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.~~, ~'. ! S t. ;..,,' ~: _.) -"- -_~ d. ..' . System (CRSS) and Colorado River System Consumptive Uses and Losses Report (CU&L) irrigation depletion rate estimates. Rates developed for the upper Uncompahgre, Lower Uncompahgre, smith Fork/North Fork, and Lower Gunnison areas of the Gunnison basin were used for expanded network flow development. Irrigated acreage and depletion rates as used in deriving natural inflows for the "expanded network" (Uncompahgre, Smith Fork/North Fork, and Lower Gunnison mainstem) portion of the model were provided to Hydrosphere. Acreages and depletion rates were used to define agricultural demands in the model. the irrigated acreage figures were considered the best estimates available, pending completion of the GIS irrigated acreage inventory being done by the Remote Sensing section in conjunction with the State Engineer's Office. . at the time that depletion rates were provided to Hydrosphere, it was noted that these rates include adjustments for incidental use and shortage conditions. Inclusion of such adjustments was appropriate for use in natural flow development, but should not be included in modeling irrigation demands where it is "up to the model" to compute shortages for varying demand and hydrology conditions. These rates were used in Hydrosphere's Beta test version of the model as place holders to facilitate the debugging process. The rates provided to Hydrosphere are listed in Table d. Plots of annual ('52-'90) rates for the Upper Uncompahgre, Lower Uncompahgre, Lower Gunnison, and Smith Fork/North Fork areas are shown on Figures 1-4. Hydrosphere has requested depletion rates with incidental use and shortage adjustments backed out (base Blaney-Criddle c.u. rates) and/or supporting information covering cropping pattern, climate data, incidental use, etc., assumptions applied in depletion development. They would like to use these rates for the next Beta test and final model releases. USBR Denver Office personnel have provided depletion rates with incidental use and shortage adjustments removed (See Table ~). Plots of annual consumptive use rates (' 52- '90;adjustments removed) for the Upper Uncompahgre, Lower Uncompahgre, Lower Gunnison, and Smith Fork/North Fork areas are shown on Figures 5-8. . During the first beta testing period, one of the testers questioned the apparent upward trend in Lower Gunnison depletion rates (see Figure ~). This trend is not apparent in the "adjustments removed" rates (Figure .lU . .. A drop appears in both adjusted and "adjustments removed"