 86% 1.11 0.47 43% 223.25 159.46 71% TOTAL 3.20 2.75 86% 2.75 1.22 44% 536.13 386.21 72% The MIDs models indicate that the proposed BMPs located within the North Management area expect an 81% TP and 84% TSS reduction, while BMPs located within the South Management area expect an 69% TP and 74% TSS reduction. VOLUME CONTROL Restoring ditch volume and infiltration capacity throughout the Bliss Addition will help control runoff volumes for small rainfall events (approximately a 1-year rainfall even, 2.4” in 24 hours). Table 3 located in Appendix D summarizes the current runoff volumes and ditch capacities, as well as the proposed improvements. ESTIMATED COSTS The estimated project costs are summarized in Table 3 and are divided by Management Area. The table shows the individual subtotal of construction costs, the associated costs per pound of pollutant removed, and the total project cost. These costs reflect only the construction costs for storm sewer and water quality improvements including a contingency factor of 10%. Also, a 25% allowance factor has been included to account for legal, engineering, administrative and fiscal costs. Final costs will be determined using actual bid construction costs of the proposed work. A more detailed breakdown of estimated construction costs is itemized in Appendix B. Prepared by: Bolton & Menk, Inc. ESTIMATED COSTS Bliss Addition Stormwater Planning ǀ N13.118317 Page 10 Table 3 – Opinion of Estimated Costs IMPROVEMENT ITEM ESTIMATED COSTS A - NMA Enhanced Ditch Improvements Subtotal $ 166,360 - Enhanced Ditch Improvements ($/LB TP Removed) $ 38,420 - Enhanced Ditch Improvements ($/LB TSS Removed) $ 200 B - NMA Bioinfiltration Basin Improvements Subtotal $ 34,100 - Bioinfiltration Basin Improvements ($/LB TP Removed) $ 20,920 - Bioinfiltration Basin Improvements ($/LB TSS Removed) $ 114 C - NMA Layton Avenue N. Roadway Improvements Subtotal $ 30,620 D - NMA 8” HDPE Directional Drilling Improvements Subtotal $ 96,220 North Management Area Improvements Overall Total (A+B+C+D) $ 327,300 E - SMA Enhanced Ditch Improvements Subtotal $ 89,380 - Enhanced Ditch Improvements ($/LB TP Removed) $ 38,197 - Enhanced Ditch Improvements ($/LB TSS Removed) $ 394 F - SMA Bioinfiltration Basin Improvements Subtotal $ 13,310 - Bioinfiltration Basin Improvements ($/LB TP Removed) $ 8,166 - Bioinfiltration Basin Improvements ($/LB TSS Removed) $ 83 South Management Area Improvements Overall Total (E+F) $ 102,690 Appendix A: Figures ! ! ! !. j jjjj jj j jj j j j j jj j j jjS_WETLAND Layton Ave NLarkspur Ave NLangley Ave N 1 8 9 t h S t N 1 9 0 th S t N 192nd St N Map Document: H:\SCND\N13118317\GIS\Figures\Figure-1_TJO.mxd | Date Saved: 10/23/2019 12:56:54 PMBliss Sto rm wa ter PlanningCity of Scandia, MN Figure 1 - Manag e me n t Area Ma pNovember 20 19 Leg end Nation al Wetla nd In vento ry Stream Man agement Area Boun d. !Ex. S torm M an hole !.Ex. Ar ea In let Existing Ditche s j