2009-12-22_HYDROLOGY - M1977436 - Laserfiche WebLink

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Jared Dains Page 6 South Platte Combined Replacement Plan December 21, 2009 Whitney Ditch Five of the shares of Whitney Ditch were historically used to irrigate 65 acres consisting of 65% corn, 30% alfalfa and 5% beans. Using a Blaney - Criddle analysis the potential crop consumptive use for the 65 acres'was determined to be 96.8 acre -feet. Assuming a 10% ditch loss and 55% farm efficiency the dry year consumptive use was determined to be 64.3 acre -feet. Six of the shares of Whitney Ditch were historically used to irrigate 57.1 acres of pasture grass. Using a Blaney - Criddle analysis the potential crop consumptive use for the 57.1 acres was determined to be 96.8 acre -feet. Assuming a 15% ditch loss and 60% farm efficiency the dry year consumptive use was determined to be 84.64 acre -feet. The 2.5 shares of the Whitney Ditch were historically used for the irrigation of 24 acres. A total of 40 shares of the Whitney Ditch were recently changed in case no. 2002CW390 that was approved by the water court on September 26, 2007. As in case no. 2002CW390, this plan will estimate ditch loss to be 15 percent, a maximum farm irrigation efficiency of 60% will be used, and a return flow split of 50/50 between surface and subsurface return flows will be used. The total net consumptive use available for the dry-up of this 24 -acre property is 37.3 acre -feet. For 2010, the applicant will utilize 12.5 shares out of the 13.5 Whitney Ditch shares. The expected consumptive use credit for the 12.5 Whitney Ditch shares has been estimated from a dry-up farm headgate delivery of 24.75 acre -feet per share (which include the 15% ditch loss) or approximately 309 acre - feet for the 12.5 Whitney Ditch shares. After accounting for the return flow obligations the total consumptive use credit for 2010 is projected to be approximately 211.61 acre -feet. This value is greater that the estimated dry-year yield because Aggregate owns lower than normal return flows in 2010 due to the small volume of deliveries made in 2009 (only approximately 109 acre -feet were delivered in 2009). The Whitney Ditch shares are measured and returned to the river at an existing structure located in the NW1 /4 of Section 33, Township 6 North, Range 66 West. For accounting purposes the return flow requirement for the Whitney Ditch will be determined based on the calculated return flow factors. You indicated that Aggregate has repaired the augmentation station for the Whiney Ditch and the augmentation station has been approved and utilized by the water commissioner. Boyd & Freeman Ditch The 240 Boyd and Freeman Ditch shares were historically used to irrigate 85 acres of pasture grass. Using a Blaney - Criddle analysis the potential crop consumptive use for the 85 acres was determined to be 142 acre -feet. Assuming a 10% ditch loss and 55% farm efficiency the dry year consumptive use was determined to be 99.28 acre -feet. The applicant will utilize all 240 shares in this plan. Before any credit can be taken for the Boyd & Freeman Ditch, accurate measuring and recording devices must be installed and those devices must be approved by George Varra, the District 3 Water Commissioner. You indicated that the Ditch Company will decide at the next annual board meeting in December /January whether to install an augmentation station on the ditch prior to the 2010 irrigation season. If the Boyd & Freeman augmentation station will not be installed Aggregate will request more water from the City of Greeley and the Boyd and Freeman shares will not be used for replacement purposes during this plan period. City of Greelev Lease The Applicant has leased 53.34 acre -feet of fully consumable replacement water from the City of Greeley ( "Greeley "). As mentioned above, if the Boyd & Freeman augmentation station will not be