5tormwater 5urtace Filtration/Infiltration Facility 51zing 5preadsneet <br />24 Hour Storm, NRCS Type 1A Rainfall Distribution <br />City of Eugene <br />Version 2.1 <br />Project Information <br />Project Name: Oaklei h Meado Cohousin Date: /113 /2013 <br />Project Address: Oakleigh Lane Permit Number: <br />Eugene, OR 97402 Catchment ID: Rain Garden 5 <br />Designer: Michael A Cox j <br />Company: SSW Engineeers_Inc. <br />Instructions: <br />1. Complete this form for each drainage catchment in the project site that is to be sized per the Presumptive Approach. <br />2. Provide a distinctive Catchment ID for each facility coordinated with the site basin map to correlate the appropriate <br />calculations with the facility. <br />3. The maximum drainage catchment to be modeled per the Presumptive Approach is 1 acre (43,560 SF) <br />4.For infiltration facilities in Class A or B soils where no infiltration testing has'been perffomed 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 />Design Requirements:. I <br />Choose "Yes" from the'dropdown boxes below next to the design standards requirements for this facility. <br />Pollution Reduction (PR) Yes <br />Flow Control (FC) Yes <br />Destination (DT) NO -An Inorat(m faci0ty must be chosen as the fackay type to meet destination requirements <br />Site Data-Post Developrrient ' <br />Total Square Footage Impervious Area= 927 sgft Total Square Footage Pervious Area=~sgft <br />Impervious Area Ch 98 Pervious Area CN= 85 <br />Total Square Footage of Drainage Area= 927 sft Time of Concentration Post Development=min <br />Weighted Average Cl 98 <br />Site.Data-Pre Development (Data in this section is.only used if FloW Control is required) • - <br />Pre-Development CN= 85 Time of Concentration Pre-Development= 10 min <br />Soil Data <br />Tested Soil Infiltration Rate= <br />2.5 <br />to/hr (see Note4) Destination Design= in/hr <br />Design Soil Infiltration Rate= <br />2.5 <br />in/hr Soil Infiltration Rate <br />Design Stonns Used For Calculations <br />Requirement <br />Rainfall Depth Design Stonn <br />Pollution Reduction <br />1.4 <br />Inches Mater Quality <br />Flow Control <br />3.6 <br />inches Flood Control <br />Destination <br />3.6 <br />inches Flood Control <br />Facility Type= Filtration Rain Garden Facility Surface Area= 100 <br />sgft <br />Surface Width= 5 ft Facility Surface Perimeter=( 50 <br />ft <br />Surface Length= 20 ft Facility Bottom Area=1 34 <br />sqft <br />Facility Side Slopes=1 31to 1 Facility Bottom Perimeter=( 38 <br />ft <br />Max. Ponding Depth <br />i--J <br />in Stormwater Facility= <br />in Basin Volume= 35.8 <br />cf <br />Depth of Growing Medium (Soil)=L - 18 iri - Ratio of Facility Area to Impervious Area= 0.108 <br />3/11/2013 10:55 AM 1 587 <br />