Existing Flow Directio n 0 150Feet Source: MnDOT, Wa shington Cou nty, City o f S candia !I BIG MARINE LAKE Nor th M ana gem e nt Area So u th Ma n agement Area ! ! ! !. j jjjj jDITCH -15 j jj j j j j jj j j jj DITCH -31 DITCH -30 DITCH-29 DITCH -28 DITCH -27 DITCH -26 DITCH -25 DITCH -24 DITCH -23 DITCH -22 DITCH -21 DITCH -20 DITCH -19 DITCH-18 DITCH-16 DITCH -14 DITCH -13 DITCH -12 DITCH -11 DITCH -10 DITCH -09 DITCH -08 DITCH -07DITCH-06 DITCH -05 DITCH -04 DITCH -03 DITCH-02 DITCH -01 S_WETLAND Ditch-11A In d e x I n d e x I ndexIndexI nde x In d e x Index IndexIndexI nde x I n d e x In d e x I n d e x IndexIndex IndexI n d e x IndexI n d e x IndexIndexIndex IndexIndex IndexIndexI n d e x In d exIndex IndexI nde x Layton Ave NLarkspur Ave NLangley Ave N 1 8 9 t h S t N 1 9 0 th S t N 192nd S t N Map Document: H:\SCND\N13118317\GIS\Figures\Figure-2 - Existing Conditions - 10 year Inundation_TJO.mxd | Date Saved: 10/23/2019 11:14:37 AMBliss Sto rm wa ter PlanningCity of Scandia, MN Figure 2 - Dra in a g e Are a M apNovember 20 19 Legen d Water shed Bo unda ry Existing Ditches Existing Stor m Pip e !Ex. Storm M anhol e !.Ex. Ar ea Inlet j Existing Flow Dir ection 0 150Fe et !I BIG MARINE LAKE So urce : Mn DO T, Washin gtonCounty, City of Sca ndia ! !. !. !. !. !. " j jjjj j DITCH-07 DITCH-08 DITCH-09 DITCH-10 DITCH-11 DITCH-11 A DITCH-14 DITCH-13 DITCH-12 DITCH-21 DITCH-22 DITCH-20 DITCH-19 AI-21 DITCH-16 DITCH-25 DITCH-15 DITCH-31 DITCH-03 DITCH-01 DITCH-02 DITCH-04 DITCH-05 DITCH-06 Biobasi n-1N Biobasi n-1S j jj j j j j jj j j jjLayton Ave NLarkspur Ave N1 9 0 th S t N 192nd St N Map Document: H:\SCND\N13118317\GIS\Figures\Figure-3 - Proposed Improvements Map_TJO.mxd | Date Saved: 10/23/2019 1:11:16 PMBliss Sto rmwate r Pla nnin gCity of Scandia, MN Figu re 3 - North Mgmt Area I mp rovementsNovember 2019 Legend Existing Storm Sewer !Existing Storm Sewer Manhole Existing Ditches Proposed Subbasin Proposed RCP Storm Sewer !.Proposed Beehive Structure "Proposed Catch Basin Proposed Enhanced Ditch Proposed Bioinfiltration Basin Proposed 6-inch Draintile Proposed 8-inch Outlet j Proposed F low Direction Reshape & Grade Pavement 0 100Feet !I BIG MARINE LAK E Source: MnDOT, Washington County, City of Sca ndi a Propo sed NMA Improvement Description - 1 - Bioinfiltrati on basin treats runoff captured by new ca tch b asinand stor m sewer along 192nd St. N. Reduces flows to eastand so uth. 2 - A dde d curb cu ts along Layton Ave. N rou te road dra inageinto en hanced i nfiltration ditch section to reduce flows to the sou th.Ditch sectio ns to south are restored to increase surface storage. 