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EXHIBIT G WATER INFORMATION <br /> 6.4.7(1) and 6.4.7(2) <br /> Surface Water <br /> Two perennial drainages flow through the site. The site is well outside of FEMA identified <br /> floodplains. Maps C-1 shows surface water information for the pre-mine conditions of the area. <br /> Protection of the prevailing hydrologic balance with regard to surface water is achieved by: <br /> • Ensuring that offsite discharge is the same or less following mining: <br /> • Ensuring that offsite discharge velocity is equal or less than pre-mine: <br /> OR <br /> • Ensuring that offsite discharge velocity for new discharge paths is non-erosive (<5 fps). <br /> • Preventing an increase in sediment discharge from the site. <br /> In conjunction with these goals. water quality is ensured during mining by complying with <br /> required CDPHE discharge permits. Finally, protecting the prevailing hydrologic balance means <br /> ensuring that no area water rights are injured through runoff diversion. The water handling plans <br /> for the Siskin Pit were designed to accomplish these goals. <br /> Pre-mining Stn•fuce Hydrologi <br /> Surface flows that do not occur within the active mining area will be diverted around the <br /> disturbed area via > 24"-foot-tall isolation berms and will infiltrate into the native soils of the <br /> undisturbed areas of the site within 72 hours. Precipitation and runoff that enters the pit is <br /> expected. based on current mining efforts at the site. to infiltrate via the pit floor within 72 hours. <br /> In the event that infiltration is not complete 72 hours following a storm event, sediment free <br /> stormwater will be pumped to the approved CDPHE discharge points. Appendix I maps show <br /> the approximate direction of drainage throughout the site prior to mining. during mining, and <br /> post-mining during reclamation as well as stormwater berm locations. <br /> Siskin Pit <br /> Junuarl 2024 G-1 <br /> ONid,I h lSSOCiatr� <br />