Substitute Water Supply Plan Forum September 1 2004

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8 (most cases equal to dry -year yield). A di y year analysis shall be based on the average of 4 or 5 dry years (1954, 1963, 1977, 1994, 2002) unless such average is greater than the historical average for the entire period of record. The water court may impose less stringent conditions on the plan for augmentation based on a different study period. Any non -use of the water right during a study period shall be included in averaging historical use. Any occurrence of subirrigation must be documented and considered in the historical use analysis. Documentation of historical irrigation may be based on aerial photographs, sworn affidavits, court decrees, well permit files and water commissioner diversion records. Estimates of irrigation efficiencies, ditch conveyance efficiency, and subirrigation shall be based on acceptable engineering references and standards. 26.E The land to be dried up shall be documented to the satisfaction of the local water commissioner. A copy of the dry -up covenant and a map designating the dried -up lands shall be submitted to et -e€fEe -the Office of the State Engineer and recorded with the county clerk and recorder. Maintenance of historical return flows from the former irrigated lands will be required if necessary to prevent injury to other water rights. The timing of return flows may be calculated using Glover techniques [parallel drain theory, stream depletion factor (SDF)], or numeric modeling. 27.49- Substitute water supply plans may use reservoir water released to the stream at the proper time and in the proper amount. Reservoir storage and releases are generally required to offset winter depletions. An analysis of the consumptive use of the reservoir water (if reservoir water is not decreed for augmentation purposes) should be performed similar to that performed for a direct flow water right. Dry-up of irrigated lands will be required if the only source of water available was the reservoir water. A copy of the dry -up covenant shall be submitted to our office and recorded with the county clerk and recorder. 28.2-0- An excavation that intercepts groundwater is considered a well; thus the excavation may not be used for water storage •Y itheut f « ^t being unless the excavation is lined in accordance with the State Engineer's lining criteria or exists in an area surrounded by an impervious layer such as bedrock. See attaehed pr-eposed guidelines far- lining efAer-ia for- gm,elpit& 29.x- It may be possible to introduce water into recharge sites located at desirable distances from the stream using the sources discussed previously or water diverted when there is a free river. Water introduced into the recharge site will migrate to the stream over time. The rate of movement is a function of the transmissivity and specific yield of the alluvial material. With ideally located recharge sites, recharge water would reach the stream during all months of the year and would be creditable against stream depletions caused by the gravel mining operation. Our office must specifically approve use of these recharge plans unless the water court has previously approved the site. 30.2-2- Transportation loss charges, if applicable, will be assigned for any replacement source of water.