Consistent, accurate and detailed information on water consumption by agricultural crops has been a long standing critical need in river and water resources management. Quantification of consumptive use (evapotranspiration-ET) is increasingly important as water resources are placed under growing tension by increased users and interests. Scarce water supplies can be managed more efficiently through use of comprehensive real-time information and prediction tools, and accurate and timely information. Crop ET is a large component of the water balance in agricultural areas of the arid west. The focus of the proposed work is to develop multi-temporal and spatial scale ET application prototypes to augment decision support capabilities and increase operational efficiencies of two water management decision support systems, SPDSS and RiverWare. The proposal describes a method for estimating real-time ET demand using NASA Earth-Sun system research results. The proposed methodology solves the surface energy balance equation using the reflectance and temperature bands of satellite imagery and provides instantaneous ET estimates on a pixel-by-pixel basis, which are in turn related to an instantaneous reference estimation from a weather station. Based on this relationship weekly, monthly and seasonal ET estimates can be computed for each pixel and aggregated by area, crop type, or diversion structure. Prototype applications will be developed in two locations: Colorado (SPDSS), and Washington State (RiverWare). Benchmarking evaluation tests will be developed and implemented to identify, measure and report the degree of enhancement afforded to the respective DSS. An internet map serving and analysis capability will be developed by RTi to streamline the flow of data into both DSS. Numerous activities throughout the grant period will be aimed at systematically building a transition approach that guarantees the enhanced DSS has life beyond NASA support. Extension of the DSS enhancements will be facilitated by partnerships developed with agricultural-water management extension agents regionally, nationally and internationally.