3 - New 8" dir ection ally drilled outlet reroutes flows captured in enhan ced in fil tr ation ditch sections to the west into existingwetland. Redu ces fl ow to east. 4 - Pro pose d storm sewer routes road draina ge ca ptured inenhanced in fil tr ation ditch sections to the east, to re duce flowsto the nor th. ¬«1 ¬«2 ¬«4 ¬«3 ! ! ! !. DITCH-13 DITCH-12 DITCH-21 DITCH-22 DITCH-20 DITCH-19 AI-21 DITCH-16 DITCH-25 DITCH-15 DITCH-23DITCH-31 DITCH-30 DITCH-29DITCH-28 DITCH-26 DITCH-27 DITCH-24 Biobasi n-1S j jj j j j j Layton Ave NLangley Ave N 189th St N 1 9 0 th S t N Layton Ct NLarkspur Ave N187th St NMap Document: H:\SCND\N13118317\GIS\Figures\Figure-4 - Proposed Improvements Map_TJO.mxd | Date Saved: 10/23/2019 1:09:41 PMBliss Sto rmwate r Pla nnin gCity of Scandia, MN Figu re 4 - South Mgmt Area ImprovementsNovember 2019 Legend Existing Storm Sewer !Existing Storm Sewer Manhole Existing Ditches Proposed RCP Storm Sewer !.Proposed Beehive Structure "Proposed Catch Basin Proposed Enhanced Ditch Proposed Bioinfiltration Basin Proposed 6-inch Draintile Proposed 8-inch Outlet j Proposed F low Direction Reshape & Grade Pavement 0 100Fe et !I BIG MARINE LAK E Sou rce: MnDO T, Washin gton Coun ty, City of Scandi a Proposed SMA Impro vement Descrip tion - 5 - Enhan ced in fi ltration ditch sections r oute road d raina ge to thewest in to a bioinfiltration basin to redu ce vo lum es to we tland and ravin e. 6 - A ne w culvert un der 189 th St. N rer oute s south flows to th e nor th into an enh ance d infiltration ditch section to redu ce flo wsto the east. ¬«5 ¬«6 & & j IndexIn d e x IndexIndexIndexLayton Ave NMap Document: H:\SCND\N13118317\GIS\Figures\Figure-5 - Flood Innundation Map - TJO.mxd | Date Saved: 11/12/2019 2:45:42 PMBliss Sto rmwate r Pla nnin gCity of Scandia, MN Fig ur e 5 - Flood In n undatio n M apNovember 2019 Leg end Existing Storm Sewer Propo sed RCP Storm S ewer Ex 10-yr Fl ood Extents Prop 10-yr Flood Extents 0 40Fe etSource: !I Appendix B: Preliminary Cost Estimates No.ItemUnit Unit PriceEnhanced Ditch Section ImprovementsBioinfiltration Basin ImprovementsLayton Avenue N Roadway Improvements8" Directional Drill Pipe InstallationTotal Quantity Enhanced Ditch Section ImprovementsBioinfiltration Basin ImprovementsLayton Avenue N Roadway Improvements8" Directional Drill Pipe InstallationTotal Cost1MOBILIZATIONLUMP SUM 3,300.00$ - - - -0.5825.00$ 825.00$ 825.00$ 825.00$ 3,300.00$ 2TRAFFIC CONTROLLUMP SUM 500.00$ - - - -0.5125.00$ 125.00$ 125.00$ 125.00$ 500.00$ 3CLEARINGTREE 150.00$ 2.5 2.5 0 0 5 375.00$ 375.00$ -$ -$ 750.00$ 4GRUBBINGTREE 150.00$ 2.5 2.5 0 0 5 375.00$ 375.00$ -$ -$ 750.00$ 5SALVAGE AND REINSTALL SIGNEACH 200.00$ 0 0 0 0 0 -$ -$ -$ -$ -$ 6REMOVE AND REPLACE CURB AND GUTTERLIN FT 35.00$ 0 4 0 0 4 -$ 140.00$ -$ -$ 140.00$ 7REMOVE BITUMINOUS PAVEMENTSQ YD 5.00$ 16 39 0 0 55 82.22$ 194.44$ -$ -$ 276.67$ 8COMMON EXCAVATION (EV) (P)CU YD 11.00$ 1200 120 0 0 1320 13,200.00$ 1,320.00$ -$ -$ 14,520.00$ 9REMOVE 12" RCP STORM SEWERLIN FT 13.00$ 212 0 0 0 212 2,756.00$ -$ -$ -$ 2,756.00$ 10REMOVE MANHOLE, CATCH BASIN OR DROP INLET INCL CASTINGEACH 450.00$ 1 0 0 0 1 450.00$ -$ -$ -$ 450.00$ 11REMOVE FLARED END SECTIONEACH 400.00$ 1 0 0 0 1 400.00$ -$ -$ -$ 400.00$ 126" PERFORATED HDPE