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APPENDIX B <br />Runoff Treatment Calculations <br />� Peak volume for G month 24-hour storm event <br />Proposcd conditions (driveable sw•face = 0.97 acres): 2584 cf <br />, (sec Project Precipitation Values in Appendix A). <br />Wctpon�i Design per Ciry oC Everett Stormwater Management Manual (ESMM) Section 3-3.5 <br />Desien Criteria: <br />1. Combined pernianent pool volume equals volume of runoff from the 6 month 24 hour storm = <br />2584 cf <br />2. Required volume for Vegetated treatment ce1L• minimum 15% of wet pond volume = 0.15 * 2584 <br />cf = 388 cf . Provided: 388 cf <br />3. Required vo;ume for Open water celL• maximum 85% of wetpond volume = 0.85 * 2584 cf = 2196 <br />cf required. Provided: 2200 cf (= 75% oF provided wetpond volume) <br />4. 72" catch basin provided. <br />S. Access p�th provided along the side of the wetpond. <br />6. Vegetated cell located after the open water cell. <br />7. Earthern berm with side slopes of 3:1 extending to the permanent pool water elevation provided. <br />8. 3:1 length to width ratio provided. <br />9. The soils are Aldenvood Type C per SCS Soil Survey from Snohomish County. A liner is not <br />required. <br />10. See landscaping plans for landscaping, <br />I l. Six inches of top soil per City requirements provided. <br />12. See landscaping plans for wedand vegetation. <br />13. Pond access provided per ESMM Section 3.1. <br />Q�.UROGIICivi�Cnginccr\RcpurtslStormwalcr Rcport Suhmiticd May 01�Appcndix B_malificd.Joc <br />� <br />SI292003 <br />Page 1 of <br />� ��ls <br />