Yaw_ <br />__a <br />OWI IIIW4LU1 JUI IMA: rlrU <br />dl1U11111111tU <br />d11U1 I rdl.IJlly JILIIIIJ. JLJICCIUb1leOL <br />24 Hour Storm; NRCS Type 1A Rainfall Distribution <br />City of Eugene <br />Version 2.1 <br />Project Information I <br />Project Name: Oakleigh Meadows Cohousinct Date: 3111/2013 <br />Project Address: Oakleigh Lane Permit Number: <br />Euuene. OR 97402, Catchment ID: Rain Garden 1 <br />Designer: Michael A Cox <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 orB 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 topsoiUgrowing medium. <br />Design Requirements: <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 'M infiltration facilfly must be chosen as the facility type to meet destination requilemenis <br />Site Data-Post Development <br />Total Square Footage Impervious Area= <br />1923 <br />sqft Total Square Footage Pervious Area= <br />sgft <br />Impervious Area CN= <br />98 <br />Pervious Area CN= 85 <br />~ <br />Total Square Footage of Drainage Area= <br />1923 <br />sft Time of Concentration Post Development=EL~5min <br />Weighted Average CN= <br />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 Soli Infiltration Rate= <br />2.5 <br />in/hr (see Note 4) Destination Design= In/hr <br />Design Soil Infiltration Rate= <br />2.5 <br />in/hr Soil Infiltration Rate <br />Design Storms Used For Calculations <br />Requirement <br />Rainfall Depth <br />Design Stomi <br />Pollution Reduction <br />1.4 <br />inches <br />Water Qual' <br />Flow Control <br />3.6 <br />inches <br />Flood Control ; <br />Destination <br />.3.6 <br />inches <br />Flood Control <br />EacilltyData_.:.. . _ <br />Facility Type= Filtration Rain Garden Facility Surface Area= 182 sqft <br />Surface Width= Aft Facility Surface Perimefer-{ 6618 <br />Surface Length=1 261ft Facility Bottom Area=[ 921sgft <br />_ <br />_ <br />Facility Side Slopes=I 3'to 1 Facility Bottom Perimeter=1 541 ft <br />Max. Ponding Depth <br />in Stormwater Facility= I in. Basin Volume=1 70.7Icf <br />Depth of Growing Medium (Soil)= 18 In Ratio of Facility Area to Impervious Area= 0.095 <br />3/11/2013-10:54'AM 1 579 <br />