PIPE DRAINLIN FT 15.00$ 961 43 0 0 1004 14,415.00$ 645.00$ -$ -$ 15,060.00$ 138" HDPE PIPE SEWER-DIRECTIONAL DRILLEDLIN FT 120.00$ 0 0 0 586 586 -$ -$ -$ 70,320.00$ 70,320.00$ 1412" RC PIPE SEWER CLASS 5LIN FT 35.00$ 0 43 0 0 43 -$ 1,505.00$ -$ -$ 1,505.00$ 1515" RC PIPE SEWER CLASS 5LIN FT 40.00$ 212 47 0 0 259 8,480.00$ 1,880.00$ -$ -$ 10,360.00$ 1618" RC PIPE SEWER CLASS 5LIN FT 50.00$ 70 0 0 0 70 3,500.00$ -$ -$ -$ 3,500.00$ 1712" PERF PE PIPE DRAINLIN FT 80.00$ 0 0 0 0 0 -$ -$ -$ -$ -$ 18PVC VENTED CLEANOUTEACH 350.00$ 4 1 0 0 5 1,400.00$ 350.00$ -$ -$ 1,750.00$ 19PVC UNDER-DRAIN VALVE & VALVE BOXEACH 1,500.00$ 4 1 0 0 5 6,000.00$ 1,500.00$ -$ -$ 7,500.00$ 204' DIA STORM MH, INCL R-1642 CSTG AND HDPE ADJ RINGSEACH 3,000.00$ 0 0 0 0 0 -$ -$ -$ -$ -$ 21 4' BEEHIVE STRUCTURE W/ R4342 CASTINGEACH 5,500.00$ 2 1 0 0 3 11,000.00$ 5,500.00$ -$ -$ 16,500.00$ 22 2'X3' CB, INCL CSTGEACH 2,000.00$ 0 1 0 0 1 -$ 2,000.00$ -$ -$ 2,000.00$ 2312" FLARED END SECTION W/ TRASH GUARDEACH 1,250.00$ 0 1 0 0 1 -$ 1,250.00$ -$ -$ 1,250.00$ 2415" FLARED END SECTION W/ TRASH GUARDEACH 950.00$ 1 1 0 0 2 950.00$ 950.00$ -$ -$ 1,900.00$ 25RANDOM RIP RAP, CLASS IIICU YD 105.00$ 4.8 9.2 0 0 14 504.00$ 966.00$ -$ -$ 1,470.00$ 26CONSTRUCTED CONCRETE TRENCHEACH 5,500.00$ 1 0 0 0 1 5,500.00$ -$ -$ -$ 5,500.00$ 27CONNECT TO EXISTING PIPEEACH 900.00$ 1 0 0 0 1 900.00$ -$ -$ -$ 900.00$ 28FULL DEPTH RECLAMATIONSQ YD 3.00$ 0 0 480 0 480 -$ -$ 1,440.00$ -$ 1,440.00$ 29SUBGRADE PREPARATIONSQ YD 2.00$ 0 0 480 0 480 -$ -$ 960.00$ -$ 960.00$ 30ENGINEERED INFILTRATION MEDIATON 45.00$ 900 40 0 0 940 40,500.00$ 1,800.00$ -$ -$ 42,300.00$ 31AGGREGATE BASE CLASS 5TON 25.00$ 9 20 0 0 29 225.00$ 500.00$ -$ -$ 725.00$ 32BITUMINOUS MATERIAL FOR TACK COATGAL 5.00$ 2 3 34 0 39 10.00$ 15.00$ 170.00$ -$ 195.00$ 33TYPE SPWEA330C WEAR 2" THICKTON 150.00$ 5 11 127 0 143 750.00$ 1,650.00$ 19,050.00$ -$ 21,450.00$ 34STORM DRAIN INLET PROTECTIONEACH 150.00$ 0 1 0 0 1 -$ 150.00$ -$ -$ 150.00$ 35SANDY CLAY LOAM TOPSOIL BORROW (LV)CU YD 40.00$ 46 4 0 0 50 1,840.00$ 160.00$ -$ -$ 2,000.00$ 36COMPOST GRADE 2 (LV)CU YD 25.50$ 46 4 0 0 50 1,173.00$ 102.00$ -$ -$ 1,275.00$ 37TURF ESTABLISHMENTLUMP SUM 1,500.00$ 0.25 0.25 0 0 1 375.00$ 375.00$ -$ -$ 750.00$ 38SEEDING WITH MNDOT 25-151 SEED MIXTURE, FERTILIZER TYPE 3, AND CATEGORY 3N BLANKETSQ YD 2.36$ 2970 210 0 0 3180 7,010.80$ 495.71$ -$ -$ 7,506.51$ 39STREET SWEEPER (WITH PICKUP BROOM)HOUR 125.00$ 0.8 0.8 0.8 0.0 3 104.17$ 104.17$ 104.17$ -$ 312.50$ $123,225.18 $25,252.32 $22,674.17 $71,270.00 $242,421.67$12,322.52 $2,525.23 $2,267.42 $7,127.00$24,242.17$30,806.30 $6,313.08 $5,668.54 $17,817.50$60,605.42$166,360.00 $34,100.00 $30,620.00 $96,220.00 $327,270.0025% Legal; Engineering; Administrative; Fiscal CostsTotal Project CostsBLISS ADDITION STORMWATER PLANNING PROJECT - NORTH MANAGEMENT AREAEstimated Construction CostsComprehensive Estimated QuantityComprehensive Estimated Cost10% Contingency No.ItemUnit Unit