Application of water rights priority and natural priority orders to river and reservoir operation systems

Abstract

Surface water rights in Texas are developed based on “Prior Appropriation Doctrine”. The Texas Water Availability Model, a computer-based simulation model based on water rights priority order, has been used for computing the amount of water supply and determining the amount of water available for a newly requested water right for the past several years. This study compares the water rights priority and natural priority orders by applying it to the largest sixteen reservoirs in the Brazos River Basin, Texas. The water supply reliability, reservoir storage frequency, and stream flows are analyzed corresponding to each priority orders. The natural priority order increases water supply reliability for most reservoirs about 1 to 2% and mean reservoir storage volume located in the upper basin than water rights priority order. The stream flows based on water rights priority order are more regulated than natural priority order by 3 and 5%. The composite priority order is more effective than each priority order in increasing the water supply reliability.