2013-01-29_HYDROLOGY - M1979191 - Laserfiche WebLink

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Mr. Jared Dains Lafarge Middle Poudre Combined SWSP January 28, 2013 Page 4 of 8 existing lateral from the ditch. The 5 shares are from the group of 5.5 shares that were historically associated with the Three Bells Farm. The recharge pit was constructed on the un -mined portion of the Three Bells Pit site and it was excavated to only the upper portion of the gravel deposit and will not expose additional ground water. The estimated recharge pit size is one acre. For the purposes of this plan, evaporation from open water was assumed for the entire surface area of the recharge pit for the number of days water was diverted into the recharge pit. Based on this approach, the proportion of days with water diverted into the recharge pit to the number of days per month was applied to the monthly gross evaporation rate, resulting in an evaporative consumptive use from the recharge pit of approximately 2.04 acre -feet. Box Elder Ditch is divided into 64 Box Elder Ditch Company ( "BEDC ") shares. Lafarge owns 5.5 shares of the 6.0 BEDC shares that were historically utilized for the irrigation of the Three Bells property (344.3 acres), and are applying 5 of those shares for recharge credits under this plan. The dry-up acreage claimed for Lafarge's 5.5 shares would be 305.6 acres of the 344.3 historically irrigated acres on the Three Bells property. The historical consumptive use credit of the 5.5 BEDC shares associated with the Three Bells property was determined to be 281.4 acre -feet, based on a historical consumptive use analysis that was completed in support of an application for an augmentation plan pending in case no. 2002CW205. Table 2 shows the average ditch diversion for the Box Elder Ditch from 1950 to 2007. Table 3 takes the average ditch diversions for the Box Elder Ditch from 1950 to 1984 and analyses the historic consumptive use and return flows for Lafarge's Three Bells Farms 5.5 shares. Table 4 breaks this information down further to come up with the historic farm headgate diversions and return flows for the 5 BEDC shares to be used in this plan. As shown on Table 4, the average farm headgate diversions associated with the subject 5 BEDC shares is 457.0 acre -feet and the associated return flow obligations will total 201.1 acre -feet. This leaves a net consumptive use credit of 255.9 acre -feet, or 51.2 acre -feet per share. In 2012, Lafarge diverted a total of 269.84 acre -feet into the recharge site associated with these five shares. Lafarge is projecting to deliver the average headgate diversion 457.0 acre -feet into recharge for 2013. Accordingly, the monthly timing of 457.0 acre -feet (full farm headgate delivery of the 5 shares) was used in the recharge model to determine the recharge accretion credits for 2013. The recharge model uses the following parameters: transmissivity (T)= 45,000 gallons /day /foot, the distance of centroid of the recharge pit to the Cache La Poudre River (X) =1,600 feet, the distance for the parallel impermeable boundary to the Cache La Poudre River (W) =5,000 feet, and the specific yield (S) =0.2. The lagged accretions to the Cache la Poudre River are estimated to total 429.85 acre -feet for this approval period (includes carry over from recharge in previous years). Actual recharge credits and return flow obligations will be based on the actual deliveries made for replacement purposes in this SWSP. As shown on Table 5, recharge credits from the 5 BEDC shares are not sufficient in January through June of 2013. These deficient months will be covered through leases with LCRC and Aurora. The Aurora lease will be used January through March, and the LCRC lease will be used April through June. Since the LCRC lease has not yet been finalized this SWSP will expire at the end of March 2013 but will be automatically extended till December 31, 2013 should this office be provided with a copy of the signed lease between Lafarge and LCRC by March 31, 2013. A lease of 29.2 acre -feet of fully consumable water provided by the City of Aurora ( "Aurora ") will be used to make replacements during the non - irrigation season of January 2013 through March 2013. The releases will be made from the Metro Waste Water Reclamation Facility (WDID 0200700) located in Denver on the South Platte River approximately 66 miles upstream from the Cache la Poudre confluence. Therefore a 16.5% (0.25% per mile) river transit loss will be assessed on all deliveries. During the winter it is possible for a call to be placed on the Evans Number 2 ditch for a Milton Reservoir call, or a call at the Western, either of which could potentially sweep the river. It is the Applicants