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<br />Cripple Creek & Victor Gold Mining Company Exhibit U <br />Cresson Project Amendment 13 <br /> 13 <br />9 SURFACE WATER CONTROL AND CONTAINMENT INFORMATION <br />Stormwater for the Cresson Project is managed under the Stormwater Management Plan <br />(SWMP), which is reviewed and updated annually. The SWMP details mining activities, effluent <br />limitation guidelines, stormwater management controls, identification of potential pollutant <br />sources, best management practices, schedules and procedures, and comprehensive inspection <br />requirements. As designated by this plan, all stormwater management features are inspected on <br />a quarterly basis and following significant precipitation events. The SWMP is provided in Appendix <br />3. <br />In 2018, an evaluation of the SWMP and stormwater control features was completed by Knight <br />Piesold Consulting, as approved under Technical Revision (TR) 101 (TR-101). Outcomes of this <br />evaluation included: <br /> Updated design event precipitation values (NOAA 2013 Atlas 14, Volume 8). <br /> Updated curve number assignments per the NRCS (SCS) curve number runoff <br />method. <br /> Recommended improvement of some stormwater management features to comply <br />with updated curve numbers and design events. <br />Improvements for several features will be completed in 2019 and the SWMP will be <br />updated to reflect these changes. <br />EMP ponds have been configured to be less than 10 feet in height when measured from <br />the existing grade at the downstream toe to the spillway, and excavated an additional five <br />feet below grade to provide the optimum depth of 15 feet. Embankments of less than 10 <br />feet in height are not regulated by the Division of Water Resources, Office of the State <br />Engineer under the Dam Safety Regulations. <br />9.1 Surface Water Quality Data <br />Regionally, surface water flows from the Cresson Project area are tributary to the Upper Arkansas <br />River basin. Surface water flows into Grassy Valley, a tributary to Beaver Creek on the north side. <br />Surface water flows into Theresa Gulch and Bateman Creek, both tributaries to Wilson Creek, <br />which flows into Fourmile Creek on the south. The drainages flowing west are Poverty Gulch, <br />Squaw Gulch, and Arequa Gulch, from north to south. These streams are all tributaries to Cripple <br />Creek, which also flows into Fourmile Creek. A discussion of surface water quality is provided in <br />Exhibit G and supporting data is provided in Appendix 6. These data include at least five <br />successive calendar quarters. Figure G-2 in Exhibit G shows the surface water rights for a two- <br />mile radius around the Affected Lands boundary.