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HomeMy WebLinkAboutStudies APPLICANT 6/1/2020Stormwater Study for South Hills 411 Level Reservoir City of Springfield, Oregon OWNER: Springfield Utility Board 202 South 18" Street Springfield, OR 97477 Steven Wages, PE Phone: (541) 744-3728, Email: StevenW@subutil.com ENGINEER: Murraysmith 888 SW 5th Avenue, Suite 1170 Portland, OR 97204 Justin Ford, PE Phone: (503) 225-9010, Email: Justin.Ford@murraysmith.us PROJECT LOCATION: Assessor's Map No: 18-02-03-10 Tax Lot No: 00100 No site address Located on South 6611 Place Springfield, OR 97478 SUBMITTAL DATE: April 2020 Table of Contents 1. Project Narrative 1.1 Project Overview........................................................................................................... 1 1.2 Requirements Summary ................................................................................................1 1.3 Proposed Stormwater System Overview....................................................................... 2 1.4 Reservoir Emergency Overflow and Periodic Maintenance Cleaning ........................... 3 2. Hydrologic and Hydraulic Calculations 2.1 Calculations Overview...................................................................................................4 2.2 Pre -Development Site Characterization........................................................................ 4 2.3 Post -Development Site Characterization...................................................................... 5 2.4 Design Storm................................................................................................................. 6 2.5 System Capacity............................................................................................................7 2.6 Conclusion.....................................................................................................................7 Figures 1 Stormwater Study Hydrological Study Map.................................................................. 8 2-1 Post -Development Pervious and Impervious Areas......................................................9 2-2 Post -Development Surfaces........................................................................................ 10 Appendices A City of Springfield Stormwater Management System Scope of Work ........................ A-1 B NCRS Soil Classification Map...................................................................................... 3-1 C HydroCAD Output Report for 2 -Year Storm Event for Pre -Development Conditions.................................................................................................................. C-1 D HydroCAD Output Report for 2 -Year Storm Event for Post -Development Conditions.................................................................................................................. D-1 E HydroCAD Output Report for 25 -Year Storm Event for Post -Development Conditions.................................................................................................................. E-1 F Level Spreader and Riprap Sizing Calculations........................................................... F-1 19-2621 Page i Stormwater Study April 2020 SUB South Hills 4th Level Reservoir Section 1 Project Narrative 1.1 Project Overview The proposed South Hills 4th Level Reservoir Project is a drinking water storage reservoir that will be owned by the Springfield Utility Board (SUB) and located in the City of Springfield. The project site is located on property owned by SUB (Map 18-02-03-10, Lot 100) at the southerly end of South 6611 Place, at Jessica Drive, in the Thurston Hills area of Springfield. The project site is currently vacant, forested land. The project includes construction of a 50 -foot diameter steel water storage tank and associated piping and valving. Other site improvements include site grading, stormwater management facilities, site access road, a small telemetry building, and surface restoration. 1.2 Requirements Summary The City of Springfield's stormwater quality and capacity design standards are outlined in Chapters 3 and 4 ofthe City's Engineering Design Standards and Procedures Manual (EDSPM). AStormwater Management System Scope of Work completed by the City on February 3rd, 2020 further details the stormwater requirements for this project and has been included as AppendlxA. A Hydrological Study Map, as required by Chapter 4 of the EDSPM, has been provided as FIgUre 1 of this report. The project qualifies for a Small Site Stormwater Study, for which the Rational Peak Flow Method is accepted. Calculations must show system capacity for a 2 -year storm event and overflow effects of a 25-yearstorm event. Time of concentration shall be determined using a 10 -minute starttime. Additional requirements include a sediment filtration system to protect downstream facilities. Forthis project, water quality calculations and a downstream drainage analysis are not required. 1.3 Proposed Stormwater System Overview The reservoir site is located at the top of a hill with a maximum elevation of 1,120 feet and a minimum elevation of 960 feet in the northwestern most region of the property. The hill's apex occurs along the southern property line near the center. The site generally slopes away from the summit in all directions at 25 to 35 percent, with slopes exceeding 50 percent in the northeast area of the site. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS), on-site soils types are Dixonville silt clay loam (41F) and Witzel very cobbly loam (138E). Both soils have a hydrologic soil group (HSG) of D. The proposed site gradingwill generally maintain the existing site topography, with most proposed site grading 19-2621 Page 1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir occurring in order to accommodate the proposed access road. The project will disturb approximately 1.9 acres of the 11 -acre property. All on-site non -building rooftop (NBR) impervious area runoff will be collected, conveyed, and treated through a series of ditches such that no runoff from impervious areas discharges onto adjacent properties. Runoff from the compacted gravel access road will either discharge onto native, forested land or be conveyed to the City of Springfield public stormwater system byway of ditchesto an existing City catch basin. The project will implement a collection system that routes all stormwater from the reservoir and telemetry building roofs and potable water from reservoir drain and overflow pipes to an on-site manhole. From the manhole, runoff will be conveyed to a ditch and level spreader system. The level spreaderwill discharge into undisturbed, forested area. Forested areas north and east of the finished project impervious areas will continue to runoff downhill to the north, consistent with the predevelopment condition. Some of the undisturbed on-site pervious area runoff will be collected in the ditches. The net forested area runoff across property lineswill be reduced compared to existing conditions. Once construction has ended, disturbed pervious areas will be seeded with grass. The gravel and grassy areas will be graded away from reservoir foundations and continue to runoff downhill towards forested areas, consistent with the predevelopment conditions. The existing forest is expected to slow, filter, and infiltrate a portion of the runoff from the project site. The Hydrological Study Map depicts the sub -basins that make up the finished site. Sub -Basin 1 includesthe lower portion of the gravel access road and a large portion of undisturbed forested area. This sub -basin will drain to a 568 -foot ditch adjacent to the east side of the road. This ditch will discharge to a catch basin with a sediment trap which will tie into the City of Springfield stormwater system byway of existing stormwater piping that terminates at the south end of South 66th Place. Sub -Basin 2 includesthe upper portion ofthe access road and the southern half ofthe reservoir site. A523 -foot ditch adjacent to the south of the access road and a 65 -foot ditch south of the reservoir site will collect runoff from the gravel surfaces in Sub -Basin 2. The 523 -foot ditch will convey water downhill to the west and discharge into the forest and the 65 -foot ditch will convey water to the northeast and discharge into forested area. Sub -Basin 3 includesthe northern half ofthe reservoirsite, aswell asthe reservoir French drain, reservoir overflow and drain piping, telemetry building roof drain, and vault floor drain, which will all be piped to Manhole 1. This manhole will be piped to a level spreader for dispersing flows onto native forested land. Surface runoff will drain to a 94 -foot ditch adjacent to the north of the access road leading to the level spreader. 