2016-02-03_PERMIT FILE - C1981038 (2)

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52.04 APPLICATION FOR PERMIT FOR SIIRFACE OR UNDERGROUND MINING ACTIVITIES -- MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOIIRCES. 2,04.7 Hydrology Description. (2) Surface Water Information. (a) and (b) (Cont'd.) occur during the winter months when surface runoff is minimal and most of the flow represents groundwater discharge from the watershed, Tributary streams sup- porting agricultural activities typically experience very low flows during late summer cdnen irrigation de- mands are high. Total annual runoff in the Upper Main stem of the Colo- rado River in Colorado is about 5,389,700 ac re feet af- ter adjustment for transbasin diversion (see Table 2.04-8 in the Surface Water Appendix, Volume 4). Total consumptive use within the Upper Main Stem watershed is about 1,189,700 acre-feet or about 22 percent of the available supply, Approximately 76 percent of the con- sumptive use is for irrigation, About 1.5 percent is used for industrial and commercial purposes, and only 4.4 percent for municipal and rural supplies. The re- • mainder is dissipated primarily by evapotranspiration in conjunction with non-beneficial uses, Of the nine sub-basins listed in Table 2.04-8 only the North Fork may be impacted by the existing Orchard Valley Mine. The average annual discharge of the North Fork of the Gunnison River is 313,500 acrefeet, which drains 513 square miles with an average elevation of 8,700 feet. This is a water yield of 602 acre-feet per square mile, The consumptive use from this flow in the North Fork Valley as of 1962 totalled 100,770 acre-feet annually, of which 77,850 acre-feet were used for agriculture, 17,173 acre-feet were used by riparian vegetation, and 6,014 acre-feet were used for recreation, domestic, mu- nicipal, and losses to evaporation (Soil Conservation Service, 1962). Water flows and water quality in the North Fork are strongly influenced by water control through Paonia Reservoir, by water withdrawal from several irrigation canals, and by reflow from irrigated lands back into the river. Withdrawals at Somerset (Fire Mountain Ca- nal), between Bowie and Paonia (Stewart Ditch), and Revised 08/01/84 . Revised 12/26/84 Revised 10/01/87 43