Grand Canyon March Flows
I noticed that RRFW didn't post a Glen Canyon update this month and I was doing the research for my own trip (3/5) and thought I'd post the results. The best part is that for the first 2 weeks we'll have no tide! They're fixing that piece of shit dam and will have to release a constant 16,000 CFS until mid-March to meet their water demands!
Glen Canyon Dam / Lake Powell –As of February 15, 2011, unregulated inflow to Lake Powell is trending towards a February monthly volume of 314 kaf (75% of average). The monthly volume of unregulated inflow to Lake Powell that was forecasted at the beginning of February by the Colorado River Forecast Center (CBRFC) was 350 kaf (83% of average). Releases from Glen Canyon Dam are currently averaging about 18,000 cfs and this is well above the rate of inflow that Lake Powell is currently receiving. For this reason, the elevation of Lake Powell will likely decline by about 5 feet during February to an elevation of approximately 3615 feet above sea level. This condition is likely change in March or April when the snowpack begins to melt and inflows increase to a rate much greater than what is being released from Glen Canyon Dam. When this occurs the elevation of Lake Powell will begin to increase. It is currently projected that by late summer the elevation of Lake Powell will rebound to a peak elevation for water year 2011 of approximately 3639 feet above sea level. The peak elevation of Lake Powell for water year 2011 will depend largely upon the inflow volume that Lake Powell receives over the next 5-7 months.
Current Dam Operations
The release volume scheduled for February is 968 kaf. During the first 21 days of February daily releases will fluctuate for power production between an afternoon peak of approximately 19,700 cfs and an early morning low of approximately 15,000 cfs. On or about February 22, 2011, only 5 of the 8 generator units at Glen Canyon Dam will be available for electrical generation which will reduce the release capacity of Glen Canyon Dam Powerplant to approximately 16,000 cfs. In order to release the scheduled volume for February (968 kaf), releases during the period from February 22, 2011 to the end of February will be steady at approximately 16,000 cfs and this release regime will remain in place intil mid March when 2 additional units are projected to be returned to service. It is anticipated that the monthly release volume for March will likely be approximately 1020 kaf. Releases will be steady at approximately 16,000 cfs until Glen Canyon Unit 7 and 8 are returned to service on or about March 18, 2011. After March 18th, releases will resume daily fluctuations for power generation with daily peak releases each day of approximately 19,400 cfs. Early morning releases will be the lowest of the day and could be as low as 11,400 cfs.
In addition to daily operations that may or may not include daily fluctuation patterns, the instantaneous releases from Glen Canyon Dam can also fluctuate somewhat to provide approximately 40 megawatts of system regulation. These instantaneous releases adjustments maintain stable conditions within the electrical generation and transmission system and result in momentary release fluctuations within a range that is about 1100 cfs above or below the targeted release rate for a given hour of the day. These momentary fluctuations for regulation are very short lived and typically balance out over the hour. Spinning and non-spinning reserve generation can also occur at Glen Canyon Dam. When an unanticipated electrical outage event occur within the electrical transmission system, reserve generation at Glen Canyon Dam can be called upon up to a maximum of 98 megawatts (approximately 2,600 cfs of release) for a duration of up to 2 hours. Under normal circumstances, calls for reserve generation occur fairly infrequently and are for much less than the limit of 98 megawatts.