60% Design Plan sheets have been submitted with the City of Springfield Land Use Application. Sheet C-4 shows the off-site access road grading plan, including the 523 -foot and a 568 -foot roadside ditches. Sheet C-6 illustratesthe on-site piping and drainage plan. The level spreader plan and details are shown on Sheet C-11 and the ditch cross sections are illustrated on Sheet C-12. 19-2621 Page 2 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir 1.4 Reservoir Emergency Overflow and Periodic Maintenance Cleaning The proposed reservoir facilitywill not generate wastewater as part of its operation. However, the reservoir will be equipped with a drain and an overflow discharge pipe in the unlikely event that an emergency overflow occurs. To minimize the potential for emergency overflows, the reservoir and the pumping facilities which feed the reservoir will be equipped with telemetry and control logic connected tot he water system's existing electronic facility monitoring and control features. Analarm will be triggered prior to discharge of water. Should there be a problem with receiving or responding to the alarm to prevent an overflow, the on-site storm drainage pipes are sized to adequately accommodate the maximum reservoir overflow rate of 1.8 cfs. The overflow discharge will be dispersed over forested land by means of riprap lined basin and level spreader, which will dissipate energy and control flow, until operations personnel can respond to the event by turning off associated pumps. On a frequency of approximately once every 5 years, the reservoir will be taken off-line and emptied for inspection and maintenance. As much as possible, the water in the reservoir will be conveyed back into the drinking water distribution system. The remaining water will be drained through the on-site drainage system and flow rate will be monitored to avoid downstream impacts. The reservoir drain pipe will penetrate the reservoir floor and extend to Manhole 1, where reservoirdrain flowswill combinewith roof runoff and floordrain flows. The manhole will be piped to the level spreader where flows will be dispersed over native forested land. 19-2621 Page 3 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir Section 2 Hydrologic and Hydraulic Calculations 2.1 Calculations Overview This project qualifies for Small Site Stormwater Study thus, the Rational Peak Flow Method was used to model site runoff. Figure 2-1 and Figure 2-2 show the post -development conditions by surface type (imperviousor pervious) and bytype of land cover (forest, seeding, gravel, pavement, and roofs). A pre -development map is not shown because the entire site is currently pervious, forested land. Figure 2-1 shows pervious areas, non -building rooftop impervious surfaces, and building rooftop impervious surfaces post -development. Figure 2-2 shows the different surface materials, which correspond to the runoff coefficient, C, used for the Rational Method. For the purposes of the runoff modeling, the site has been divided into three sub-basinswhich represent the areas which will contribute to the post -development stormwater management system of ditches, piping, and the level spreader. Sub -Basin 1 drains to the 568 -foot ditch located adjacent to the east side of the road. Sub -Basin 2 drains to the 523 -foot ditch located adjacent to the south side of the road and the 65 -foot ditch south of the reservoir site. Flows to the 65 -foot ditch will be minimal, so all runoff was assumed to drain to the 523 -foot ditch for modelling purposes. Sub - Basin 3 drains to the 94 -foot ditch northwest of the reservoir site. 2.2 Pre -Development Site Characterization The site soils are classified bythe USDA NRCS as Dixonville silt clay loam with 30-50% slopes in HSG D and Witzel very cobbly loam at 3-30% slopes in HSG D. The NRCS site soil data is included in Appendlx l All soil groups were assumed to be HSG D in the runoff models. The pre -development site consists of forested land on an approximately 11 -acre parcel. Much of the site will be left undisturbed and stormwaterwill continueto runoff as it did in pre -development conditions. The unoccupied land cover is represented bya runoff coefficient, C, of 79. The project site varies in slope from about a 5% slope in the center to 30% slopes in the west and 60% in the east. The pre -development surfaces and associated runoff coefficient used in the runoff models are shown in Table 2-1. 19-2621 Page 4 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir Table 2-1 Pre -Development Surfaces Forest woodland& 0.20 121,725 ft' 30,210 ft' 11,425 ft' 481,835 ft' Forests, Hilly 121,725 ft' 30,210 ft' 11,425 ft' 481,835 ft' 2.3 Post -Development Site Characterization The post -development site includes a gravel access road, steel reservoir roof, small structures, and the extents of site disturbance which will be seeded areas. Small structures include the reservoir valve vault, telemetry building, and concrete. The site grading will generally maintain existing topography and the project will only disturb approximately 1.9 acres of the 11 -acre property. Impervious areas were assigned a runoff coefficient of either 0.85 or 0.90 and disturbed sloped areas were assigned a C of 0.30. The post -development surfaces and runoff coefficients used in the runoff models are represented in Table 2-2. 19-2621 Page 5 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir Table 2-2 Post -Development Surfaces Gravelaccess woodland& Forest Pavement Reservoir and Forests, Hilly Disturbed, Side Slopes, seeded area Earth Gravelaccess Gravel road Pavement Reservoir and Pavement& structures Roofs Concrete pads Pavement & and vaults Roofs 2.4 Design Storm 0.20 91,820 fP 0.30 19,555 fP 10,270 ft' 11,030 ftr 0.85 10,350 ftp 8,910 ft, 0.90 0 ftr 0 ftr 0.90 0 ftr 0 ftr 121,725 ft' 34210 ftc 0ft' 401,340 ft' 3,250 ft' 53,060 ft' 5,480 ft' 24,740 ft' 2,275 ft' 2,275 ft' 420 ft' 420 ft' 11,425 fP 481,835 ft' As specified in Section 4.03.3 of the City of Springfield EDSPM, the Intensity Duration Frequency Curves from the West Springfield Drainage Master Plan (1983) were used to determine the rainfall intensities fort he 2 -year and 25 -year, 24-hour storm events. A rainfall intensity of 2.2 -inches per hour was used for the 2 -year storm event and 2.1 -inches per hour for the 25 -year storm event. 