PriceEnhanced Ditch Section ImprovementsBioinfiltration Basin ImprovementsTotal Quantity Enhanced Ditch Section ImprovementsBioinfiltration Basin ImprovementsTotal Cost1MOBILIZATIONLUMP SUM 3,300.00$ - -0.5 1,650.00$ 1,650.00$ 3,300.00$ 2TRAFFIC CONTROLLUMP SUM 500.00$ - -0.5 250.00$ 250.00$ 500.00$ 3CLEARINGTREE 150.00$ 2.5 2.5 5 375.00$ 375.00$ 750.00$ 4GRUBBINGTREE 150.00$ 2.5 2.5 5 375.00$ 375.00$ 750.00$ 5REMOVE BITUMINOUS PAVEMENTSQ YD 5.00$ 55 0 55 273.89$ -$ 273.89$ 6COMMON EXCAVATION (EV) (P)CU YD 11.00$ 510 80 590 5,610.00$ 880.00$ 6,490.00$ 7REMOVE 12" RCP STORM SEWERLIN FT 13.00$ 71 0 71 923.00$ -$ 923.00$ 8REMOVE FLARED END SECTIONEACH 400.00$ 1 0 1 400.00$ -$ 400.00$ 96" PERFORATED HDPE PIPE DRAINLIN FT 15.00$ 1044 92 1136 15,660.00$ 1,380.00$ 17,040.00$ 1012" RC PIPE SEWER CLASS 5LIN FT 35.00$ 34 0 34 1,190.00$ -$ 1,190.00$ 1112" PERF PE PIPE DRAINLIN FT 80.00$ 0 0 0 -$ -$ -$ 12PVC VENTED CLEANOUTEACH 350.00$ 2 1 3 700.00$ 350.00$ 1,050.00$ 13PVC UNDER-DRAIN VALVE & VALVE BOXEACH 1,500.00$ 2 1 3 3,000.00$ 1,500.00$ 4,500.00$ 144' DIA STORM MH, INCL R-1642 CSTG AND HDPE ADJ RINGSEACH 3,000.00$ 0 0 0 -$ -$ -$ 154' BEEHIVE STRUCTURE W/ R4342 CASTINGEACH5,500.00$ 1 0 1 5,500.00$ -$ 5,500.00$ 16CONNECT TO EXISTING PIPEEACH 900.00$ 0 0 0 -$ -$ -$ 17ENGINEERED INFILTRATION MEDIATON 45.00$ 450 50 500 20,250.00$ 2,250.00$ 22,500.00$ 18AGGREGATE BASE CLASS 5TON 25.00$ 28 0 28 700.00$ -$ 700.00$ 19BITUMINOUS MATERIAL FOR TACK COATGAL 5.00$ 4 0 4 20.00$ -$ 20.00$ 20TYPE SPWEA330C WEAR 2" THICKTON 150.00$ 15 0 15 2,250.00$ -$ 2,250.00$ 21STORM DRAIN INLET PROTECTIONEACH 150.00$ 0 0 0 -$ -$ -$ 22SANDY CLAY LOAM TOPSOIL BORROW (LV)CU YD 40.00$ 27 3 30 1,080.00$ 120.00$ 1,200.00$ 23COMPOST GRADE 2 (LV)CU YD 25.50$ 27 3 30 688.50$ 76.50$ 765.00$ 24TURF ESTABLISHMENTLUMP SUM 1,500.00$ 0.2 0.2 0 250.00$ 250.00$ 500.00$ 25SEEDING WITH MNDOT 25-151 SEED MIXTURE, FERTILIZER TYPE 3, AND CATEGORY 3N BLANKETSQ YD 2.36$ 2010 170 2180 4,744.68$ 401.29$ 5,145.97$ 26STREET SWEEPER (WITH PICKUP BROOM)HOUR 125.00$ 2.5 0 3 312.50$ -$ 312.50$ $66,202.57 $9,857.79 $76,060.36$6,620.26 $985.78$7,606.04$16,550.64 $2,464.45$19,015.09$89,380.00 $13,310.00 $102,690.0025% Legal; Engineering; Administrative; Fiscal CostsTotal Project CostsBLISS ADDITION STORMWATER PLANNING PROJECT - SOUTH MANAGEMENT AREAComprehensive Estimated Quantity Comprehensive Estimated CostEstimated Construction Costs10% Contingency Appendix C: MIDS Output Project Information Calculator Version:Version 3: January 2017 Project Name:Bliss Addition Stormwater Planning User Name / Company Name: Date:October 22, 2019 Project Description:North Management Area Construction Permit?:No Site Information Retention Requirement (inches):1.1 Site's Zip Code:55073 Annual Rainfall (inches):31.4 Phosphorus EMC (mg/l):0.6 TSS EMC (mg/l):109 Total Site Area Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed 2.76 2.76 Impervious Area (acres) 1.44 Total Area (acres) 