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<br /> <br /> <br /> <br />COMPREHENSIVE STORMWATER MANAGEMENT PLAN <br />CITY OF HUGO <br />WSB PROJECT NO. 1904-610 PAGE 2 <br /> CITY-WIDE VOLUME REDUCTION REQUIREMENTS: CREDIT DEMAND <br /> <br />A. Credit Valuation <br /> <br />Using the City of Hugo’s 2040 planned land use and comparing it to 2005 land uses, the water <br />quality treatment volume required for a full-build out of Hugo is estimated using the RCWD’s Rule <br />C. Rule C states that 1.1 inch of volume reduction/water quality treatment is required for new or <br />reconstructed impervious areas for all development and redevelopment projects, with the <br />exception of Public Linear Projects. For Public Linear Projects, it is anticipated that Rule C will be <br />updated at the end of 2020 to state that 1.0 inch of volume reduction/water quality treatment is <br />required for new impervious areas greater than 10,000 square feet. To estimate the increase in <br />impervious area, a GIS analysis of existing versus future impervious area for each subwatershed <br />was conducted (Appendix A – Figures 1, 2, and 3). <br /> <br />Based on the Credit Valuation Guide in Appendix B, the City will distribute credits based on BMP <br />size requirements for the new or reconstructed impervious surface. The required BMP volume <br />must be calculated using RCWD’s Rule C. <br /> <br /> <br />0.0540 <br /> <br />Development and redevelopment projects that are not city-funded public linear projects must pay <br />the City for use of volume credits. Based on average construction cost of a typical wet pond BMP <br />and land value cost in Hugo, each credit shall cost $18,050 (Appendix B). This value may be <br />reviewed and adjusted as costs fluctuate. <br /> <br />B. Public Linear Projects <br /> <br />Road improvement projects require stormwater management, though the required treatment <br />volume is less than land development projects. For public linear projects, it is anticipated that <br />Rule C will be updated at the end of 2020 to state that 1.0 inch of treatment must be provided for <br />new impervious surfaces greater than 10,000 square feet. The CSMP assumes the 1.0 inch for <br />public linear projects will be adopted by RCWD and applies that standard. <br /> <br />The annual reuse treatment volume required was calculated by assuming that the standards for <br />public and private development capture 19.87 inches and 20.38 inches of rainfall annually, <br />respectively. In other words, capturing 1.0 inch off of impervious for each rainfall event—as is <br />required for public linear projects—is comparable to using 19.87 inches of stormwater annually <br />over the same area. These values were provided by RCWD and dictate the amount of irrigation <br />required for stormwater reuse projects. <br /> <br />Based on the Credit Valuation Guide in Appendix B, one volume credit (one acre-foot of <br />irrigation annually) will sufficiently provide stormwater volume control for 0.615 acres of <br />impervious increase for public linear projects. It is anticipated that approximately 30,000 sf of new <br />impervious will be created annually from public linear projects, however that number will likely <br />fluctuate based on the City’s CIP needs. <br />