19-2621 Page 6 Storrmveter Study April 2020 SUB South Hills 4th Level Reservoir 2.5 System Capacity The capacities of the proposed on-site facilities were analyzed for peak flow conditions using the rational method in HydroCAD for the 2 -year, 24-hour storm and 25 -year, 24-hour storm. The HydroCAD report for the 2 -year storm event for pre -development conditions can be found in Appendlx C. Sub -Basins 1 and 3 were modelled as one system in HydroCAD, with the 94 -foot ditch, 568 -foot ditch, and 12° pipe connecting intothe Cityof Springfield stormwater system. This is because the level spreader disperses runoff into Sub -Basin 1. Peak flows for the 2 -year storm event for Sub - Basin 3 and the 94 -foot ditch were 0.23 cubic feet per second (cfs). Peak flows for Sub -Basin 1 were 0.91 cfs and 1.14 cfs in the 568 -foot ditch and the 12° pipe. Sub -Basin 2 drains to the 523 - foot ditch which then disperses water into the adjacent forested area. Peak flows from Sub -Basin 2 and the 523 -foot ditch are 0.36 cfs. The HydroCAD report for the 2 -year storm for post - development conditions can be found in Appendix D. Peak flows for the 25 -year event did not exceed ditch and piping capacities. Peak flows forthe 2 - year and 25 -year storms are shown in Table 2-3. Further details can be found in the HydroCAD report in Appendix E. Table 2-3 Peak Flows 2.6 Conclusion The reservoir project's stormwater management system has the capacity to convey and control flow from the post -developed 2 -year and 25yearstorms such that runoff flows onto neighboring sites are not increased. The downstream pipe connecting to the City of Springfield stormwater system has shown to have adequate capacity for the 2 -year and 25 -year storm events. Calculations pertinent to the level spreader length and riprap sizing can be found in AppendxF. 19-2621 Page 7 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir // rU %_ //i' ' r\� \\\\\\\\ \\\ — \✓ 9 LEGEND • • SUB-Bw IN BOUNDARY DROI CENTERLINE MENT TRAY DIRECTION OF FLOW RUNSSEDIMEM S% \\ \\\�— \ �"� / /// / / ✓ / / /////i/ / / vvvvwv� wvvvw� AAAA vvv MEW/ o LEVEL P / //// /////////FAU- SOB-BASIN 3. � — 4y Springfield Utility Board South Hills 4th Level Reservoir Stormwater Study - Hydrological Study Map 1 523' DITCH 65' DITCH / 1HIGHWINT HIGHPoINT / February 2020 & I � s '° 20 0 40 ED murraysmith, O SCALEINFEET V N 1 � 90 20 0 90 w SCALE IN FEET LEGEND PE0.VIWSSORFACE NON -BUILDING RW70PIMPERWMS SURFACE BUILDING ROOFTOP IMPERVIWSSURFACE LEGEND acaEs '&Mff \� _ o.zBs acaEs FIGURE 2-2 Springfield Utility Board South Hills 4th Level Reservoir Post-Development Surfaces N I / February 2020 I � s '� , ' murraysmith, SC EINFEU ' I � V Appendix A City of Springfield Stormwater Management System Scope of Work 19-2621 Page A-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir DEVELOPMENT AND PUBLIC WORKS SPRINGP 225 FIFTH STREET OREGON SPRINGFIELD, OR 97477 PHONE: 547.726.375353 FAX: 541.726.1021 www. springfield-orgov STORMWATER MANAGEMENT SYSTEM SCOPE OF WORK --------------------------------- (Area below this line filled out by Applicant) --------------------------------- (Please return to Clayton McEaehern @ City afSprineeld Development and Public Works; Fax # 7361021, Phone # 7361036), email: cmeeachern@springfield-orgov Project Name: South Hills 4" Level Reservoir Applicant: Springfield Utility Board (c/o Murraysmith) Assessors Parcel #: 18-02-03-10-00100 Date: 02/03/2020 Land Use(s): Public utilities Phone #: (503) 225-9010 Project Size (Acres): 1.9 acres Fax #: (At a minimum, all boxes checked by the City on the front and back ofthis sheet shall be submitted Approx. Impervious Area: 24,175 square feet Email: Justin.Ford@Murraysmith.us Project Description (Include a copy of Assessor's map): Construction of a water storage reservoir with associated access road and piping, which includes 2,645 SF of non -pollutant generating impervious surfaces (2,125 SF steel reservoir roof and miscellaneous concrete surfaces) and 21,530 SF of compacted gravel surfacing. Drainage Proposal (Public connection(s), discharge location(s), etc. Attach additional sheet(s) if necessary: Route tank roof runoff and tank drain/overflow to manhole. Route manhole to outlet in forest (NW of site, away from landslide area) with a level spreader for overland dispersion. Collect site runoff in ditches and discharge to forest. Collet road runoff in roadside ditch. Collect runoff at bottom of hill in ditch inlet, route to proposed catch basin with sediment separator in street, and route to existing City stortnwater system in S 66'" Place. Proposed Stormwater Best Management Practices: Sediment fencing, gravel construction entrance, slope matting, plastic sheeting, erosion control seeding, level spreader, sediment separators -------- ------ (Area below this line tilled out by the City and Returned to the Applicant) (At a minimum, all boxes checked by the City on the front and back ofthis sheet shall be submitted or an a lication to be complete for submitral, although other requirements mar be necessary) Drainaee Study Type (EDSPM Section 4.03.2): (Note, UH may be substituted for Rational Method) N Small Site Study — (use Rational Method for calculations) ❑ Mid -Level Development Study — (use Unit Hydrograph Method for calculations) ❑ Full Drainage Development Study — (use Unit Hydrograph Method for calculations) Environmental Considerations:: ❑ Wellhead Zone: j./l A dHillside Development: ❑ Wetland/Riparian: ❑ Floodway/Floodplain: t,4A ❑ Soil Type:3Xy% E]Other Jurisdictions Ajit. Downstream Analysis: 41 i'Oirv00116 N N/A ❑ Flow line for starting water surface elevation: ❑ Design HGL to use for starting water surface elevation: ❑ Manhole/Junetion to take analysis to: Return to Clayton McEachern @ City of Springfield, email: cmceachern@springfield-o ,gov, FAX: (541) 736-1021 COMPLETE STUDY ITEMS * Based upon the information provided on the front of this sheet, the following represents am hummon of what is needed for an application to be complete for submittal with respect to drainage; however, this list should not be used in lieu of the Springfield Development Code (SDC) or the Cio) 's Engineering Design Manual. Compliance with these requirements does not constitute site approval, Additional site specific information may be required. Note: Upon scoping sheet submittal, ensure completed fmvn has been signed in the space provided below: Interim Desi n Standards/Water Quality (EDSPM Cha ter3 Req'd N/A ❑ All non -building rooftop (NBR) impervious surfaces shall be pre-treated (e.g. multi-chambered catchbasin w/oil filtration media) for stormwater quality. Additionally, a minimum of 50% of the NBR impervious surface shall be treated by vegetated methods. -',S;px air to •6iok P7'yrr4 o n 4/nt smile u�- Ma.sr,6,A 5,,,4a ® ❑ Where required, vegetative stormwater design shall be consistent with design standards (EDSPM Section 3.02), set forth in Chapter 2 of the Eugene Stormwater Management Manual. i4l F-] For new NBR impervious area less than 15,000 square feet, a simplified design approach may be followed as specified `Y by the Eugene Stormwater Management Manual (Sec2A.1). ® El If a stormwater treatment swale is proposed, submit calculations/specifications for sizing, velocity, flow, side slopes, bottom slope, and seed mix consistent with City of Springfield or Eugene's Stomtwater Management Manual. ❑ ® Water Quality calculations as required in Section 3.03.1 of the EDSPM. rA F-] All building rooftop mounted equipment, or other fluid containing equipment located outside of the building, shall ® ❑ Drainage study prepared by a Professional Civil Engineer licensed in the state of Oregon. © ❑ A complete drainage study, as required in EDSPM Section 4.03.1, including a hydrological study map. ® ❑ Calculations showing system capacity for a 2 -year storm event and overflow effects of a 25 -year storm event. M F7 The time of concentration (Tc) shall be determined using a 10 minute start time for developed basins. Private stormwater easements shall be clearly depicted on plans when private stomuwater flows from one property to another. Drywclls shall not receive runoff from any surface w/o being treated by one or more BMPs, with the exception of residential building roofs (EDSP Section 3.03.4.A). Additional provisions apply to this as required by the DEQ. Refer to the wcbsitc: hood/unvw.deg.state.or.us/wq/uic/uic.htm for more information. —To Ally+i'Nn h 0 d til d here ❑ ® Detention ponds shall be designed to limit runoff to pre -development rates for the 2 through 25 -year storm events. *This form shall be included as an attachment, inside the front cover, of the stormwater study. * IMPORTANT: ENGINEER PLEASE READ BELOWAND SIGN! As the engineer of record, I hereby certify the above required