Aspinall Unit operations meeting recap: Forecasted April-July inflow to Blue Mesa is 370,000 acre-feet #coriver


From email from Reclamation (Dan Crabtree):

Participation: This meeting was held at the Holiday Inn Express in Montrose. Attendees are noted on the distribution list located at the end of these notes. Handouts and presentations are available for review at:

Purpose of Meeting: The purpose of operation meetings which are held in January, April, and August is to gather input for determining upcoming operations of the Aspinall Unit (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 includes plans for Glen Canyon, Flaming Gorge, and Navajo Units, as well as the Aspinall Unit. Operation of the Aspinall Unit considers forecasted inflows to the reservoirs, hydropower and flood control needs, existing water rights, minimum instream flows, target elevations for reservoirs; flow needs and flow recommendations 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 2012 operations; inflows to the reservoirs for 2012; and projected most probable, minimum, and maximum inflow forecasts for 2013; and potential operations for 2013.

The Fish and Wildlife Service flow recommendations for endangered fish were completed in 2003 and a final Aspinall Operations EIS and Record of Decision have been completed. Therefore operations to meet the flow recommendations have begun. In addition, the water right for the Black Canyon of the Gunnison National Park has been quantified and adjudicated. These operation meetings are used to discuss proposals for long-term operation plans to address these and related resource management issues.


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

Gunnison Basin Reservoirs: In 2012, Paonia and Silver Jack were the only Reclamation reservoirs to fill because of the limited runoff; and similar conditions are predicted to occur in 2013. Presently Taylor Park is 53% full; Ridgway 66%; Paonia 7%; and Silver Jack 19%. Inflow forecasts for 2013 are 63% of average to Ridgway; 60-65% to Taylor Park and 65% in the North Fork basin.

2012 Operations: The actual April through July inflow to Blue Mesa Reservoir was 206,000 af, the third lowest since 1937. The years 1977 and 2002 were lower. The April-July runoff at the Whitewater gage near Grand Junction was only 18 percent of average. Maximum content of Blue Mesa in 2012 was 543,000 af in April. Based on the May 1, 2012 inflow forecast to Blue Mesa, the Black Canyon National Park water right called for a 1-day peak of 814 cfs, which was met by an 845 cfs peak at the end of June. Flow Recommendations for endangered fish called for a 900 cfs peak in 2012 at Whitewater and this corresponded to the 900 cfs baseflow target for June and July which was met.

Black Canyon flows from August-September, 2012 were in the 600 cfs range and lowered to 320 cfs in October and remained there for the rest of the calendar year.

Flows at Whitewater Gage held up well through the fall eventually dropping to around 750 cfs in late December.

2013 Operations: Precipitation in the Gunnison Basin in October and November, 2012 was well below 50% of normal; December precipitation was near normal.

As of January 23rd, snowpack in the Gunnison Basin is only 62 % of the long-term average. (We would need 138% of average for the next 5 months to reach an average year). The inflow forecast to Blue Mesa is now 55% of the long-term average.

Blue Mesa content is now 327,000 af and has gained only 2,000 af through the winter.

As of January 15th, the forecasted April-July inflow to Blue Mesa is 370,000 af which is considered a Dry Year category and would be expected to be exceeded in 92 % of years.

If this inflow forecast holds true, it would represent the 5th lowest inflow since Blue Mesa was constructed (1977, 1981, 2002, and 2012 were lower).

Black Canyon National Park peak flow will be based on May 1 forecast; if the present forecast is maintained the peak would be 1016 cfs. However, a drought provision in the water right (based on the previous dry year and low Blue Mesa content) reduces this peak to 768 cfs.

Flow Recommendations call for a 900 cfs peak at Whitewater in a Dry Year based on the present forecasted inflow. This again, is equal to the baseflow target of 900 cfs for June and July.

Under most probable conditions, Blue Mesa is expected to reach 7476 feet in elevation (480,000 af content) which is 43 feet short of filling.

Average monthly Black Canyon flows during January through April are expected to be around 300 cfs and then increase to 500-650 cfs in the spring and summer.

It should be noted that snowpack conditions can change significantly after January and projected operations should be considered preliminary at this time.

Weather Forecasts: The National Weather Service projected some precipitation in the short-term but below average in the 8-14 day period. Last fall El Nino conditions were projected but did not materialize. Conditions are now near neutral and historically such conditions have resulted in a wide range of precipitation conditions; however, below average precipitation for the remainder of the winter is possible.

Above average temperature conditions are projected for the basin for the remainder of the winter (however, valley inversions may make you think otherwise).

Drought conditions in the Gunnison Basin are expected to persist.

Special Flow Requests: None.


State Engineer: In 2012 the Uncompahgre River was under call upstream from the M&D Canal beginning May 2. The Gunnison River gage at Gunnison reached record low flows. The North Fork basin and Grand Mesa water conditions were very low and carryover in private reservoirs is very low.

CRWCD: Discussing possible drought response with some of the large senior water right holders. State of the Gunnison River meetings will be held again this year: June 3 in Montrose and May 13 at Colorado Mesa University.

Upper Gunnison District: Lake San Cristobal work has been completed which increases available storage by 950 af.

National Park Service: Despite projected low reservoir levels, should still be good recreation opportunities at Blue Mesa.

Trout Unlimited: Relief Ditch Diversion restoration work is 35% complete and should be done by end of March. Will provide safer boat passage and improved diversion operations.

Delta County: Because of 2012 and 2013 dry conditions, very concerned with fire conditions this year. Noted that Larimer County was under Red Flag condition today.

Colorado Parks and Wildlife: Dan Kowalski has accepted a research position with CPW and his replacement has been selected.

Power Office: Normal maintenance of Aspinall dams and powerplants underway. No special projects.

UVWUA: South Canal hydropower project is under construction and some power may be produced this summer. Fish deterrent at the Gunnison Tunnel entrance has been completed and will be operated in 2013.

Western: Generation limited to 6 hours per day at Morrow Point and Blue Mesa. Crystal is generating using the 300 cfs release. Anticipates purchasing lots of energy this year due to dry conditions; prices are not too high this year. Had a high flow event at Glen Canyon; the high releases will be compensated with lower releases. Requested that National Park and endangered fish peaks be coordinated into one peak operation.

FWS: In January, the FWS proposed the Gunnison Sage Grouse as endangered under the Endangered Species Act. Comments on Federal Register notice are due March 12. Holding public meetings.

Tri-County: Ridgway is 15,000 af lower than January average. Releasing 30 cfs to preserve storage and will remain at 30 cfs until Uncompahgre Project needs water. Hydropower project is under construction and may produce some power by end of year.

BLM: 2012 was fairly slow year in the Gunnison Gorge…low flows make rafting very technical. Noted increase in fishing and recreation downstream from the North Fork confluence.

USGS: Gunnison River at Gunnison will now record water temperature.

Snow and Avalanche Center: One dust event last November 9th. Snowpack very low on study sites.

Next Meeting: April 25th at Reclamation’s Office in Grand Junction.

More Aspinall Unit coverage here.

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