7886 - Laserfiche WebLink

Home Browse Search

Reservoir Operating Studies It is anticipated that some drawdown restrictions might be placed on the enlarged Elkhead Reservoir to maintain summer recreation potential. While the model incorporates options to simulate such restrictions, none were imposed in the final operating studies of the enlargement. A review of model results indicated that the recreational pool target levels were met most of the time without imposition of these operational restrictions. EARLY OPERATING STUDIES Studies of the Juniper Contemplated Draft The Contemplated Draft of the 1954 Juniper water rights was estimated by implementing the water rights and operation of the original Juniper Project in the basin model. The water rights represented included the Deadman Bench Canal direct flow right for 550 cfs, the hydropower direct flow right of 1,000 cfs, and the storage right for 825,294 of (the original storage decree. for 844,000 of was reduced by 18,706 of to reflect previous transfers). Juniper Reservoir was modeled with a total capacity of 844,000 of including dead storage of 73,226 af. Two scenarios were defined to obtain preliminary estimates of the Contemplated Draft. In the first, the Juniper rights were operated in their correct priority position; in the second, the Juniper rights were operated in a subordinated priority position, junior to all current demands. ' Common to both scenarios was the use of the "current potential" demand level. Based on the first of these scenarios, if the original Juniper Project were in existence today and operated using its 1954 water rights without regard to any specific or general subordination, the total draft of the Juniper rights would average 863,524 of per year. On the average, about 96,000 of of this draft is due to direct flow diversion through the Deadman Bench Canal and 339,910 of from direct flow diversion for hydroelectric power generation; the remaining 427,538 of is diverted to storage in Juniper Reservoir. The annual draft of the Juniper Project ranges from a high of 1.23 million acre-feet (maf) in 1978 to a low of 0.34 maf in 1977. There are substantial water shortages throughout the basin in this model scenario as the Juniper rights call out many existing juniors, including the existing reservoirs. More detailed results of this model scenario can be found in Appendix B. In the second scenario, with the Juniper Project water rights subordinated to all other demands in the basin, the total annual draft of the Juniper rights averages 856,529 of per year. On the average, about 91,000 of of the draft is due to direct flow diversion by the Deadman Bench Canal and 324,343 of from direct flow hydroelectric power generation; the remaining 441,255 of of the draft results from storage in Juniper Reservoir. The annual draft of the subordinated Juniper Project ranges from a high of 1.29 maf in 1962 to a low of 0.32 maf in 1977. Shortages to basin demands are much lower in this scenario than with the Juniper Project operated with an unubordinated 1954 priority and are not caused by a call of the Juniper rights. This finding is consistent with Division 6 data indicating that current use by water rights junior to the Juniper rights is substantially less than the 65,000 of allowed under the general subordination. More detailed results of this model scenario can be found in Appendix C. 1 2-9