items are complete and included with the submitted stormwater study and plan set. Signature Date Form Version 5: June 2015 A downstream drainage analysis as described in EDSPM Section 4.03A.C. On-site drainage shall be governed by the Oregon Plumbing Specialty Code (OPSC). ❑ © Elevations of the HGL and flow lines for both city and private systems where applicable. ❑ Design of Stoma Systems (EDSPM Section 4.04). ® ❑ Flow lines, slopes, rim elevations, pipe type and sizes clearly indicated on the plan set. ❑ Minimum pipe cover shall be 18 inches for reinforced pipe and 36 inches for plain concrete and plastic pipe materials, or proper engineering calculations shall be provided when less. The cover shall be sufficient to support an 80,000 Ib load without failure of the pipe structure. Meaning's "n" values for pipes shall be consistent with Table 4-1 of the EDSP. All storm pipes shall be designed to achieve a minimum velocity of three 3 Feet per second at 0.5 pipe full based on Table 4-1 as well. Other/Miseellaneous ® Existing and proposed contours, located at one foot interval. Include spot elevations and site grades showing how site drains. Private stormwater easements shall be clearly depicted on plans when private stomuwater flows from one property to another. Drywclls shall not receive runoff from any surface w/o being treated by one or more BMPs, with the exception of residential building roofs (EDSP Section 3.03.4.A). Additional provisions apply to this as required by the DEQ. Refer to the wcbsitc: hood/unvw.deg.state.or.us/wq/uic/uic.htm for more information. —To Ally+i'Nn h 0 d til d here ❑ ® Detention ponds shall be designed to limit runoff to pre -development rates for the 2 through 25 -year storm events. *This form shall be included as an attachment, inside the front cover, of the stormwater study. * IMPORTANT: ENGINEER PLEASE READ BELOWAND SIGN! As the engineer of record, I hereby certify the above required items are complete and included with the submitted stormwater study and plan set. Signature Date Form Version 5: June 2015 Appendix B NRCS Soil Map 19-2621 Page B-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir M 212 N m1.N WS l Map—Lane County Area, Oregon (SUB Gh Level Reservoir Prged Sle) ti w aarm mmm Harm ammo smm mrzo spm smam v�sm vim svrmo a MV 5a6:1:4,900 Rpm on A bn6aPe(11"x S.S)sM1ui. p Nms a m m mo AMap, �� ���� � ElgebsUTNZe1ON� LiNatural Resources IM1Fb Sol Survey 2/12/2020 Conservation Serme National Cooperative S lSurvey Pagel of Soil Map—Lane County Area, Oregon (SUB Gh Level Reservoir Project Sde) _SD, Natural Resources web Sol Survey 211212929 all Conservation Service National Cooperative Shc Survey Page 2 of 3 MAP LEGEND MAP INFORMATION Area at Were. tA09 Spoil Area The sal surveys that comprise your AOl were mapped at Area of Interest(AOI) 1:20,898. Q Stany Spat Soils Very Sony Spa Waming: Soil Map may not be vapid al Mrs scale. 0 Soil Map Unit Polygons 9 VJrf Spot p Enlargement of maps beyond the scale of mapping can cause ,.,. Soil Map Unic Lines misunderslantling of the tletail of mapping and accuracy of soil 4 Other line placement. The maps do not show the small areas of Soil Map Unit Points soils that could have been shown at a more detailed Special Line Feelcontrasting Special Point Features scale. Lg Blowout water Features Streams and Canals Please rely on the bar scale on each map sheet for map ® Boraw Pit measurements. Trenspartatian Clay Spot Rails Source of Map: Natural Resources Conservation Service 0 Closed Depression Web Soil SurveyLIRL: Interstate Highways Coordinate System: web Mercator(EPSG:3B5]) Gravel Pit US Routes Maps from the Web Soil Survey are based on the Web Mercator Gravely Spa Malor Roads projection, which preserves and shape but schdistorts and area, projection that preserves area, such as the ion that ® Landfill Local Roads Abersdistance o Albers equal-area conic projection, should be used if more Lara Flaw accurate calculations of distance or area are req uired, Background aga Marsh or swamp . Aerial Photography This product is generated from the USDA­gRCS certified data as of Ne version dates) listed below * Mine or Query Soil Survey Area: Lane County Area, ® Miscellaneous Ydscer ep10, 2019 Survey Area Data: Version 16, Sep 10, 2019 ® Perennial VMmer Shc map units are labeled (as space allows) for map scales y, Rock Outcrop 1:5D,WD or larger. A Saline Spot Dates) aerial images were photographed: Jun 12, 20191 19, 2019 Sandy Spot The odhophoto or other base map on which the soil lines were Severely Eroded Spot compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor Sinkhole shifting ofmap and boundaries may be evident. �p Slide or Slip Sodic Spot _SD, Natural Resources web Sol Survey 211212929 all Conservation Service National Cooperative Shc Survey Page 2 of 3 Sal Map�ane Cmdy Area, Oregon Map Unit Legend SUB 4 Levin Reservoir Project Site LSD4 Natural Resources Web Soil Survey 2/1212020 iMi Conservation Service National Cooperatirve Soil Survey Page 3 of3 Map Uril Sjmibd Map Uril Name Acres in AOI Percent of AOI 41E Dixonvile silty clay barn, 12 to W percent sicpes 38.5 31.4% 41F Dixonvile silty clay bam, 3010 50 percent sicpes MA 18.2% 89C Nelda silly day loam, 21012 percent sicpes 0.0 0.0% 89D Nekia sity day loam, 12 to 20 percent sicpes 5.8 4.8% 113E Ribier cobbly silty clay loam, 1210 30 percent sicpes 14.8 11.0% 138E Wiml very cobbly loam, 310 W percent slopes MA 21.0% 1380 Wiml very cobbly loam, 3010 75 percent slopes 15.8 12.0% Tarek far Area of i tereal 1228 100.0% LSD4 Natural Resources Web Soil Survey 2/1212020 iMi Conservation Service National Cooperatirve Soil Survey Page 3 of3 Map Unit Description: Dixorrolle silty clay loam, 30 to 50 percent slopes—Lane County Area.. SUB 4th Level Reservoir Project Site Oregon Lane County Area, Oregon 41 F—Dixonville silty clay loam, 30 to 50 percent slopes Map Unit Setting National map unit symbol. 236v Elevation. 350 to 1,800 feet Mean annual precipitation: 40 to 60 inches Mean annual air temperature: 48 to 54 degrees F Frost -free period. 165 to 210 days Farmland classification. Not prime farmland Map Unit Composition Dixonville and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Dixonville Setting Landform: Low hills, low hills Landform position (two-dimensional): Backslope, shoulder Landform position (three-dimensional): Side slope, nose slope Down-slope shape: Linear Across -slope shape: Linear Parent material. Colluvium and residuum derived from basalt Typical profile H1 - 0 to 14 inches. silty clay loam H2 - 14 to 26 inches: silty clay H3 - 26 to 36 inches: weathered bedrock Properties and qualities Slope: 30 to 50 percent Depth to restrictive feature: 20 to 40 inches to paralithic bedrock Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0. 06 to 0.20 in/hr) Depth to water table: More than 80 inches Fraquencyoffloodirg: None Fmquencyofpondirg: None Available water storage in profile: Low (about 4.6 inches) Interpretive groups Lard capability classification (irrigated): None specified Lard capability classification (nonirrigated): 6e Hydrologic Soil Group: D LSDA Natural Resources Web Soil Survey 2/1212020 iil conservation Serves National Cooperative Soil Survey Page 1 ort Map Unit Description: Dixonville silty clay loam, W to 50 percent slopes --Lane County Area, SUB 4th Level Reservoir Project Site Oregon Hydric soil mting. No Data Source Information Soil Survey Area: Lane County Area, Oregon Survey Area Data: Version 16, Sep 10, 2019 LSDA Natural Resources Web Soil Survey 2/1212020 iil Conservation Serme National Cooperative Soil Survey Page 2 oft Map Unit Description: WAzel very cobbly loam, 3 to 3D percent slopes --Lane County Area.. SUB 4th Level Reservoir Project Site Oregon Lane County Area, Oregon 138E—Witzel very cobbly loam, 3 to 30 percent slopes Map Unit Setting National map unit symbol. 2354 Elevation. 300 to 1,500 feet Mean annual precipitation: 40 to 60 inches Mean annual air temperature: 50 to 54 degrees F Frost -free period. 