Western Colorado Area Office

Participation

This meeting was held in Reclamation's Grand Junction Office. Attendees are noted on the distribution list. Handouts are available for review at http://www.usbr.gov/uc/wcao/water/rsvrs/mtgs/amcurrnt.html

Purpose of Meeting

The purpose of operation meetings-- held in January, April, and August-- is to gather input for determining upcoming operations for Blue Mesa, Morrow Point, and Crystal Reservoirs. This input is used in Reclamation=s development of specific operations for the Aspinall Unit and for the overall 24-month study for operation of Reclamation projects in the Upper Colorado River Basin, which include plans for Glen Canyon, Flaming Gorge, and Navajo Units, as well as the Aspinall Unit. Operation of the Aspinall Unit considers projected inflows to its reservoirs, hydropower and flood control needs, existing water rights, minimum instream flows, target elevations for reservoirs, flow needs for endangered fish and other resources, recreation, and other factors. In addition, the meetings are used to coordinate activities and exchange information among agencies, water users, and other interested parties concerning the Gunnison River.

Handouts provided included data on 2007-2008 operations; projected inflows to the reservoirs for 2008; and potential operation plans under probable maximum, most probable, and probable minimum runoff forecasts for 2008.

Activities related to long-term operation planning were also discussed at the meeting. Field studies leading to flow recommendations (Fish and Wildlife Service Flow Recommendations) to help recover downstream endangered fish and studies to quantify a Federal reserved water right have been completed for the Black Canyon of the Gunnison National Park.

The Fish and Wildlife Service flow recommendations for endangered fish have been completed and published, and an Aspinall Operations EIS has been initiated to evaluate alternative operations to help meet these recommendations. These operation meetings will be used more in the future to discuss proposals for long-term operation plans to address these and related resource management issues.

Forecasts

The Colorado Basin River Forecast Center gave a presentation on how runoff forecasts are produced (see www.cbrfc.noaa.gov). Presentation can be viewed at http://www.usbr.gov/uc/wcao/water/rsvrs/mtgs/amcurrnt.html. Forecasts are based on snow/water/reservoir conditions, weather patterns, and comparisons with historical data.

Operations

General: Blue Mesa Reservoir capacities are described in meetings as follows: The reservoir holds 940,700 acre-feet. Active capacity is 748,400, inactive capacity is 81,100, and dead storage is 111,200. Live capacity is the active plus inactive, which totals 829,500. Discussions during operation meetings use live capacity.

January-April 2008 Operations:

• The December 31 icing target for Blue Mesa was met. Unit releases were around 1,200 cfs on January 1 and were increased to around 1,800 cfs in January and February in response to the increasing snowpack to avoid the need to bypass power plants later in the year.
• In March Reclamation conducted sonar and dive inspections of the Crystal Dam stilling basin. This required ceasing releases for up to 3 hours to conduct the work. Inspections occurred on March 6 and March 18 and 19. Water was maintained downstream by regulating releases from the pool upstream of the Gunnison Tunnel Diversion Dam. Releases were ramped during the inspections to protect the fishery and ramping rates were adjusted based on observations during the initial inspection. Reclamation will give a full report on the inspection at the August operations meeting, but in summary the inspections were very successful and the stilling basin is in good condition. The CDOW reported that some 2007 year class fish were stranded and some brown trout redds dewatered under the low flow conditions.
• In late March and into April releases were increased and bypasses at Crystal began. Releases on April 24 were approximately 3,600 cfs, including a 1,500 cfs bypass.

2008 Operations:

• Early winter snowfall was lower than normal; however, late December and early January storms increased the snow pack significantly. The January 1 forecasted inflow to Blue Mesa was 780,000 af or 108 percent of average. By January 15, this number increased to 815,000 af. On April 1 the inflow was forecasted at 1,060,000 af or 146 percent of average. Based on these values, the year is categorized as "moderately wet", but is very close to a "wet" year. For comparison purposes inflow to Blue Mesa in recent wetter years was:
• 1984-199%
• 1986-137%
• 1995-173%
• 1997-147%
• Under most probable conditions, Crystal will be operated at full power plant capacity from April into September, and Blue Mesa would be expected to fill under min, most probable, and max forecast conditions. Flows in the Black Canyon and Gunnison Gorge should remain above 3,000 cfs well into July with flows in the 1,000-1,500 cfs range in late summer and fall.
• Under most probable conditions, a spill at Crystal is likely to occur. The timing of the spill is dependent on runoff timing and whether a decision is made to "force" a spill earlier than would occur naturally. Past runoff patterns were displayed on graphs showing that in addition to inflow quantity, weather patterns can greatly influence timing and magnitude of streamflows. If a spill is not "forced" the spill would likely occur in late June. During a spill, flows could increase to 4,000-7,000 cfs in the Black Canyon. It was pointed out that forecasts can still change and weather conditions over the next 2 months can significantly affect projections. This year flow levels in the Delta area are a concern. Preliminary forecasts for the North Fork near Somerset show a most probable peak the third week in May at around 5,000 cfs (mean daily). This of course can be affected significantly by weather patterns. A peak at Delta was projected around the same timeframe with a peak flow of 7,200 cfs + flows being released from the Aspinall Unit. In other words, if the Aspinall Unit was releasing 5,000 cfs into the Black Canyon at that time, peaks at Delta would be around 12,200 cfs.
• Reclamation stated that the operational priority this spring will be flood control.
• Input was requested from those in attendance concerning 2008 operations:
• Several representatives from Trout Unlimited suggested forcing a spill prior to June to better protect rainbow trout recruitment and to reduce the chances or magnitude of a June spill which can be detrimental to rainbow trout hatched this year. High water is needed to move sediment from the river and protective ramping rates are recommended to reduce stranding of young fish.
• The city/county of Delta is concerned with flood damage from peak flows; Delta and Reclamation will meet later to discuss planning and communications.
• The National Park Service would like to see a peak of 10,000 cfs in the Black Canyon, subject to Delta flooding concerns. The Fish and Wildlife Service would like to see flows at Whitewater around 14,000 cfs for 15-25 days, subject to Delta flooding concerns.
• The Bureau of Land Management would like at least 4 days prior notification of significant flow changes if possible to notify river users, particularly commercial guides that have clients travelling to the area. An early peak would probably be better for recreation than a late June peak.
• CREDA requested that power impacts be minimized.
• The Colorado Division of Wildlife indicated that rainbows have begun spawning which can continue till mid-May, so a peak after May 15 would be preferable. If a peak could occur between May 15 and June 1 it would be best because this would protect the spawning and would provide better conditions for survival of newly hatched rainbow trout. This timing would also benefit downstream native fish habitat. Peaks above 6,000 cfs would be excessive to support the sport fishery. Ramping rates, particularly when reducing flows, are crucial and if spills occur in June, ramping rates become critical for protection of newly hatched rainbow trout. Rates of 500 cfs per day (in several steps during the day) are suggested when ramping down from high peaks; rates of 250 cfs are suggested when river flows fall below 2,500 cfs.
• The CDOW requested flows in the 600-900 cfs range October 7-10 for the annual inventory in the Gunnison Gorge. This year's inventory is important to determine effects of low flows during the Crystal inspection and of higher spring flows.
• Other Reservoirs:
• Crawford, Fruitgrowers, Paonia, Silver Jack, Taylor Park and Ridgway are expected to fill this year under most probable conditions.