4.2 Site Areas Routed to BMPs Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed 2.76 2.76 Impervious Area (acres) 1.44 Total Area (acres) 4.2 Summary Information Performance Goal Requirement Performance goal volume retention requirement: 5750 ft3 Volume removed by BMPs towards performance goal: 2158 ft³ Percent volume removed towards performance goal 38 % Annual Volume and Pollutant Load Reductions Post development annual runoff volume 4.5216 acre-ft Annual runoff volume removed by BMPs: 2.6039 acre-ft Percent annual runoff volume removed: 58 % Post development annual particulate P load:4.059 lbs Annual particulate P removed by BMPs: 3.74 lbs Post development annual dissolved P load: 3.321 lbs Annual dissolved P removed by BMPs: 2.216 lbs Percent annual total phosphorus removed:81 % Post development annual TSS load: 1340.6 lbs Annual TSS removed by BMPs: 1126.9 lbs Percent annual TSS removed:84 % BMP Summary Performance Goal Summary BMP Name BMP Volume Capacity (ft3) Volume Recieved (ft3) Volume Retained (ft3) Volume Outflow (ft3) Percent Retained (%) Ditch 01 222 2160 222 1939 10 Ditch-02 88 40 40 0 100 Ditch-03 226 399 226 174 57 Ditch-04 20 330 20 310 6 Ditch-05 29 280 29 250 11 Ditch-07 168 1278 168 1110 13 Ditch-11A 216 759 216 543 28 Biobasin-1N 1446 1238 1238 0 100 Annual Volume Summary BMP Name Volume From Direct Watershed (acre-ft) Volume From Upstream BMPs (acre-ft) Volume Retained (acre-ft) Volume outflow (acre-ft) Percent Retained (%) Ditch 01 1.0715 0.2417 0.4022 0.911 31 Ditch-02 0.0742 0 0.0686 0.0056000000000000192 Ditch-03 0.4168 0 0.3173 0.0995 76 Ditch-04 0.0542 0.118 0.0356 0.1366 21 Ditch-05 0.1707 0 0.0527 0.118 31 Ditch-07 1.0692 0 0.3879 0.6813 36 Ditch-11A 0.637 0 0.368 0.269 58 Biobasin-1N 1.028 0 0.9716 0.0564 95 Particulate Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch 01 0.9618 0.03 0.8542 0.1376 86 Ditch-02 0.0666 0 0.0656 0.001 98 Ditch-03 0.3742 0 0.3563 0.0179 95 Ditch-04 0.0486 0.0212 0.0587 0.0111 84 Ditch-05 0.1533 0 0.1321 0.0212 86 Ditch-07 0.9597 0 0.8374 0.1223 87 Ditch-11A 0.5718 0 0.5235 0.0483 92 Biobasin-1N 0.9227 0 0.9126 0.0101 99 Dissolved Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch 01 0.7869 0.1309 0.4084 0.5094 45 Ditch-02 0.0545 0 0.0512 0.0033 94 Ditch-03 0.3061 0 0.2477 0.0584 81 Ditch-04 0.0398 0.0693 0.0399 0.0692 37 Ditch-05 0.1254 0 0.0561 0.0693 45 Ditch-07 0.7852 0 0.3849 0.4003 49 Ditch-11A 0.4678 0 0.3098 0.158 66 Biobasin-1N 0.7549 0 0.7176 0.0373 95 TSS Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch 01 317.69 22.01 245.44 94.26 72 Ditch-02 21.99 0 21.32 0.669999999999998 97 Ditch-03 123.58 0 111.78 11.8 90 Ditch-04 16.06 14 20.52 9.54 68 Ditch-05 50.62 0 36.62 14 72 Ditch-07 316.99 0 236.19 80.8 75 Ditch-11A 188.87 0 156.97 31.9 83 Biobasin-1N 304.77 0 298.08 6.69 98 BMP Schematic Project Information Calculator Version:Version 3: January 2017 Project Name:Bliss Addition Stormwater Planning User Name / Company Name: Date:October 22 2019 Project Description:South Management Area Construction Permit?:No Site Information Retention Requirement (inches):1.1 Site's Zip Code:55073 Annual Rainfall (inches):31.4 Phosphorus EMC (mg/l):.6 TSS EMC (mg/l):54.5 Total Site Area Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed 1.89 1.89 Impervious Area (acres) 1.17 Total Area (acres) 3.06 Site Areas Routed to BMPs Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed 1.89 1.89 Impervious Area (acres) 1.17 Total Area (acres) 3.06 Summary Information Performance Goal Requirement Performance goal volume retention requirement: 4672 ft3 Volume removed by BMPs towards performance goal: 742 ft³ Percent volume removed towards performance goal 16 % Annual Volume and Pollutant Load Reductions Post development annual runoff volume 3.5078 acre-ft Annual runoff volume removed by BMPs: 1.1657 acre-ft Percent annual runoff volume removed: 33 % Post development annual particulate P load:3.149 lbs Annual particulate P removed by BMPs: 2.748 lbs Post development annual dissolved P load: 2.576 lbs Annual dissolved P removed by BMPs: 1.219 lbs Percent annual total phosphorus removed:69 % Post development annual TSS load: 520 lbs Annual TSS removed by BMPs: 386.2 lbs Percent annual TSS removed:74 % BMP Summary Performance Goal Summary BMP Name BMP Volume Capacity (ft3) Volume Recieved (ft3) Volume Retained (ft3) Volume Outflow (ft3) Percent Retained (%) Ditch-20 359 904 359 546 40 Ditch-18 79 2382 79 2303 3 Ditch-21 56 321 56 265 17 Ditch-22 79 280 79 201 28 Biobasin-1S 170 1797 170 1627 9 Annual Volume Summary BMP Name Volume From Direct Watershed (acre-ft) Volume From Upstream BMPs (acre-ft) Volume Retained (acre-ft) Volume outflow (acre-ft) Percent Retained (%) Ditch-20 0.4333 0.0883 0.37 0.1516 71 Ditch-18 1.2976 0.1516 0.1829 1.2663 13 Ditch-21 0.0812 0.0765 0.0694 0.0883 44 Ditch-22 0.1896 0 0.1131 0.0765 60 Biobasin-1S 1.506 0 0.4302 1.0758 29 Particulate Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch-20 0.3889 0.0097 0.3754 0.0232 94 Ditch-18 1.1647 0.0232 0.9803 0.2076 83 Ditch-21 0.0729 0.0137 0.0769 0.0097 89 Ditch-22 0.1702 0 0.1565 0.0137 92 Biobasin-1S 1.3518 0 1.1587 0.1931 86 Dissolved Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch-20 0.3182 0.0468 0.2801 0.0849 77 Ditch-18 0.953 0.0849 0.3124 0.7255 30 Ditch-21 0.0597 0.0449 0.0578 0.0468 55 Ditch-22 0.1392 0 0.0943 0.0449 68 Biobasin-1S 1.106 0 0.474 0.632 43 TSS Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) Ditch-20 64.24 3.71 60.05 7.89999999999999 88 Ditch-18 192.36 7.89999999999999130.27 69.99 65 Ditch-21 12.04 4.53 12.86 3.71 78 Ditch-22 28.1 0 23.57 4.53 84 Biobasin-1S 223.25 0 159.46 63.79 71 BMP Schematic Appendix D: Comprehensive Surface and Infiltration Volume Comparison Table Area Runoff Location Area (ac) Runoff (in)Runoff Volume (cf)Existing Surface Storage Volume (cf)BMP Type BMP Length (ft) BMP Width (ft) BMP