The primary purpose of this report is to project potential crop production levels for irrigated agriculture in Colorado. This report estimates the gains in water supply that could be achieved by improving the efficiency of water use on currently irrigated lands. For this purpose, improved irrigation management, ditch lining, and new irrigation systems were considered as means of increasing water use efficiency in agriculture. The state of Colorado was divided into eight regions for purposes of this study. These regions correspond to river subbasins within the state.