165 to 210 days Farmland classification. Not prime farmland Map Unit Composition Wetzel and similar sails. 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Witzel Setting Landform: Hills Landform position (two-dimensional): Summit, shoulder Landform position (three-dimensional): Interfluve, nose slope Down-slope shape: Linear Across -slope shape: Linear Parent material. Colluvium and residuum derived from basic igneous rock Typical profile Hl - 0 to 4 inches: very cobbly loam 1-12-4tol7inches. very cobbly clay loam 1-13- 17to 21 inches: unweathered bedrock Properties and qualities Slope: 3 to 30 percent Depth to restrictive feature: 12 to 20 inches to lithic bedrock Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequencyofflooding: None Frequencyofponding. None Available water storage in profile: Very low (about 1.1 inches) Interpretive groups Lard capability classification (irrigated): None specified Lard capability classification (nonirrigated): 6s Hydrologic Sail Group: D Forage suitability group: Well Drained > 15% Slopes (GO02XY0010R) LSDA Natural Resources Web Soil Survey 2/1212020 i Conservation Serves National Cooperative Soil Survey Page 1 ort Map Unit Description: Wrizel very cobbly loam, 3 to 30 percent slopes --Lane County Area, SUB 4th Level Reservoir Project Site Oregon Hydric soil rating: No Data Source Information Soil Survey Area: Lane County Area, Oregon Survey Area Data: Version 16, Sep 10, 2019 LSDA Natural Resources Web Soil Survey 2/1212020 i Conservation Serme National Cooperative Soil Survey Page 2 oft Appendix C HydroCAD Output Report for 2 -Year Storm Event for Pre -Development Conditions 132621 Page C-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir 12R On -Site Fores 11R On -Site Forest On -Site F Sub -Basin 2 Subcat Reach m Link Sub -Basin 1 ore t 1S Sub -Basin 3 (Res Site) Prepared by {enter your company name he Area Listing (all nodes) Area C Description (acres) (subcatchm ent-numbers) 3.488 0.20 Woodland & Forests, Hilly (8S, 10S) 0.282 0.20 Woodlands & Forests, Hilly (1 S) 3.750 0.20 TOTAL AREA Printed 2/192020 Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 3 Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by Rational method, Rise/Fall=1.0/1.0 xTc Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Sub -Basin 3 (Res Site) Runoff Area=11,425 sf 0.00% Impervious Runoff Depth>5.74" Flow Length=150' Slope=0.1000'/' Tc=10.0 min C=0.20 Runoff=0.08 cfs 0.125 of Subcatchment BS: Sub -Basin 1 Runoff Area=121,725 sf 0.00% Impervious Runoff Depth>5.74" Flow Length=500' Slope=0.3000'/' Tc=10.0 min C=0.20 Runoff=0.88 cfs 1.337 of Subcatchment 105: Sub -Basin 2 Runoff Area=30,210 sf 0.00% Impervious Runoff Depth>5.74" Flow Length=250' Slope=0.3000'/' Tc=10.0 min C=0.20 Runoff=0.17 cfs 0.332 of Reach 11 R: On -Site Forest Avg. Flow Depth=0.07' Max Vel=0.20 fps Inflovr--0.88 cfs 1.337 of n=0.400 L=100.0' 5=0.1000'/' Capacity=1.28 cfs Outflow=0.88 cfs 1.321 of Reach 12R: On -Site Forest Avg. Flow Depth=0.05' Max Vel=0.18 fps Inflovr--0.17 cfs 0.332 of n=0.400 L=100.0' 5=0.1000'/' Capacity=0.50 cfs Outflow=0.17 cfs 0.327 of Reach 13R: On -Site Forest Avg. Flow Depth=0.03' Max Vel=0.11 fps Inflovr--0.08 cfs 0.125 of n=0.400 L=100.0' 5=0.1000'/' Capacity=0.50 cfs Outflow=0.08 cfs 0.123 of Total Runoff Area = 3.750 ac Runoff Volume =1.794 of Average Runoff Depth = 5.74" 100.00% Pervious= 3.750 ac 0.00% Impervious = 0.000 ac Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydnoCAD Software Solutions LLC Paae 4 Summary for Subcatchment 1S: Sub -Basin 3 (Res Site) Runoff = 0.06 cfs @ 0.17 hrs, Volume= 0.125 af, Depth> 5.74" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 0 0.90 Pavement & Roofs 0 0.85 Gravel Pavement 11,425 0.20 Woodlands & Forests, Hilly 0 0.30 Side Slopes, Earth 0 0.90 Pavement & Roofs 11,425 0.20 Weighted Average 11,425 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 150 0.1000 1.58 Shallow Concentrated Flow, Forest 1.6 150 Total, Increased to minimum Tc = 10.0 min O.m 0.O ° 0.96 0.055 0.05 0.045 E 0.04 fi 0 035 0.03 0.025 0.02 0.015 0.01 0.005 Subcatchment 1S: Sub -Basin 3 (Res Site) 0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Ti. (i .) ■ au,.n Interl irl 1 • • II • o- 1 1 1 1 I MENOMONEE NONE ■NONE ■■■ NONE ■■00 ■■1■■1 .■.■..■■■.■■.■■■E .■■■■■.........■■ 0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Ti. (i .) ■ au,.n Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 5 Summary for Subcatchment 8S: Sub -Basin 1 Runoff = 0.68 cfs @ 0.17 hrs, Volume= 1.337 af, Depth> 5.74" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 121,725 0.20 Woodland & Forests, Hilly 0 0.30 Side Slopes, Earth 121,725 0.20 Weighted Average 121.725 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 500 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 3.0 500 Total, Increased to minimum Tc = 10.0 min Subcatchment 8S: Sub -Basin 1 Hydograph lima (hare) ❑ aunon Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 10S: Sub -Basin 2 Runoff = 0.17 cfs @ 0.17 hrs, Volume= 0.332 af, Depth> 5.74" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 30,210 0.20 Woodland & Forests, Hilly 0 0.30 Side Slopes, Earth 30,210 0.20 Weighted Average 30,210 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 250 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 1.5 250 Total, Increased to minimum Tc = 10.0 min Subcatchment 10S: Sub -Basin 2 Hydrograph lima (hare) ❑ RunoR Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 7 Summary for Reach 1111: On -Site Forest Inflow Area = 2.794 ac, 0.00% Impervious, Inflow Depth > 5.74" Inflow = 0.68 cfs 0.17 hrs, Volume= 1.337 of Outflow = 0.68 cfs 3.20 hrs, Volume= 1.321 af, Atten= 0%, Lag= 181.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.20 fps, Min. Travel Time= 8.5 min Avg. Velocity = 0.20 fps, Avg. Travel Time= 8.5 min Peak Storage= 344 cf @ 3.05 hrs Average Depth at Peak Storage= 0.07' Bank -Full Depth= 0.10' Flow Area= 5.0 sf, Capacity= 1.26 cfs 50.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 100.0' Slope= 0.1000'f Inlet Invert= 989.00'. Outlet Invert= 979.00' Reach 11 R: Onsite Forest XydrogrMh lima (hare) ■Inflmv ■ a wi Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 8 Summary for Reach 12R: On -Site Forest Inflow Area = 0.694 ac, 0.00% Impervious, Inflow Depth > 5.74" Inflow = 0.17 cfs 0.17 hrs, Volume= 0.332 of Outflow = 0.17 cfs 3.83 hrs, Volume= 0.327 af, Atten= 0%, Lag= 219.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.16 fps, Min. Travel Time= 10.3 min Avg. Velocity = 0.16 fps, Avg. Travel Time= 10.3 min Peak Storage= 103 cf @ 3.65 hrs Average Depth at Peak Storage= 0.05' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.50 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 100.0' Slope= 0.1000'f Inlet Invert= 1,063.00', Outlet Invert= 1,053.00' Reach 12R: Onsite Forest ■ mne„ ■a= it ■■■■■■■■■■■■ 1 .11 � ■■■■■■■■■■■■■■■ 1 111 M.. (hw.) Pre -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 9 Summary for Reach 13R: On -Site Forest Inflow Area = 0.262 ac, 0.00% Impervious, Inflow Depth > 5.74" Inflow = 0.06 cfs 0.17 hrs, Volume= 0.125 of Outflow = 0.06 cfs 5.62 hrs, Volume= 0.123 af, Atten= 0%, Lag= 327.