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Basin F is 8.84 acres. <br /> Water in this basin flows off the crowned roadway and then through vegetation following <br /> the natural topography. <br /> Vegetation in Basin E is shrubs, pinyon and juniper trees, and native grasses. <br /> The access road will be widened and surfaced with gravel. Increases in surface water from <br /> the road improvement is decreased by releasing water at the detention pond at rates slower <br /> than the historical flow in Basin C. <br /> STORMWATER MANAGEMENT <br /> No Drainage Basin Planning Study (DBPS)has been completed for the project site and we are not <br /> aware of any Master Development Drainage Plans (MDDP's) on file. <br /> Fremont County Regulations adopted in January of 2020 require that peak flows exiting the <br /> developed site for the ten (10) year and one hundred (100) year storm events shall not exceed the <br /> respective historic (undeveloped)peak flow of the same event. The USDA TR-55 method must be <br /> used to determine the peak flow for areas over than Twenty (20) acres. The Rational Method must <br /> be used for basins less than 20-acres. <br /> Basins B, C and F are the areas where development is proposed for the project. Peak discharge <br /> flows were determined in these basins for pre-development 10 year and 100-year frequency storm <br /> events. Peak discharges were determined for the proposed development accounting for an increase <br /> in impermeable areas. <br /> Hydrologic calculations were completed using the commercially available Hydrology Studio <br /> program and method required by the county. <br /> Hydrologic Criteria <br /> The USDA TR-55 hydraulic calculation method was used for determination of peak flows in <br /> basins over 20-acres (Basins A and E). The rational method was used in basins less than 20-acres <br /> as required in the Fremont County regulations. Hydrologic calculations were based on the <br /> following assumptions. <br /> • Design storm (minor) 10-year <br /> • Design storm (major) 100-year <br /> • Rainfall intensities Canon City I-D-F Curve <br /> • Hydraulic Soil Type D <br /> • Storm Duration 10 and 24 hours <br /> Calculations and hydrographs are included in Appendix B. <br /> N <br /> N <br /> O <br /> N <br /> 00 <br /> N <br /> c-I <br />