Adjusting Supply and Demand: Technical Analysis to Support the ESPA Management Plan Idaho Water Resource Board Meeting May 17, 2007

Technical Study Tasks Staff has identified 18 technical tasks to be undertaken in support of the ESPA Comprehensive Aquifer Management Plan. Additional tasks could be added if needed. The tasks are not listed in any preferred order.

Task No. 1 - High Lift Exchange Water Availability This would involve acquiring “high-lift” water rights below Milner Dam and using this water to exchange with water being released from Upper Snake reservoirs by the Bureau of Reclamation for flow augmentation. The exchanged water could then be delivered to recharge or to conversion projects.

Task No. 2 – Quantify Excess Flow Past Milner Dam This would quantify the excess flow past Milner Dam that is not being delivered for a specific purpose. This would be done both constrained and unconstrained by the Milner Dam hydropower water right. Currently, aquifer recharge would be junior to the Milner hydropower right, but new surface storage would be senior to the Milner hydropower right.

Task No. 3 – Quantify Excess Flow in Wood Rivers Basin This would quantify the excess flow in the Wood Rivers Basin available for aquifer recharge.

This would involve acquiring surface water (high-lift exchange, new storage, rental pool, etc.) and delivering it into canal systems with large numbers of supplemental wells. This added supply could then offset the use of the supplemental wells. Task No. 4 – Soft Conversion Projects

Task No. 5 – Hard Conversion Projects This would involve acquiring surface water but would require construction of new infrastructure to deliver the surface water into areas that only have ground water supplies, such as the A&B Irrigation District.

Task No. 6 – Surface Water Storage Alternatives in Upper Snake Basin Review past studies of potential reservoir sites in the Upper Snake Basin, index the costs to current levels, and identify any fatal flaws. The stored water could be delivered to conversion projects or to offset shortages.

Task No. 7 – Additional Payette Rental Pool Use Evaluate making additional use of the Payette Basin Rental Pool to supply flow augmentation, reducing the burden of the Upper Snake Rental Pool to provide flow augmentation. This could free up water in the Upper Snake that could be delivered to conversions, recharge, or shortages.

Task No. 8 – Surface Water Storage in Southwest Idaho Basins Review past studies of potential reservoir sites in the Boise, Payette, and Weiser Basins, index the costs to current levels, and identify any fatal flaws. The stored water could be used to reduce the burden of the Upper Snake Rental Pool to provide flow augmentation, freeing up water to be delivered to conversions, recharge, or shortages. Could also provide local benefits within these basins.

Task No. 9 – Aquifer Recharge Evaluate the amount of recharge that can be accomplished and the costs of facilities needed to accomplish recharge.

Task No. 10 – Thousand Springs Water Management Projects A number of potential projects in the Thousand Springs have been identified. Evaluate these projects, index costs to current levels, determine amount of water that could be gained, and willingness of owners to participate. Evaluate feasibility of constructing flowing artesian wells.

Task No CREP CREP is underway but will be part of the overall plan. Evaluate effects of CREP on aquifer. Task No. 12 – Evaluation of Crop Mix Changes on Consumptive Use of Water Analyze changes to ESPA water budget from changes in cropping patterns on Eastern Snake Plain.

Task No. 13 – Evaluate Potential Impacts of Climate Change on timing and Magnitude of Surface Flows in Upper Snake Basin Climate change may impact the amount and the timing of surface runoff in the Upper Snake. Task No. 14 – Weather Modification Evaluate the potential for weather modification (cloud seeding) to be a part of the overall plan.

Task No. 15 – Evaluate Water Right Purchases in Upper Snake Evaluate costs and willingness of owners to sell existing surface water and ground water rights in the Upper Snake Basin.

Task No. 16 – Generate Alternatives Combine various options into several alternatives based on cost effectiveness, water budget response, and political acceptance Task No. 17 – Economic Analysis Analyze benefits and costs of alternative plans Task No. 18 – Preferred Plan Select preferred plan based on economic analysis of alternatives, water budget response, and advisory committee recommendations

Questions ?