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.11 fps, Min. Travel Time= 15.1 min Avg. Velocity = 0.11 fps, Avg. Travel Time= 15.3 min Peak Storage= 58 cf @ 5.37 hrs Average Depth at Peak Storage= 0.03' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.50 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 100.0' Slope= 0.1000'f Inlet Invert= 1,104.00', Outlet Invert= 1,094.00' Reach 13R: Onsite Forest ■ mne„ ■ omm« Appendix D HydroCAD Output Report for 2 -Year Storm Event for Post -Development Conditions 132621 Page D-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir 7R COS 12, Pipe 6R 8S 568 -foot Ditch Sub -Basin 1 -Sheet Flow 3R ^� 12R 2R 1 R Sheet Flow 523 -foot Ditch 94 -foot Ditch \ 1S los Sub -Basin 3 (Res Site) Sub -Basin 2 Subcat Reach on Link Routing Diagram for Post-Develupmerd Prepared by (enter your cornpany name here), Printed 2/19/2020 Hydro M100020 sM 02047 02017 Hydro AD Sd e S funs LLC Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 2 Area Listing (all nodes) Area C Description (acres) (subcatchment-numbers) 0.588 0.85 Gravel Pavement (1S, 8S, 10S) 0.082 0.90 Pavement&Roars (1 S) 0.777 0.30 Side Slopes, Earth (1S, 8S, 10S) 2.344 0.20 Woodland & Forests, Hilly (8S, 10S) 3.750 0.33 TOTAL AREA Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 3 Pipe Listing (all nodes) Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Inside -Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 7R 984.00 983.32 88.0 0.0100 0.010 12.0 0.0 0.0 Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 4 Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by Rational method, Rise/Fall=1.0/1.0 xTc Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Sub -Basin 3 (Res Site) Runoff Area=11.435 sf 0.00% Impervious Runoff Depth>20.38" Flow Length=150' Slope=0.0200'/' Tc=10.0 min C=0.71 Runoff=0.23 cfs 0.446 of Subcatchment BS: Sub -Basin 1 Runoff Area=121.725 sf 0.00% Impervious Runoff Depth>7.75" Flow Length=500' Slope=0.3000'/' Tc=10.0 min C=0.27 Runoff=0.91 cfs 1.805 of Subcatchment 105: Sub -Basin 2 Runoff Area=30.210 sf 0.00% Impervious Runoff Depth>12.34" Flow Length=250' Slope=0.3000'/' Tc=10.0 min C=0.43 Runoff=0.36 cfs 0.713 of Reach 2R: 94 -foot Ditch Avg. Flow Depth=0.24' Max Vel=3.15 fps Inflovr--0.23 cfs 0.446 of n=0.040 L=94.0' 5=0.1691 '/' Capacity=9.69 cfs Outflow=0.23 cfs 0.446 of Reach 5R: Sheet Flow Avg. Flow Depth=0.05' Max Vel=0.24 fps Inflovr--0.23 cfs 0.446 of n=0.400 L=400.0' 5=0.2600'/' Capacity=0.81 cfs Outflow=0.23 cfs 0.429 of Reach 6R: 568 -foot Ditch Avg. Flow Depth=0.50' Max Vel=4.56 fps Inflovr--1.14 cfs 2.233 of n=0.040 L=568.0' 5=0.1514'/' Capacity=135.31 cfs Outflow=1.14cfs 2.227 of Reach 7R: COS 12" Pipe Avg. Flow Depth=0.34' Max Vel=4.88 fps Inflovr--1.14 cfs 2.227 of 12.0" Round Pipe n=0.010 L=68.0' 5=0.0100'f Capacity=4.63 cfs Outflow=1.14 cfs 2.226 of Reach 12R: 523 -foot Ditch Avg. Flow Depth=0.32' Max Vel=2.97 fps Inflovr--0.36 cfs 0.713 of n=0.040 L=523.0' 5=0.1052'/' Capacity=7.64 cfs Outflow=0.36 cfs 0.710 of Reach 13R: Sheet Flow Avg. Flow Depth=0.07' Max Vel=0.27 fps Inflovr--0.36 cfs 0.710 of n=0.400 L=100.0' 5=0.2000'/' Capacity=0.71 cfs Outflow=0.36 cfs 0.704 of Total Runoff Area = 3.750 ac Runoff Volume = 2.964 of Average Runoff Depth = 9.48" 100.00% Pervious= 3.750 ac 0.00% Impervious = 0.000 ac Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 5 Summary for Subcatchment 1S: Sub -Basin 3 (Res Site) Runoff = 0.23 cfs @ 0.17 hrs, Volume= 0.446 af, Depth>20.38" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 2,275 0.90 Pavement & Roofs 5,490 0.85 Gravel Pavement 0 0.20 Woodlands & Forests, Hilly 3,250 0.30 Side Slopes, Earth 420 0.90 Pavement & Roofs 11,435 0.71 Weighted Average 11,435 AM 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 150 0.0200 2.87 Shallow Concentrated Flow, 0.9 150 Total, Increased to minimum Tc = 10.0 min 0. G 0. Subcatchment 1S: Sub -Basin 3 (Res Site) Xydrograph UX;, , , / / , , , , , / , , , / , , , / , / 4,_, , 0 1 2 3 4 5 fi ] 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 lima (hare) . aeon Duration=1,440 min, t en=1.20 in/hr M AM UX;, , , / / , , , , , / , , , / , , , / , / 4,_, , 0 1 2 3 4 5 fi ] 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 lima (hare) . aeon Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 8S: Sub -Basin 1 Runoff = 0.91 cfs @ 0.17 hrs, Volume= 1.805 af, Depth> 7.75" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 91,820 0.20 Woodland & Forests, Hilly 19,555 0.30 Side Slopes, Earth 10,350 0.85 Gravel Pavement 121,725 0.27 Weighted Average 121.725 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 500 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 3.0 500 Total, Increased to minimum Tc = 10.0 min Subcatchment 8S: Sub -Basin 1 Hydro¢aph Y- • • [ • t it / � •r- t ttot I t t I 9 1 2 3 4 5 fi ] 8 9 19 11 12 13 14 15 16 17 18 19 29 21 22 23 24 M. (h .) D RunoR Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 10S: Sub -Basin 2 Runoff = 0.36 cfs @ 0.17 hrs, Volume= 0.713 af, Depth>12.34" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=1.20 in/hr 10,270 0.20 Woodland & Forests, Hilly 11,030 0.30 Side Slopes, Earth 8,910 0.85 Gravel Pavement 30,210 0.43 Weighted Average 30,210 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 250 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 1.5 250 Total, Increased to minimum Tc = 10.0 min Subcatchment 10S: Sub -Basin 2 Hydograph lima (hare) ❑ RunoR Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 8 Summary for Reach 2R: 94 -foot Ditch Inflow Area = 0.263 ac, 0.00% Impervious, Inflow Depth > 20.38" Inflow = 0.23 cfs 0.17 hrs, Volume= 0.446 of Outflow = 0.23 cfs 0.34 hrs, Volume= 0.446 af, Atten= 0%, Lag= 10.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 3.15 fps, Min. Travel Time= 0.5 min Avg. Velocity = 3.15 fps, Avg. Travel Time= 0.5 min Peak Storage= 7 cf @ 0.33 hrs Average Depth at Peak Storage= 0.24' Bank -Full Depth= 1.00' Flow Area= 1.2 sf, Capacity= 9.69 cfs 0.00' x 1.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.2'f Top Width= 2.40' Length= 94.0' Slope= 0.1691 'f Inlet Invert= 1,112.70', Outlet Invert= 1,096.80' Reach 2R: 94 -foot Ditch M.. (hw.) FE —h ■a= Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 9 Summary for Reach 5R: Sheet Flow Inflow Area = 0.263 ac, 0.00% Impervious, Inflow Depth > 20.37" Inflow = 0.23 cfs 0.34 hrs, Volume= 0.446 of Outflow = 0.23 cfs 10.01 hrs, Volume= 0.429 af, Atten= 0%, Lag= 580.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.24 fps, Min. Travel Time= 27.4 min Avg. Velocity = 0.24 fps, Avg. Travel Time= 27.8 min Peak Storage= 370 cf @ 9.54 hrs Average Depth at Peak Storage= 0.05' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.81 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 400.0' Slope= 0.2600'f Inlet Invert= 1,092.00', Outlet Invert= 988.00' Reach 5R: Sheet Flow M.. (hw.) ■ mne„ ■a= Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 10 Summary for Reach 6R: 568 -foot Ditch [62] Hint: Exceeded Reach 5R OUTLET depth by 85.45' @ 8.23 hrs Inflow Area = 3.057 ac, 0.00% Impervious, Inflow Depth > 8.77" Inflow = 1.14 cfs 9.98 hrs, Volume= 2.233 of Outflow = 1.14 cfs 10.02 hrs, Volume= 2.227 af, Atten= 0%, Lag= 2.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 4.56 fps, Min. Travel Time= 2.1 min Avg. Velocity = 4.54 fps, Avg. Travel Time= 2.1 min Peak Storage= 142 cf @ 9.99 hrs Average Depth at Peak Storage= 0.50' Bank -Full Depth= 3.00' Flow Area= 9.0 sf, Capacity= 135.31 cfs 0.00' x 3.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.0'f Top Width= 6.00' Length= 568.0' Slope= 0.1514'f Inlet Invert= 1,073.00', Outlet Invert= 987.00' Reach 6R: 568 -foot Ditch Hydrogaph 944444/47/ 19 11 12 13 14 15 16 17 18 19 28 21 22 23 24 lima (haus) ■ hMmv ■ OUMmv I 944444/47/ 19 11 12 13 14 15 16 17 18 19 28 21 22 23 24 lima (haus) ■ hMmv ■ OUMmv Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 11 Summary for Reach 7R: COS 12" Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 3.057 ac, 0.00% Impervious, Inflow Depth > 8.74" Inflow = 1.14 cfs @ 10.02 hrs, Volume= 2.227 of Outflow = 1.14 cfs @ 10.04 hrs, Volume= 2.226 af, Atten= 0%, Lag= 1.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 4.88 fps, Min. Travel Time= 0.2 min Avg. Velocity = 4.85 fps, Avg. Travel Time= 0.2 min Peak Storage= 16 cf @ 10.02 hrs Average Depth at Peak Storage= 0.34' Bank -Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 4.63 cfs 12.0" Round Pipe n= 0.010 PVC, smooth interior Length= 68.0' Slope= 0.0100'f Inlet Invert= 984.00', Outlet Invert= 983.32' Reach 7R: COS 12" Pipe Hydrograph 9 8 1 2 3 4 5 fi ] 8 9 18 11 12 13 14 15 16 17 18 19 28 21 22 23 24 M. Ihovel ❑ N9ow ❑ outlow 1 1 1 11 r 9 8 1 2 3 4 5 fi ] 8 9 18 11 12 13 14 15 16 17 18 19 28 21 22 23 24 M. Ihovel ❑ N9ow ❑ outlow Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 12 Summary for Reach 12R: 523 -foot Ditch Inflow Area = 0.694 ac, 0.00% Impervious, Inflow Depth > 12.34" Inflow = 0.36 cfs 0.17 hrs, Volume= 0.713 of Outflow = 0.36 cfs 1.46 hrs, Volume= 0.710 af, Atten= 0%, Lag= 77.