Subordination of the Wayne N. Aspinall Unit Water Rights within the Upper Gunnison Basin: Annual Report (2)

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TABLE 1 (continued) PROCEDURE TO ESTIMATE DEPLETIONS AND DIVERSIONS Code Structure Type of Use Procedure used to Estimate Diversions and Depletions 1) 2) (3) (4 Ev Reservoir Reservoir evaporation Diversions and depletions equal to reservoir evaporation losses. (Note: If with rights in is primary use measured diversions are available, the measured diversions are reported - See units of acft Dv1 code.) Reservoir evaporation loss estimated as 5.6% of the reservoir storage right. The factor of 5.6% was determined from an analysis of 24 reservoirs with available reservoir surface area. For these reservoir the total reservoir evaporation losses were estimated as the reservoir surface area multiplied by the reservoir evaporation rate. This loss is then pro -rated between water rights using the decreed storage amounts. The reservoir surface area is obtained from the DWR GIS information (CDSS website) that tabulates maximum water surface area. A net evaporation rate of 2.23 feet is estimated from the average of the net evaporation rates at Taylor Park Reservoir and Blue Mesa Reservoir (see the Division 4 Engineer Accounting for Taylor Park Reservoir and Blue Mesa : Reservoir). Ir1 Non- Irrigation with no Depletions and diversions are zero because this structure was determined to Reservoirs irrigated acreage and have no irrigated acreage by the DWR as documented in the DWR irrigated no DWR diversion acreage data in the DWR HYDROBASE. In addition, the DWR HYDROBASE records showed zero ao-ft of diversion for this structure. Ir2 Non- Irrigation with no Diversion records from DWR HYDROBASE. The DWR estimated no irrigated Reservoirs irrigated acreage but acreage associated with structure. Depletions are estimated to be 18% of the DWR diversions diversions based on the depletions percentage for junior irrigation rights in records StateCU (0.18= 2,732/15,553). Ir3 Reservoirs Irrigation with DWR Records of diversion to storage, release from storage, and evaporation losses records available from the DWR HYDROBASE. These records indicate that in 2001, all of the diversions to storage were under water rights senior to the Aspinall unit water rights. This coding is used for Vouga Reservoir, Upper McDonough Reservoir, and Lower McDonough Reservoir. Ir4 Reservoirs Irrigation with no No records of diversion, release or storage available from the DWR DWR records HYDROBASE. Based on engineering judgment it is estimated that 50% of the water right was diverted into storage and 30% of the water diverted to storage was consumed for irrigation purposes. I1`5 Reservoirs Decreed for Irrigation This code applies to Spring Creek Reservoir. This reservoir is decreed for but no longer used for irrigation but is no longer used for irrigation purposes. Therefore, the irrigation Irrigation diversions and depletions are z ero ac -ft LGr Reservoir Lake Grant Reservoir Applies only to Lake Grant Reservoir (Structure Id 593684). DWR recorded diversions equal to 133 ac -ft at this structure. These diversions are used to irrigate a golf course. The diversions are recorded at this structure but diversions are not made under the Lake Grant storage right. Therefore, only diversions and depletions from reservoir evaporation are shown. Meek Ditch Transbasin Applies only to Meek Diversion Tunnel (Structure Id 400576). Diverts water out of Crystal creek into the Smith Fork Basin. All of the diversions are exported out of the Aspinall Unit drainage area; therefore, 100% of the diversions are considered consumed. Mn Wells Municipal Diversions records reported in the DWR HYDROBASE. For the purposes of this study it is estimated that depletions are 36% of diversions (value used by StateCU ). Ot Non- Other Diversions and depletions are estimated at 0.44 acft which is the value Reservoirs estimated by the Division 4 Engineer for other water rights when no additional information is available. Sn Pipeline Snowmaking Applies only to Crested Butte Mountain Resort (CBMR) snowmaking water right (Structure Id 591362). Diversions of 218 ao-ft from CBMR records. Depletions estimated to be 20% based on other water right transfers involving snowmaking water rights. Helton & Williamsen, P.C. Page 6 2001 Annual Report.xls, Table 1, 12/18/2002, rlh