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" 001265 . . Draft Task 7 Technical Memorandum in 1934 when accessible contracted storage water had been fully depleted. Modeled future agricultural demands do not have access to reservoir storage. Shortages to the long-term (2040-level) demands averaged 537 af per year (Figure 5). The majority of these shortages occurred to Craig area agricultural demands and also to the demand representing the proposed coal-gasification plant. This plant has been located in the Craig area for modeling purposes and was not given access to storage water in the model. Occasional minor shortages also occur to other Craig area demands including municipal, mines and power uses. Reservoir Contents Reservoirs generally stay full in Scenario I with the exception of modeled seasonal drawdown operations (Figure 6). Stagecoach Reservoir and Steamboat Lake exhibit seasonal fluctuations in contents which were unrelated to downstream water demands. These seasonal fluctuations were a result of modeled efforts to minimize spills, or in the case of Steamboat Lake, to make augmentation releases during the months of August and September. No such drawdown operations occur at Elkhead Reservoir. In the long-term demand level model run, the maximum drawdown of Stagecoach Reservoir was approximately 13,500 af, which occurs during September of 1934 (Figure 6). Storage contracts in Steamboat Lake were largely unused with a maximum drawdown of approximately 3,300 af after augmentation releases have been made. Contracts in Elkhead Reservoir were the most extensively used but were drawn on only in the driest years. Elkhead was drawn down approximately 9,600 af during the fall and winter months of 1934. SCENARIO II. CONVERSION OF JUNIPER RIGHTS ONLY. Key Assumption of Scenario Many of the modeling assumptions were identical throughout all model scenarios. There were often only slight changes necessary in the model to represent a completely different set of institutional or operational rules. The only difference between Scenario I (no action) and Scenario II was the inclusion of the Juniper Project water right. This right was modeled at Juniper Canyon as an instream flow right equal in magnitude to the Juniper Project contemplated draft. The priority date of the right was modeled as 1954. The amount of the contemplated draft was defined in an earlier study (Wheeler, 1989) and averages 862,000 af per year. As defined in this Scenario II, the instream flow right cannot callout the filling of existing reservoirs or the baseline (maximum 1989) demands. The instream flow right was able to callout all existing junior and future demands in this scenario. The contemplated draft was quantified in the Wheeler study using the results of the U.S. Fish and Wildlife Service HYDROSS model. The basin model used in this Feasibility Study incorporated several assumptions that were different than those used in the HYDROSS model. This resulted in concerns over the appropriateness of using the Wheeler predicted Juniper Project contemplated draft as an instream flow in the present model. A sensitivity analysis was conducted in order to establish the effect of the magnitude of the contemplated draft on regional water deliveries. This sensitivity analysis involved increasing and decreasing the contemplated draft by 5 % and then comparing the resulting demand shortages to the same model run using the original contemplated draft. 10 i.