2006-12-12_REVISION - M1977439 - Laserfiche WebLink

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Ms. loam Comanlciu RE: Upper Poudre Rrver SYYSP Renewal September 16, 2006 Page 1 of 5 mining production rate will remain 500,000 tons of material per year with 14.7 acre-feet consumed, and the annual volume pumped for dust control will also remain 2.0 acre-feet. The total consumptive use for the Home Office Pit will remain 44.7 acre-feet (Table No. I). Overland Ponds Site The only consumptive use at the Overland Ponds Site will be evaporation, which is unchanged from the previous plan approval. The consumptive use is 5.4 acre-feet from evaporation of exposed groundwater (Table No. 1). North Taft Hill Expansion Site Evaporation from the 13-acre pond will remain the only consumptive use for the North Taft Hill Expansion Site. The consumptive use is 29.7 acre-feet (Table No. 1). Total Consumptive Use The total consumptive use from the three sites in Water Year 2007 is 79.9 acre-feet (Table No. 1). Lagged Mining Stream Depletions Table No. 1 also displays the lagged timing ofthe mining depletions which were included in previous approvals of the respective plans. There are no changes to the timing of the lagged mining depletions. Copies of the stream depletion models for all three sites aze included in Appendix B. The depletions are included in a real-time format for the Overland Ponds and North Taft Hill Expansion Sites. The equilibrium values for the Home Office Pit depletions were used due to the operation of the mine since the late 1970's. TAYLOR AND GILL DITCH Lafarge will again use 5.75 Taylor and Gill Ditch shares in this plan. The historic consumptive use credit and the accretions and depletions remain unchanged from previous renewals approved by the SEO (Table No. 2). WATER BALANCE AND REPLACEMENTS A combination of recharge of the historic use credit from the 5.75 Taylor and Gill Ditch shares and a lease from the Tri-Districts will make replacements in the combined plan. Water Commissioner George Varra has previously approved of these replacement sources for the individual plans for the three sites. Starting in Water Year 2003, Lafarge has recharged Taylor and Gill Ditch shares into an unlined rechazge site at the Home Office Pit for replacements of the mining depletions. Lafarge will again divert the 5.75 shares into the recharge site during the 2007 irrigation season. Table No. 3 shows the farm headgate delivery of 5.75 Taylor and Gill Ditch shares. Lafarge plans to divert the full farm headgate delivery of 240,3 acre-feet into the recharge site each year (Table No. 3). Appendix C includes the Water Year 2005 and 2006 accounting records of water diverted into the recharge site. Water Commissioner George Varra has received a copy of these records. Lafarge staff