IBCC Meeting Notes Feb 2 2007 - Laserfiche WebLink

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within the state the maximum amount of flexibility in deciding how to manage the se water resources. Gauged river flows and calculations of Colorado’s current consumptive use indicates that Deleted: use indicates between 450,000 ac - ft and 1,200,000 ac - ft of Colorado River water may be remaining in the river and its tributaries . The lower end of the estimate ta kes into consideration water that is available under a multiple year drought (i.e., firm yield approach). The upper end of the estimate reflects the maximum legal availability to Colorado under the Colorado River compact. Brown Deleted: compact . stressed that all water rights are subject to legal and physical availability. He also pointed out the differences in water accounting between the Colorado and other compacts – noting that the Deleted: other compacts Colorado compact accounting is based on a 10 - year running averag e. Questions and Discussion IBCC members and CWCB staff spent significant time discussing issues related to the river compacts, and pending legislation that would fund a CWCB study of the Colorado River. Comments made are presented below grouped by di scussion topic, and in the order in which the comments were made while discussing that topic. Feedback on Presentations ? Eric Wilkinson : I agree with the three questions Eric Kuhn proposed. We need to do engineering studies to get more information, an d address the important policy questions that need to be answered and decisions that need to be made. If hydrology is indeed changing, and the past is not a predictor of the future, we need to do studies that will help us make an educated guess at future conditions. Firm yield versus average yield is a question of risk tolerance and engineering management. Several factors have contributed to what happened on the South Platte. If the South Platte had used firm yield to make decisions, development would have stopped in 1900. However, the decision was made to allow appropriation based on average yield, and infrastructure was built to make that possible. The storage to yield ratio on the South Platte is high. I agree that how a compact call on the Col orado River will be administered is one of the key questions. Will it be apportioned among all four upper basins? Will junior users be curtailed? These questions must be answered before you can do a risk analysis. The decisions that were made on the South Platte were based on administration as we understand it, and we need to understand how administration works or will work on the Colorado. We must undertake three steps before permitting more development of the Colorado: studies to better understand future hydrology; clarification of what will happen if there is a compact call; and a risk analysis of development scenarios, considering legal and physical availability of water in the basin. 11