2003-08-13_REVISION - M1979191 - Laserfiche WebLink

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REPLACEMENT WATER In previous renewals, .the replacements for this site have been from a combination of direct replacement of 1.0 Box Elder share during the summer months and ]ease from the City of Fort Collins during the winter months. Now; 5.0 Box Elder Ditch will now be diverted irifo a recharge pit instead of direct replacement. Leases from the Cities of Greeley and Fort Collins will made . replacements for depletions not covered by the rechazge program. Structures -Used for Recharge Lafarge constructed a recharge.pit,on an unrnined portion of the permitted area of the DMG . boundary of the Three Bells site. The recharge pit was excavated to only the upper portion of the gravel deposit and did not expose additional ground water, so no additional evaporative loss will occur. Water is delivered to the rechazge pit through an existing lateral from the ditch. Augmentation by Recharge. The Three Bells and Kyger Properties will obtain replacements from diverting 5.0 Box Elder shares into a rechazge pit. A recharge model was used to determine the timing of the lagged consumptive use credit from the shazes as it reached the Poudre River. A copy of the recharge model run is included in Appendix B. The recharge model was developed_usirig the following assumptions to model the historic consumptive use credit reaching the Cache la Poudre River. • The centroid of the recharge pit is approximately .1600 feet from the Poudre River. • The transmissivity was assumed as 45,000 gal/day/ft. This value was assumed to be the same as the transmissivity of a pump test well in the area. Source:. Groundwater Circular No. 11, Loc. B6-6Z-18dba (Appendix B). • The specific yield was assumed to be 0.2, which is typical for an alluvial aquifer. •, The location of the parallel impermeable boundary was assumed to be a distance of 5000 feet from a live stream. Source: USGS.Depth to the Water Table in the Boulder-Fort Collins=Greeley Area, Front Range Urban Corridor, Colorado. Table No. 3 summarizes the water balance for the augmentation plan based on the results of the recharge model run for 2003. Per the requirement by the SEO, this plan will-only use real-time_ historic use credit realized by the river during the 2003 season. Table No. 3 shows the real-time stream depletions from the mining operation as well as the real-time replacements made by the lagged timing of the historic consumptive use credit- _ Page 3