2010-08-05_HYDROLOGY - M1980135 - Laserfiche WebLink

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a) Beginning in 2007, UPBCC installed a meter on all the existing irrigation wells that are included in its plan for augmentation, including the Booth Farm Well. From 1974 to 2006, monthly pumping volumes under the Booth Farm Well Right were estimates included as part of annually approved substitute water supply plans submitted by GASP to the State Engineer. Based upon these data, the average annual volume of water pumped from the Booth Farm Well is 135 acre-feet. b) Return flows resulted from the portion of historical irrigation water deliveries under the Booth Farm Well Right that were not consumed by the crops. Because the well provided a supplemental irrigation source, the actual rate of consumption of these deliveries equaled the application efficiency on the farm. Because the farm was flood irrigated, an application efficiency of 60 percent is reasonable, and identical to the value used to estimate the well water consumptive use for the UPBCC Augmentation Plan. Therefore, return flows comprised the remaining 40 percent of the volume pumped from the well. c) Historically no water left the farm as surface flow. Therefore 100% of the return flows from irrigation historically accrued to the river as groundwater flow. To maintain the historical pattern of return flows in the future, Pinneo will multiply the volume of water pumped from the Booth Farm Well, which is delivered via existing laterals on the Booth Farm and subsequently measured at the Booth Farm Recharge Ponds, by the applicable 40% return flow factor to determine the unlagged return flow obligation. Because the Booth Farm Recharge Ponds is located in the area historically irrigated by the Booth Farm Well, the timing of the accretion of the return flow obligations will naturally match the timing of historical return flows. This method of handling return flow obligations will limit the consumptive use credit consistent with the methodology and assumptions used for the Booth Farm Recharge Ponds. Thus, the net credit at the river from recharge at the Booth Farm Recharge Ponds will simply limit credit for the Booth Farm Well Right water to no more than 60% of the pumped volume. For ease of accounting, during the periods of time when water from the Booth Farm Well Right is being delivered to the Booth Farm Recharge Ponds for augmentation purposes, no other irrigation water will be used on the Booth Farm from UPBCC shares, Jackson Lake Rights or other sources of irrigation water. d) Accordingly, future pumping and use for augmentation and replacement purposes of the average annual amount of water historically pumped and consumed under the Booth Farm Well Right (i.e., 135 and 81 acre-feet per year, respectively) will not expand the historical consumptive use of that water right, if future pumping occurs pursuant to the terms and conditions of this decree. 17 of 33