Last Updated: May 7, 2020
Aspinall Unit Reservoirs – As of May 5, 2020 releases from Crystal Dam are approximately 1,450 cfs. Gunnison Tunnel diversions for irrigation season are increasing each week and as of today UVWUA is diverting 1,050 cfs through the Gunnison Tunnel. The capacity of the Gunnison Tunnel is approximately 1,150 cfs. Flows in the Black Canyon are about 420 cfs. Reclamation is currently (May 7, 2020) operating day-to-day watching the North Fork of the Gunnison River looking for the most prominent peak flow in order to trigger the spring peak release from Aspinall for this year.
The most recent forecast (May) for unregulated inflow during the water supply period (April through July) is projecting Blue Mesa will receive 450,000 af. Based on this forecast, the spring peak flow of the Gunnison River in the Whitewater Reach Reclamation plans to target a peak flow of approximately 5,400 cfs for 1 day. Additionally, Reclamation plans to target a peak flow of the Gunnison River within the Black Canyon of 2,210 cfs for 1 day. Reclamation will gradually increase releases over multiple days to achieve these peak targets and then will gradually decrease releases after the targets have been achieved. The peak release will require elevated releases from Aspinall for approximately 2 weeks.
Blue Mesa is not projected to fill this year based on the most recent inflow forecast. On May 5, 2020, the elevation of Blue Mesa was 7481.83 feet above sea level corresponding to a live storage of 519,400 af (63 percent of capacity). The elevation of Blue Mesa is currently rising each day as inflows are exceeding releases. By late July, based on current projections, the elevation of Blue Mesa is projected to reach about 7502 feet above sea level which corresponds to a live storage level of 678,000 af (82 percent of full capacity).
The unregulated inflow volume in April to Blue Mesa was 50,000 af (65 percent of average). Unregulated Inflow volumes forecasted for Blue Mesa for the next three months (May, June and July) are projected to be: 175,000 af (79 percent of average), 167,000 af (64 percent of average) and 58,000 af (50 percent of average), respectively. The May 24-Month Study is reflective of these new forecasts. The April through July forecasted most probable unregulated inflow volume to Blue Mesa is 450,000 af (67 percent of average). The 2020 water year forecasted unregulated inflow volume is 692,500 af (73 percent of average).
The Aspinall Unit Working Group is an open public forum for information exchange between Reclamation and the stakeholders of the Aspinall Unit. The public is encouraged to attend and comments on the operations and plans presented by Reclamation at these meetings. Meeting notes from past working Group meetings are posted on the Working Group webpage. For more information on this group and these meetings please contact Erik Knight in the Grand Junction Area Office at (970) 248-0629.The next meeting of the Aspinall Unit Working Group was to be held in August of 2020. The exact date and time have not yet been scheduled. The meeting will likely be held at the National Park Service visitor center at Blue Mesa Reservoir. More details will be shared as they become available.