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 2.97 fps, Min. Travel Time= 2.9 min Avg. Velocity = 2.96 fps, Avg. Travel Time= 2.9 min Peak Storage= 64 cf @ 1.41 hrs Average Depth at Peak Storage= 0.32' Bank -Full Depth= 1.00' Flow Area= 1.2 sf, Capacity= 7.64 cfs 0.00' x 1.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.2'f Top Width= 2.40' Length= 523.0' Slope= 0.1052'f Inlet Invert= 1,118.00', Outlet Invert= 1,063.00' Reach 12R: 523 -foot Ditch M.. (hw.) ■ I-__ ■a= Post -Development Rainfall Duration=1,440 min, Inten=1.20 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 13 Summary for Reach 13R: Sheet Flow Inflow Area = 0.694 ac, 0.00% Impervious, Inflow Depth > 12.29" Inflow = 0.36 cfs 1.46 hrs, Volume= 0.710 of Outflow = 0.36 cfs 2.45 hrs, Volume= 0.704 af, Atten= 0%, Lag= 59.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.27 fps, Min. Travel Time= 6.1 min Avg. Velocity = 0.27 fps, Avg. Travel Time= 6.2 min Peak Storage= 133 cf @ 2.35 hrs Average Depth at Peak Storage= 0.07' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.71 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 100.0' Slope= 0.2000'f Inlet Invert= 1,062.00', Outlet Invert= 1,042.00' 9. 9.@ 9 8 9 19 11 12 13 14 15 1fi 17 18 19 2fi 21 22 23 24 lima (hare) Reach 13R: Sheet Flow Hydrogre h �•������ •W"liji��lji� ■����������� i.bi�i�if■iiii ■nnnnnnnnnnnnnnnnnnn�rTr� . ■nnnnnnnnnnnnnnnnn��srrr�� /1 nnnnnnnnnnnnnn■I�rrrrnnnl■n ■I___ ■aWlwi Appendix E HydroCAD Output Report for 25 -Year Storm Event for Post -Development Condition 132621 Page E-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir 7R COS 12, Pipe 6R 8S 568 -foot Ditch Sub -Basin 1 -Sheet Flow 3R ^� 12R 2R 1 R Sheet Flow 523 -foot Ditch 94 -foot Ditch \ 1S los Sub -Basin 3 (Res Site) Sub -Basin 2 Subcat Reach on Link Routing Diagram for Post-Develupmerd Prepared by (enter your cornpany name here), Printed 2/19/2020 Hydro M100020 sM 02047 02017 Hydro AD Sd e S funs LLC Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 2 Area Listing (all nodes) Area C Description (acres) (subcatchment-numbers) 0.588 0.85 Gravel Pavement (1S, 8S, 10S) 0.082 0.90 Pavement&Roars (1 S) 0.777 0.30 Side Slopes, Earth (1S, 8S, 10S) 2.344 0.20 Woodland & Forests, Hilly (8S, 10S) 3.750 0.33 TOTAL AREA Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 3 Pipe Listing (all nodes) Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Inside -Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 7R 984.00 983.32 88.0 0.0100 0.010 12.0 0.0 0.0 Post-Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 s/n 02047 © 2017 HydroCAD Software Solutions LLC Paae 4 Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by Rational method, Rise/Fall=1.0/1.0 xTc Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Sub-Basin 3 (Res Site) Runoff Area=11.435 sf 0.00% Impervious Runoff Depth>35.67" Flow Length=150' Slope=0.0200'/' Tc=10.0 min C=0.71 Runoff=0.39 cfs 0.780 of Subcatchment BS: Sub-Basin 1 Runoff Area=121.725 sf 0.00% Impervious Runoff Depth>13.56" Flow Length=500' Slope=0.3000'/' Tc=10.0 min C=0.27 Runoff=1.60 cfs 3.159 of Subcatchment 105: Sub-Basin 2 Runoff Area=30.210 sf 0.00% Impervious Runoff Depth>21.60" Flow Length=250' Slope=0.3000'/' Tc=10.0 min C=0.43 Runoff=0.63 cfs 1.248 of Reach 2R: 94-foot Ditch Avg. Flow Depth=0.30' Max Vel=3.63 fps Inflovr--0.39 cfs 0.780 of n=0.040 L=94.0' 5=0.1691 '/' Capacity=9.69 cfs Outflow=0.39 cfs 0.780 of Reach 5R: Sheet Flow Avg. Flow Depth=0.06' Max Vel=0.30 fps Inflovr--0.39 cfs 0.780 of n=0.400 L=400.0' 5=0.2600'/' Capacity=0.81 cfs Outflow=0.39 cfs 0.756 of Reach 6R: 568-foot Ditch Avg. Flow Depth=0.62' Max Vel=5.24 fps Inflovr--1.99 cfs 3.914 of n=0.040 L=568.0' 5=0.1514'/' Capacity=135.31 cfs Outflow=1.99 cfs 3.905 of Reach 7R: COS 12" Pipe Avg. Flow Depth=0.46' Max Vel=5.68 fps Inflovr--1.99 cfs 3.905 of 12.0" Round Pipe n=0.010 L=68.0' 5=0.0100'f Capacity=4.63 cfs Outflow=1.99 cfs 3.903 of Reach 12R: 523-foot Ditch Avg. Flow Depth=0.39' Max Vel=3.41 fps Inflovr--0.63 cfs 1.248 of n=0.040 L=523.0' 5=0.1052'/' Capacity=7.64 cfs Outflow=0.63 cfs 1.244 of Reach 13R: Sheet Flow Avg. Flow Depth=0.09' Max Vel=0.34 fps Inflovr--0.63 cfs 1.244 of n=0.400 L=100.0' 5=0.2000'/' Capacity=0.71 cfs Outflow=0.63 cfs 1.235 of Total Runoff Area = 3.750 ac Runoff Volume = 5.187 of Average Runoff Depth =16.60" 100.00% Pervious = 3.750 ac 0.00% Impervious = 0.000 ac Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 5 Summary for Subcatchment 1S: Sub -Basin 3 (Res Site) Runoff = 0.39 cfs @ 0.17 hrs, Volume= 0.780 af, Depth>35.67" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=2.10 in/hr 2,275 0.90 Pavement & Roofs 5,490 0.85 Gravel Pavement 0 0.20 Woodlands & Forests, Hilly 3,250 0.30 Side Slopes, Earth 420 0.90 Pavement & Roofs 11,435 0.71 Weighted Average 11,435 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 150 0.0200 2.87 Shallow Concentrated Flow, 0.9 150 Total, Increased to minimum Tc = 10.0 min Subcatchment 1S: Sub -Basin 3 (Res Site) Hydrograph or i i i i i i i i i i i i i i i i i i i i i i i 1 9 1 2 3 4 5 fi ] 8 9 19 11 12 13 14 15 16 17 18 19 28 21 22 23 24 lima (hare) ■ au,on Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 8S: Sub -Basin 1 Runoff = 1.60 cfs @ 0.17 hrs, Volume= 3.159 af, Depth>13.56" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=2.10 in/hr 91,820 0.20 Woodland & Forests, Hilly 19,555 0.30 Side Slopes, Earth 10,350 0.85 Gravel Pavement 121,725 0.27 Weighted Average 121.725 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 500 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 3.0 500 Total, Increased to minimum Tc = 10.0 min Subcatchment 8S: Sub -Basin 1 Hydrograph fl e I. t. ., I , , / ; / , , , / / / , / /4 / / / / / / / 411 9 1 2 3 4 5 6 7 8 9 19 11 12 13 14 15 16 17 18 19 29 21 22 23 24 M. (home) o agar Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here) Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 10S: Sub -Basin 2 Runoff = 0.63 cfs @ 0.17 hrs, Volume= 1.248 af, Depth>21.60" Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Rainfall Duration=1,440 min, Inten=2.10 in/hr 10,270 0.20 Woodland & Forests, Hilly 11,030 0.30 Side Slopes, Earth 8,910 0.85 Gravel Pavement 30,210 0.43 Weighted Average 30,210 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 250 0.3000 2.74 Shallow Concentrated Flow, Forest Woodland Kv=5.Ofos 1.5 250 Total, Increased to minimum Tc = 10.0 min Subcatchment 10S: Sub -Basin 2 Hydograph lima (hare) O R�naii Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 8 Summary for Reach 2111: 94 -foot Ditch Inflow Area = 0.263 ac, 0.00% Impervious, Inflow Depth > 35.67" Inflow = 0.39 cfs 0.17 hrs, Volume= 0.780 of Outflow = 0.39 cfs 0.28 hrs, Volume= 0.780 af, Atten= 0%, Lag= 6.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 3.63 fps, Min. Travel Time= 0.4 min Avg. Velocity = 3.62 fps, Avg. Travel Time= 0.4 min Peak Storage= 10 cf @ 0.27 hrs Average Depth at Peak Storage= 0.30' Bank -Full Depth= 1.00' Flow Area= 1.2 sf, Capacity= 9.69 cfs 0.00' x 1.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.2'f Top Width= 2.40' Length= 94.0' Slope= 0.1691 'f Inlet Invert= 1,112.70', Outlet Invert= 1,096.80' Reach 2111: 94 -foot Ditch ❑ Inn— D= =m In ft 17MI111111111 I mmmmmmmmimmmmm- III Max • 3. mmmmmmmmimmmmm 1 1 1 1 ommmmmmmmm ommmmmmmmmmmmmm mmmmmmmmimmmmmmm Ili 1 mmmmmmmmmmmmmmm mmmmmmmmmmmmmmm mmmmmmmmmmmmmmm Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 9 Summary for Reach 5R: Sheet Flow Inflow Area = 0.263 ac, 0.00% Impervious, Inflow Depth > 35.65" Inflow = 0.39 cfs 0.28 hrs, Volume= 0.780 of Outflow = 0.39 cfs 7.85 hrs, Volume= 0.756 af, Atten= 0%, Lag= 454.