Project Name: <br />Project Address: <br />)esigner: <br />:ompany: <br />nstructions: <br />Stormwater Surface Filtrationllnfiltration Facility Sizing Spreadsheet <br />24 Hour Storm, NRCS Type 1A Rainfall Distribution <br />City of Eugene <br />Version 2.1 <br />Oakleigh Meadows Cohousing <br />Aakleioh Lane <br />Eugene, OR 97402 <br />Michael A Cox <br />W En ineeers Inc. <br />Date: 3/11/2013 <br />Permit Number: <br />Catchment ID: Rain Garden 10 <br />Complete this form for each drainage catchment in the project site that is to be sized per the Presumptive Approach. <br />Provide a distinctive Catchment ID for each facility coordinated with the site basin map to correlate the appropriate <br />calculations with the facility. <br />The maximum drainage catchment to be modeled per the Presumptive Approach is 1 acre (43,560 SF) <br />For infiltration facilities in Class A or B soils where no infiltration testing has been perfromed use an infiltration rate of 0.5 in/hr <br />For all facilities use a maximum soil infiltration rate of 2.5 in/hr for topsoil/growing medium. <br />€rements• <br />"Yes" from the dropdown boxes below next to the design standards requirements for this facility. <br />I Pollution Reduction (PR) Yes <br />Flow Control (FC) Yes <br />Destination (DT) No 'M iniiltration facility must be chosen as the facility type to meet destination requirements <br />Site Data-Post Development <br />Total Square Footage Impervious Area= 1567 sqft <br />Impervious Area ( N= 98 <br />Total Square Footage of Drainage Area= 1567 sit <br />Weighted Average Cl 98 <br />Total Square Footage Pervious Area=sgft <br />Pervious Area CN= 85 <br />Time of Concentration Post Development=min <br />IS€te Data-Pre Development (Data in this section is only used If Flow Control is required) I <br />I Pre-Development CN= 85 Time of Concentration Pre-Development= 10 min <br />Soli Data <br />Tested Soil Infiltration Rate= 2.5 in/hr lsee Note 4) Destination Design= in/hr <br />Design Soil Infiltration Rate= 2.5 inlhr Soil Infiltration Rate <br />Design Storms Used For Calculations <br />Requirement _ <br />Rainfall Depth <br />Deslgn Storm <br />Pollution Reduction <br />1.4 inches <br />Water Quality <br />Flow Control <br />3.6 <br />]riches <br />Flood Control <br />Destination <br />3.6 <br />inches <br />Flood Control <br />Facility Data <br />Facility Type= Filtration Rain Garden <br />Facility Surface Area= 150 sgft <br />Surface Width=l 6ft <br />Facility Surface Perimeter= 62 ft <br />Surface Length=1 25 ft <br />~ <br />Facility Bottom Area= 66 sgft <br />to 1 <br />Facility Side Slopes= <br />Facility Bottom Perlmeter= 50 ft <br />Max. Ponding Depth <br />I <br />1 <br />in Stormwater Facility= <br />6 <br />in <br />Basin Volume= 56.2 cf <br />I Depth of Growing Medium (Soil)=L 18 in <br />Ratio of Facility Area to Impervious Area= 0.096 <br />3/11/2013-10:56 AM 11 42 5 <br />