Laserfiche WebLink
Loveland. The amount leased will adequately account for the consumptive uses associated with <br /> the mining operation. <br /> The mining is planned to begin in March 2000 and will occur in three phases lasting <br /> approximately 15 to 17 years. Reclamation will last approximately another 2 to 4 years. After <br /> mining, the majority of the area will be backfilled. The mining operation will create a 28-acre <br /> lined lake after reclamation in the southwestern comer of the permit area. <br /> PROJECTED CONSUMPTIVE USE <br /> Water use at the site will include evaporation from exposed groundwater and water retained from <br /> material removed from the site. <br /> Evaporative Losses <br /> The NOAA Technical Report N WS 33, Evaporation Atlas for the Contiguous 48 United States <br /> (U.S. Department of Commerce) was used to determine gross evaporation. For this location, the <br /> annual evaporation is 38.0 inches (Table 1). Monthly evaporation percentages as suggested by <br /> the Office of the State Engineer were used to calculate monthly evaporation. <br /> Precipitation was estimated using Colorado Climate Center Website data. A copy has been <br /> enclosed for your reference. Annual precipitation at this site was assumed to be equal to that at <br /> the nearest gage station which is the Loveland NCWCD station. The annual mean precipitation is <br /> 14.74 inches (Table 1). Effective precipitation was calculated as 70%of total precipitation. Net <br /> evaporation was then computed as the difference between gross evaporation and effective <br /> precipitation. Net evaporation at the site was calculated to be 2.3 feet. <br /> Mining in proposed areas will intercept the water table. In order to allow for dry mining of the <br /> material, dewatering trenches will be constructed around the perimeter of the pit and the water <br /> pumped into the Big Thompson River. The dewatering trench will be approximately 15000 linear <br /> feet long by 5 feet wide. This will expose approximately 1.7 acres. An estimated 0.3-acre <br /> collection area will also be built at the low end of the trench for water removal Therefore, the <br /> evaporative losses at the site will only consist of the approximately 2.0 acres exposed water <br /> within the trenches and collection area(Table 1). <br /> The net annual losses due to evaporation at the Wagner/Kauffman #3 site for the mining <br /> operation are 4.6 acre-feet (Table 1). <br /> Operational Losses <br /> The water contained in the mined material is considered a consumptive use. The operator <br /> anticipates that 200,000 tons of material will be mined from the area annually. The moisture <br /> Page 2 <br />