2017-03-02_HYDROLOGY - M1977436 - Laserfiche WebLink

Home Browse Search

South Platte Combined Replacement Plan March 1, 2017 Page 6 of 19 The consumptive use and lagged stream depletions from each site are summarized in the attached "South Platte Combined Substitute Supply Plan Accounting 2017" sheet. Replacements Lower Poudre River Projected Replacement Sources 2017 Yield Comments (acre-feet) Whitney Ditch 170.93 13.5 shares L.G. Everist lease 32.00 Annual lease Note: Projected 2017 yield may vary from previous estimates of net yields due to the computed return flow obligations based on the previous year's actual water deliveries. Whitney Ditch Aggregate owns a total of 13.5 shares in the Whitney Ditch Company. The subject 13.5 shares were changed in case no. 90CW23 from irrigation use to industrial mining, dust suppression, reclamation, irrigation, augmentation under the plan for augmentation described in the decree, and piscatorial purposes. The use of the subject shares for replacement purposes in this SWSP was not decreed in case no. 90CW23; however, the Applicant has proposed to use the subject shares for replacement purposes pursuant to this SWSP in conformity with the requirements of case no. 90CW23. The decree entered in case no. 90CW23 relied on a ditch -wide analysis of the Whitney Ditch developed for and decreed in case no. 08CW65. Based on a study period of 1950 through 1995, the Court found that the average annual gross river diversion was 10,600.2 acre-feet per year or 33.13 acre-feet per share. The ditch -wide analysis determined that the overall average consumptive use was 4,400.9 acre-feet per year or 13.75 acre-feet per share for 320 shares, assuming a system loss of 15% and a farm efficiency of 60%. In case no. 02CW331, 8 shares historically used on 74 acres were found to have a river headgate diversion of 33.42 acre-feet per share and a consumptive use of 16.32 acre-feet per share (130.5 acre-feet total). After removing the consumptive use decreed for the 8 shares in case no. 02CW331, the historical consumptive use for the remaining 312 shares was determined to be 4,270.4 acre-feet, or 13.69 acre-feet per share. For Aggregate's 13.5 Whitney Ditch shares, the total average annual consumptive use would therefore equal 184.81 acre-feet per year. The ditch -wide analysis utilized a return flow split of 50% surface and 50% subsurface return flows. For the 2017 plan period, Aggregate will dedicate ail 13.5 of their Whitney Ditch shares to this SWSP. For the purposes of this SWSP, the projected consumptive use credit has been estimated based on a dry -year farm headgate delivery of 24.75 acre-feet per share (which includes a 15% ditch loss) or approximately 334 acre-feet for all 13.5 shares. After accounting for the return flow obligations, the total consumptive use credit for 2017 is projected to be approximately 172 acre- feet. Beginning in 2011, Aggregate utilized the return structure owned by the Whitney Irrigation Company located in the SEI/4 of Section 30, Township 6 North, Range 66 West, 6th P.M. Aggregate anticipates that this return structure will be utilized again in 2017. A copy of the agreement authorizing Aggregate's use of this structure for the 2017 irrigation season is anticipated to be available after mid-February. This source may not be used until the Applicant has provided an executed agreement. Office of the State Engineer 1313 Sherman Street, Room 821, Denver, CO 80203 P 303.866.3581 www, water, state. co. us