2002-06-17_GENERAL DOCUMENTS - M1979097

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The updated diversion records and the new consumptive-use credit were used to determine the historic accretions and depletions for the 8.0 Box Elder shares that were used in the original substitute supply plan for East Ridgen and the other two'sites (Table No. 3): These values were then,pro-rated and used to calculate the accretions and depletions for the 3:0 shares pioposed in this renewal for the East Ridgen property (Table No. 3). The historic subsurface return flows associated- with [he 8:0 Box Elder Ditch shares were modeled using a stream depletion model for the land historically irrigated with these shares. This property is no longer irrigated due to mining. The return flows accruing to the Cache la Poudre River were niodele8 under the following assumptions: ~ The centroid of the East Rigden property formerly irrigated with the Box Elder shares is approximately 2400 feet from the Poudre River. •. The transmissivity was assumed as 55,000 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. B7-68-22aba2 (Appendix A). • 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 5800 feet from alive stream. Source: USGS Depth to the Watei• Table in the Boulder-Fort Collins-Greeley Area, Front Range Urban Corridor, Colorado. The return flow analysis is-included in Appendix B for your review. The historic irrigation credit and return flow obligations are presented in Table No. 3. The consumptive use credit for these shares has been approved iri the previous renewals. REPLACEMENT-WATER This renewal will utilize four replacement sources. These include the 3.O Box Elder shares returned to the river wilt make summer replacements, I.0 share of the Bok Elder Ditch will 6e recharged from the East Rigden site to make replacements throughout the year, the Rigden Flume water right will make replacements December through March, and a lease from the City of Fort Collins will make replacements during the remaining months. As in previous renewals, the 3.0 Box Elder shares used as direct replacement during the irrigation season will be left in the ditch and returned to the Poudre River where the Water Commissioner will account for it. Page 4