Area (sf)BMP Media Depth (ft)Proposed Surface Storage Volume (cf)Soil Void Volume (cf)Proposed Storage Volume (cf)DITCH-01 0.70 0.44 1108 720 Enhanced Infiltration Ditch 105 8 836.48 2.5 1615 627 2242DITCH-02 0.12 0.24 105 19 Enhanced Infiltration Ditch 62 8 498.40 2.5 202 374 575DITCH-03 0.51 0.74 1370 219 Enhanced Infiltration Ditch 142 8 1136.00 2.5 1154 852 2006DITCH-04 0.04 0.70 102 8 Enhanced Infiltration Ditch 25 4 101.68 2.5 89 76 165DITCH-05 0.10 1.22 443 24 Enhanced Infiltration Ditch 37 4 148.40 2.5 316 111 427DITCH-06 0.03 1.37 149 27 Existing Ditch 0 0 0.00 0.0 27 0 27SUBTOTAL 1.50 4.71 3276 1017371 2721 3402 2041 5442DITCH-07 1.24 0.55 2476 886 Enhanced Infiltration Ditch 105 8 840 2.5 1612 630 2242DITCH-08 0.23 0.09 75 414 Existing Ditch N/A N/A 0 0.0 1008 0 1008DITCH-09 0.33 0.42 503 953 Existing Ditch N/A N/A 0 0.0 1311 0 1311DITCH-10 0.28 0.42 427 173 Existing Ditch N/A N/A 0 0.0 505 0 505DITCH-11A 0.64 0.42 972 52 Enhanced Infiltration Ditch 271 4 1082 2.5 708 812 1520SUBTOTAL 2.72 1.90 4453 2478376 1923 5144 1442 6585BIOBASIN-1N 0.86 0.60 1873 0 Bioinfiltration Basin N/A N/A 253 2.0 2136 190 2325SUBTOTAL 0.86 0.60 1873 00 253 2136 190 2325OVERALL TOTAL 5.08 7.21 9602 3495747 4897 10681 3672 14353DITCH-12 3.57 0.44 5702 8261 Existing Ditch N/A N/A 0 0.0 8261 0 8261DITCH-13 0.09 1.98 647 86 Existing Ditch N/A N/A 0 0.0 86 0 86DITCH-14 0.11 1.99 795 465 Existing Ditch N/A N/A 0 0.0 465 0 465SUBTOTAL 3.77 4.41 7143 88120 0 8812 0 8812DITCH-15 0.16 0.52 302 183 Existing Ditch N/A N/A 0 0.0 183 0 183DITCH-16 2.90 0.46 4842 2579 Existing Ditch N/A N/A 0 0.0 2579 0 2579SUBTOTAL 3.06 0.98 5144 27620 0 2762 0 2762BIOBASIN-1S 0.45 0.74 1200 17 Bioinfiltration Basin N/A N/A 300 2.0 1666 180 1846DITCH-19 0.04 0.73 106 338 Existing Ditch N/A N/A 0 0.0 338 0 338DITCH-20 0.33 0.81 970 192 Enhanced Infiltration Ditch 146 8 1166 2.5 552 874 1426DITCH-21 0.07 0.78 198 656 Enhanced Infiltration Ditch 48 4 193 2.5 765 145 910DITCH-22 0.13 0.80 378 72 Enhanced Infiltration Ditch 75 4 300 2.5 186 225 411SUBTOTAL 1.02 3.86 2852 1274269 1959 3506 1424 4931DITCH-23 0.61 0.32 709 1490 Existing Ditch N/A N/A 0 0.0 1730 0 1730DITCH-24 0.17 0.81 500 1 Existing Ditch N/A N/A 0 0.0 1 0 1DITCH-25 0.95 0.24 828 12377 Existing Ditch N/A N/A 0 0.0 12950 0 12950SUBTOTAL 1.73 1.37 2036 138680 0 14681 0 14681DITCH-26 0.07 0.78 198 1193 Existing Ditch N/A N/A 0 0.0 1193 0 1193DITCH-27 0.39 0.49 694 404 Existing Ditch N/A N/A 0 0.0 405 0 405DITCH-28 0.58 0.49 1032 261 Existing Ditch N/A N/A 0 0.0 261 0 261DITCH-29 0.22 0.49 391 27 Existing Ditch N/A N/A 0 0.0 227 0 227DITCH-30 0.66 0.49 1174 1045 Existing Ditch N/A N/A 0 0.0 1976 0 1976DITCH-31 1.51 0.49 2686 31 Enhanced Infiltration Ditch 161 4 642 2.5 60 482 542SUBTOTAL 3.43 3.23 6175 2961161 642 4122 482 4603OVERALL TOTAL 13.01 13.85 23351 29678429 2601 33884 1906 35789NORTH MANAGEMENT AREASOUTH MANAGEMENT AREA 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