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<br />RCWD Alternative Compliance Sequencing Report <br />City of St. Anthony Village PAGE 20 <br />WSB Project No. 1626-53 <br />IV. STORMWATER MANAGEMENT BMPS <br /> <br />Existing and future stormwater management BMPs undertaken by the City are provided in <br />this Section. The water quality benefits provided by these BMPs are also estimated based <br />on equivalent annual volume reduction conversion presented in Section III. Constructed <br />and planned linear projects that will benefit from these BMPs are listed in the Plan under <br />Section V. <br /> <br />A. Inventory of Existing Water Quality BMPs Recognized by RCWD <br />The following stormwater BMPs have been constructed by the City of St. Anthony <br />Village to address the volume reduction requirements set forth by the RCWD. A <br />brief description of existing BMPs that have been used to meet RCWD permit <br />requirements along with the stormwater volume credits achieved is listed below. <br />Refer to Figure 4 for the location of the existing BMPs. <br /> <br />1. St. Anthony Water Reuse Facility (RC Ditch 3 Watershed) <br />The City constructed a stormwater system in 2008 that captures and stores <br />stormwater to be reused for irrigation. The system has a storage capacity of <br />66,840 cubic feet and provides irrigation to 20 acres. The RCWD <br />recognizes that credits for the facility are warranted and the City is <br />continuing monitoring activities on the facility to determine the final credits <br />that will be granted by the RCWD. At this time, monitoring results indicate <br />that the project reduces discharges to surface waters by 683,156 cubic feet <br />annually. <br /> <br />2. Foss Road Biofiltration Swale (RC Ditch 3 Watershed) <br />The City constructed a biofiltration swale off of Foss Road as part of the <br />2009 Street and Utility Improvement Project. RCWD estimated a credit of <br />12,478 cubic feet of water quality treatment for the first 0.8-inches of runoff <br />for this BMP. This credit can be converted to an equivalent annual volume <br />reduction credit of 222,732 cubic feet using an estimated conversion factor <br />of 17.85. This conversion factor is the estimated ratio of annual stormwater <br />volume reduction to volume reduction for the first 0.8-inches of runoff. <br /> <br />It should be noted that the RCWD has limited recognized credits for this <br />BMP based on the impervious surfaces reconstructed for the project. <br />However, the filtration BMP treats runoff from a much larger drainage area <br />than the limits of the project. <br /> <br />3. Filtration BMPs for 2011 Street Improvements (Silver Lake Watershed) <br />The City constructed three filtration BMPs to obtain a RCWD permit to <br />construct its 2011 Street Improvement Project. 1,742 cubic feet of <br />equivalent volume reduction credits are provided by these BMPs. This <br />credit is converted to an annual volume reduction of 31,095 cubic feet using <br />the estimated conversion factor of 17.85.