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.30 fps, Min. Travel Time= 21.9 min Avg. Velocity = 0.30 fps, Avg. Travel Time= 22.2 min Peak Storage= 519 cf @ 7.48 hrs Average Depth at Peak Storage= 0.06' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.81 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 400.0' Slope= 0.2600'f Inlet Invert= 1,092.00', Outlet Invert= 988.00' Reach 5R: Sheet Flow XydrogrMh lima (hare) mn ❑ ow L ❑o Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 10 Summary for Reach 6R: 568 -foot Ditch [62] Hint: Exceeded Reach 5R OUTLET depth by 85.55' @ 6.47 hrs Inflow Area = 3.057 ac, 0.00% Impervious, Inflow Depth > 15.37" Inflow = 1.99 cfs 7.85 hrs, Volume= 3.914 of Outflow = 1.99 cfs 7.89 hrs, Volume= 3.905 af, Atten= 0%, Lag= 2.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 5.24 fps, Min. Travel Time= 1.8 min Avg. Velocity = 5.22 fps, Avg. Travel Time= 1.8 min Peak Storage= 216 cf @ 7.86 hrs Average Depth at Peak Storage= 0.62' Bank -Full Depth= 3.00' Flow Area= 9.0 sf, Capacity= 135.31 cfs 0.00' x 3.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.0'f Top Width= 6.00' Length= 568.0' Slope= 0.1514'f Inlet Invert= 1,073.00', Outlet Invert= 987.00' Reach 6R: 568 -foot Ditch Hydrogaph �,,.,,,10�111, IIS 9 1 2 3 4 5 6 7 8 9 19 11 12 13 14 15 16 17 18 19 28 21 22 23 24 lima (haus) ❑ Inn— ❑ =-- Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 11 Summary for Reach 7R: COS 12" Pipe [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 3.057 ac, 0.00% Impervious, Inflow Depth > 15.33" Inflow = 1.99 cfs 7.89 hrs, Volume= 3.905 of Outflow = 1.99 cfs 7.90 hrs, Volume= 3.903 af, Atten= 0%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 5.68 fps, Min. Travel Time= 0.2 min Avg. Velocity = 5.65 fps, Avg. Travel Time= 0.2 min Peak Storage= 24 cf @ 7.89 hrs Average Depth at Peak Storage= 0.46' Bank -Full Depth= 1.00' Flow Area= 0.8 sf, Capacity= 4.63 cfs 12.0" Round Pipe n= 0.010 PVC, smooth interior Length= 68.0' Slope= 0.0100'f Inlet Invert= 984.00', Outlet Invert= 983.32' n Reach 7R: COS 12" Pipe Hydrugraph 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 M. (h .) ■ Infi— ■2"O ZO 11111111111111111111 r ! i � r 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 M. (h .) ■ Infi— ■2"O Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 12 Summary for Reach 12R: 523 -foot Ditch Inflow Area = 0.694 ac, 0.00% Impervious, Inflow Depth > 21.60" Inflow = 0.63 cfs 0.17 hrs, Volume= 1.248 of Outflow = 0.63 cfs 1.27 hrs, Volume= 1.244 af, Atten= 0%, Lag= 66.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 3.41 fps, Min. Travel Time= 2.6 min Avg. Velocity = 3.41 fps, Avg. Travel Time= 2.6 min Peak Storage= 97 cf @ 1.22 hrs Average Depth at Peak Storage= 0.39' Bank -Full Depth= 1.00' Flow Area= 1.2 sf, Capacity= 7.64 cfs 0.00' x 1.00' deep channel, n= 0.040 Earth, cobble bottom, clean sides Side Slope Z -value= 1.2'f Top Width= 2.40' Length= 523.0' Slope= 0.1052'f Inlet Invert= 1,118.00', Outlet Invert= 1,063.00' 0.t 0. Reach 12R: 523 -foot Ditch Hydrogaph 0 1 2 3 4 5 fi ] 8 9 10 11 12 13 14 15 1fi 1] 18 19 20 21 22 23 24 lima (h.) ■loam ■ aW mi ii ■iiiiiiiiiiii��) ■■■■■■■■■■■■■■■■■■■oma ■■■■■■■■■■■■■■■■■■■■■■■■ 0 1 2 3 4 5 fi ] 8 9 10 11 12 13 14 15 1fi 1] 18 19 20 21 22 23 24 lima (h.) ■loam ■ aW mi Post -Development Rainfall Duration=1,440 min, Inten=2.10 in1hr Prepared by {enter your company name here} Printed 2/19/2020 HydroCAD® 10.00-20 sln 02047 © 2017 HydroCAD Software Solutions LLC Paae 13 Summary for Reach 13R: Sheet Flow Inflow Area = 0.694 ac, 0.00% Impervious, Inflow Depth > 21.52" Inflow = 0.63 cfs 1.27 hrs, Volume= 1.244 of Outflow = 0.63 cfs 2.02 hrs, Volume= 1.235 af, Atten= 0%, Lag= 45.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Max. Velocity= 0.34 fps, Min. Travel Time= 4.9 min Avg. Velocity = 0.34 fps, Avg. Travel Time= 4.9 min Peak Storage= 186 cf @ 1.94 hrs Average Depth at Peak Storage= 0.09' Bank -Full Depth= 0.10' Flow Area= 2.0 sf, Capacity= 0.71 cfs 20.00' x 0.10' deep channel, n= 0.400 Sheet flow: Woods+light brush Length= 100.0' Slope= 0.2000'f Inlet Invert= 1,062.00', Outlet Invert= 1,042.00' Reach 13R: Sheet Flow Hytlrogre h lima (hare) ■Inflmv ■ aW wi Appendix F Level Spreader and Riprap Sizing Calculations 19-2621 Page F-1 Stormwater Study April 2020 SUB South Hills 4th Level Reservoir SPRINGFIELD UTILITY BOARD South Hills 4th Level Reservoir SUB Project No. 18810 Murraysmith Project No. 19-2621 Level Spreader Calculations =:3/24/2020 By:. Calculate the length of a broad -crested weir to pass a given flowrate, assuming head Parameter Value Units Notes cid, g0o GPM Maximum pumping velocity to reservoir Qd", 1.]8 rfs C, 1.60 unitless H LO in H o.l] ft L- Q / (Co * H13) Parameter Value Units length L 16.37 ft SPRINGFIELD UTILITY BOARD South Hills 4th Level Reservoir SUB Project No. 18810 Murraysmith Project No. 19-2621 Riprap Sizing Calculations Date: 3/27/2020 Forebay - Bed Material Sizing Calculations I Tractive Force Design Ca Ics using Chapter 15 of the ODOT Hvd ra ul i cs Manual AVERAGE SCOUR MATERIAL SIZE D,,=0.001 C V,' d„s 0.5 K11.5 Ds, = 0.032 feet D.= 0.4 inches Where By: Equation 15-6, ODOT Hydraulics Manual, Chapter 15 Bank Protection D, = scour material median equivalent spherical diameter, ft C = correction factor V, = average velocity of the main channel, fps d,,,e= average depth of the main channel, ft K, = incipient motion tractive force ratio of sloping surface to the level surface INCIPIENT MOTION TRACTIVE FORCE RATIO Kt = [ 1- sin 2@ / sin2q� los K, = 0.219 Where: () = bank angle with the horizontal, degrees �P = scour material angle of repose, degrees Approximate Bank Slope = 0 = 1.2 H : 1V Based on Channel Geometry Below D = 40 degrees Angle of repose = (See FHWA chart below) (1)= 41 degreesfor D,,= 1.5 inches = 0.1 feet Page 1 of 3 CORRECTION FACTOR C = Specific Gravity correction factor (C,)x Stability correction factor (C,,) C = 1.00 Where C,e = 2.12 (Sa - 1)" C,e = 1.00 Where: S, = 2.65 And: C,f = (0.83 SF)" C,f = 1.00 Where: SF = 1.20 AVERAGE VELOCITY OF MAIN CHANNEL Q= 1,000 GPM = 2.23 CFS V. = 1.39 feet per second AVERAGE DEPTH OF MAIN CHANNEL da, = Achaarei / WcMnnei dam = 0.67 feet Equation 15-8, ODOT Hydraulics Manual, Chapter 15 Bank Protection Per Table 15-1, ODOT Hydraulics Manual, Chapter 15 Bank Protection Equation 15-9, ODOT Hydraulics Manual, Chapter 15 Bank Protection Per Table 15-9, ODOT Hydraulics Manual, Chapter 15 Bank Protection 800 GPM for Reservoir Overflow + Runoff Where: Model channel as parabolic, use smallest channel section for highest velocity Wchannd(b)= 2.4 feet Dchannd(a)= 1 feet Achannei = 1.60 square feet Page 2 of 3 43 37 Angles of Repose of Riprap Stones (FHWA) MEAN STONE WC. USO, ft If■iai� ■V■■■V1��1��ir� ■ 1m■ :nlMr��lir� �Ei�l�rrrrrrr■ �������!_ Jr•rrrlr�r• Andesite 2,5-2.8 Basalt/'hapn k ■Lill ■�WAM■■■■1millions misimmim■ 2.6-3.0 ]Diorite 2N-30 8 10 20 40 60 100 200 400 600 MEAN 5TQNE SIZE. oyo, trout Table 15-1 Specific Gravities of Typical Oregon Riprap Stone (Based no a 62.4 pound per cubic foot water density-) Rock Tvne Specific GTayity Ranee of Tvnical Rock Andesite 2,5-2.8 Basalt/'hapn k 2.8-3.0 ]Diabase 2.6-3.0 ]Diorite 2N-30 Gneiss 2-6 — 2-9 Granite 2.6-2.7 Limestone 2.3-2.7 Marble 2.4-2.7 Quartzite 2,6-28 Rhyolite 24-26 Table 1S9 Guidelines for the Selection of Stability Factors Flow Condition Stability Factor Rime Uniform tlow; Straight or mildly curving reach (curve mdius/channel width isre than 3 m 0); ipact f,.—wave action and floating debris 1.0— r.2 .nalox.ade or no mi,erno-ty in deAgrt paganneur.. Gradually varying new; Moderate bend curvatura (30 is mono Wmm radius channel width is mare than 10); impact from waves, ice 1.3 - 1.6 or floating debris moderate. Approaching rapidly varying flow; Sharp bend curvature (curve radius/channel width is less than 10); Significant impact potential from floating debris and/or ice; Significant wind and/or boat 17 2.n generated waves (l - 2 feet); High flow turbulence; Turbulently mixing flow at bridge abutments; Significant uncertainty in design arameters. Page 3 of 3