WSP02949 - Laserfiche WebLink

Home Browse Search

ANNUAL OPERATING PLAN FOR WATER YEAR 1999 Three operation studies were developed for the Project to establish an AOP for water year 1999. Each of the studies conformed to the established operating criteria but used differing inflow conditions and water demands. The three inflow conditions were determined from a probability analysis of historic monthly inflows and are labeled reasonable minimum, reasonable maximum, and most probable. Reservoir inflow during water year 1999 has a one-in-twenty chance of being less than the reasonable minimum and a one-in-twenty chance of being greater than the reasonable maximum. Statistically, inflows in 1999 will have an nine-in-ten chance offalling between the two extremes. The most probable inflow is based on long-term averages and approximates a 50 percent chance of occurrence. The three studies for water year 1999 are summarized numerically in tables SA, 5B, and 5C and graphically in exhibits 4 through 9. The annual operating plans for Green Mountain Reservoir are also summarized in table 6. The AOP, as developed and reflected in the three studies, provides the flexibility to adjust operations as conditions change during the water year. Forecasts of the April-July reservoir inflow will be made at the beginning of each month from February through June. The majority of snowmelt runoff occurs in the April-July period. Projected operating schedules will be adjusted, as required, throughout the water year as changes occur to the forecasted inflows, irrigation demands, maintenance schedules, and power loads. October-Janwuy Period The three studies for the October-January period of water year 1999 are similar because winter inflows are nearly the same under the three conditions of inflow. The most probable inflow condition is utilized for the 1999 October-January Project operations and is summarized in the following paragraphs. Operations for this period reflect scheduled maintenance on several powerplants and other project features. Green Mountain Reservoir Green Mountain Reservoir began the water year with 128,725 acre-feet in storage, which was -HB percent of the 1966-1995 average. Releases for bypass of inflow and CBT Project replacement will continue into October. Little depletion by Colorado Springs and no depletion by Denver is expected until next runoff season. Releases from Green Mountain Reservoir for replacement, bypass of inflow, power, and river and reservoir operations are expected to average 34G ft'/s during the November-January period. These releases will lower storage to about 89,690 acre-feet by January 31. filename: CBTAOP9B.DFT 19 Pr<liminary Woridng DradJuIy 1.1999