From email from Reclamation (Eric Knight):
May 21, 2025
The May 1st forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 460,000 acre-feet. This is 72% of the 30 year average. Snowpack in the Upper Gunnison Basin peaked at 93% of normal. Blue Mesa Reservoir current content is 527,000 acre-feet which is 64% of full. Current elevation is 7483.4 ft. Maximum content at Blue Mesa Reservoir is 828,00 acre-feet at an elevation of 7519.4 ft.
Based on the May forecasts, the Black Canyon Water Right and Aspinall Unit ROD peak flow targets are listed below:
Black Canyon Water Right
The peak flow target is equal to 2,360 cfs for a duration of 24 hours.
The shoulder flow target is 300 cfs, for the period between May 1 and July 25.
Aspinall Unit Operations ROD
The year type is currently classified as Moderately Dry.
The peak flow target is 4,585 cfs for a duration of 1 day (based on a May 15 forecast of 430 Kaf)
There are no half bankfull duration or peak duration targets.
Pursuant to the Aspinall Unit Operations ROD, releases from the Aspinall Unit will be made in an attempt to match the peak flow of the North Fork of the Gunnison River to maximize the potential of meeting the desired peak at the Whitewater gage, while simultaneously meeting the Black Canyon Water Right peak flow amount. The latest forecast for flows on the North Fork of the Gunnison River shows a period of high and near peak flows beginning on May 29th.
Therefore ramp up for the spring peak operation will begin on Saturday, May 24th, with the intent of timing releases with this potential higher flow period on the North Fork of the Gunnison River. Releases from Crystal Dam will be ramped up according to the guidelines specified in the EIS, with 2 release changes per day, until Crystal begins to spill. The release schedule for Crystal Dam is:
Crystal Dam will be at full powerplant and bypass release on May 28th and Crystal Reservoir will likely begin spilling by the next day. The peak release from Crystal Dam should be reached on May 29th and the peak flow on the Gunnison River at Whitewater should be reached on May 30th.
The current projection for spring peak operations shows flows in the Gunnison River through the Black Canyon peaking around 3700 cfs in order to achieve the desired peak flow at Whitewater. Actual flows will be dependent on the downstream contribution of the North Fork of the Gunnison River and other tributaries. Lower tributary flows could lead to higher releases from the Aspinall Unit and vice versa. Once the peak target has been reached, details of the ramp down operation will be released.
