Western Colorado Area Office
Colorado River Storage Project
Aspinall Unit Operation Meeting
April 24, 2014
Blue Mesa Reservoir
Morrow Point Reservoir
The next operation meeting is scheduled for 1:00 p.m., Thursday, September 4th, 2014 at the Elk Creek Visitor Center at Blue Mesa Reservoir
This meeting was held at the Western Colorado Area Office in Grand Junction. Attendees are noted on the distribution list. Handouts are available for review and can be found in the menu at the bottom of the page.
The purpose of operation meetings-- usually 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 (www.usbr.gov/uc/water/crsp/studies/index.html) 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 2013-2014 operations; inflows to the reservoirs to date; and projected most probable, minimum, and maximum inflow forecasts for 2014; and potential operations for 2014.
A Record of Decision for the Aspinall Unit Operations Environmental Impact Statement was signed on May 3, 2012. The EIS modifies the operations of the Aspinall Unit to provide sufficient releases of water at times, quantities, and durations necessary to avoid jeopardy to endangered fish species and adverse modification of their designated critical habitat while maintaining and continuing to meet authorized purposes of the Aspinall Unit. 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 81,100 af, and dead storage is 111,200 af. Live capacity is the active plus inactive, which totals 829,500 af. Discussions during operation meetings use live capacity.
Runoff Forecast Discussion:
The initial soil moisture conditions entering the winter season were pretty favorable, with 70% of normal baseflow water and 130-150% of normal tension water. Snowpack is above average, much of which can be attributed to a huge jump in snowpack in February. We are currently in the active runoff period.
Current Conditions: Currently, the Gunnison River Basin has 92% of normal snow water conditions. The Gunnison Basin experienced a seasonal peak of 117% of normal, while the North Fork of the Gunnison Basin and the Uncompahgre Basin experienced peaks of 98% and 104% respectively.
Reservoir Status: The Gunnison Tunnel began diverting at the end of March. Blue Mesa Reservoir content is 460,000 AF as of April 23, 2014. The reservoir is 55% full. Taylor Park Reservoir is 65% full. Ridgway Reservoir is 85% full. Silverjack Reservoir is 78% full. Paonia is 4% full. Paonia is being kept at a low level to help sediment pass through the reservoir. There will be plenty of runoff to fill Paonia Reservoir.
Runoff Forecast: Forecasted unregulated inflow to Blue Mesa Reservoir is 126% of average, putting 2014 in the top 30% of years. The April – July unregulated inflow forecast is 850,000 AF, which is just above the boundary between the average wet and moderately wet categories.
Projected Operations: Assuming the forecast doesn’t change, the peak flow target for the Black Canyon water right is 6,427 cfs. This will probably require a 7,400 – 7,600 cfs release. Releases of this magnitude will require a spill at Crystal. For the first time since the finalization of the ROD, Reclamation will have to meet Peak Flow and Duration Day Targets. A bankfull flow of 14,350 cfs will need to be maintained for 10 days. A half-bankfull flow of 8,070 will need to be maintained for 40 days. It is likely that releases from Aspinall to meet the ROD targets will be greater than what would be required for the Black Canyon water right alone.
To help determine what actions Reclamation will have to take to reach and maintain these peak flows, tributaries to the Gunnison River need to be examined. As flows from the Cimmaron River go up, releases from Morrow Point will need to be adjusted. Up to 1,000 cfs can enter Crystal Reservoir from the Cimmaron River. The timing of Silverjack Reservoir filling and spilling will also be important. Silverjack has more storage than usual for this time of year, and it could fill by the 2nd week of May. The North Fork of the Gunnison River at Somerset has a forecasted peak of 3,200 cfs, with a runoff volume forecast of 300,000 AF. All these tributaries will contribute water to meeting the peak flow, however flows don’t typically stay high for 40 days.
A comment was brought up that the peak flows and duration day targets are based on Blue Mesa inflow, and they do not take into account the rest of the Basin. While Blue Mesa is in a moderately wet year, the rest of the Gunnison Basin is not. Having to use spillways to make up for the lack of water in the rest of the basin concerns some people.
There is the potential to adjust the peak flows and durations based on the May 15 forecast.
2014 Weather Outlook:
Extended Operations for CRSP Reservoirs:
A presentation was made by Aldis Strautins with the National Weather Service.
ENSO Models show us going to an El Nino pattern. We’ve actually tipped into the lower end of neutral. Historically, neutral years typically go to another neutral year or into El Nino. The following is forecasted:
Equal chances above/below average
Drought Monitor: Texas and California have areas in the highest drought category. The drought in Colorado is getting better in the west and north areas of the state, but is creeping into the South.
Sonar Mapping at Crystal Reservoir:
Presentation by John McClow (Upper Colorado River Commission) and Eric Kuhn (Colorado River District)
2012 and 2013 were the worst 2 consecutive years on record for moisture in the Colorado River Basin. What would have happened if there were 2 additional similar years?
Lake Powell would drop below the minimum power pool in 2015. This would impact hydropower, which pays for CERFP and CRSP projects. It also wouldn’t be able to release the full capacity of the bypass, so we wouldn’t be able to meet the Colorado River Compact.
There has been some contingency planning, and Aspinall is part of the plan. With no action, Lake Powell would be below the minimum power level 1/5 of the time. With basin demand management and re-operation plans, Lake Powell would be below the minimum power level only ~3% of the time. It is expected MOAs will be established for basin demand management and re-operation plans.
Sonor mapping of Crystal’s spilling basin took place on March 17th. The river was down to 300 cfs. This was coordinated with CPW, which was pit tagging fish to monitor the effectiveness of the electric barrier at the Gunnison Tunnel. The aerators at the powerplant were off for 4 hours on Monday. Pit tagging was done on Tuesday, with nothing unusual to report. On Friday, Gas Bubble Trauma showed up. We have operated at 300 cfs numerous times, however we have not been at that level without the turbines. We don’t know what the cause of the GBT was. If we ever get down to that level with similar conditions again, testing can be done to see if the cause of the nitrogen supersaturation can be determined.
Special Flow Requests:
No special flow requests were indicated.
Fish & Wildlife Service - If projected operations at bankfull and half bankfull stage come to fruition, the FWS wants to go out in the field with hydrophones to test when the sediment starts to move. This will not be an official publication, they just want to test the method and go back and see if their recommendations for operations hold up.
Power Office - There are no issues with their equipment or their ability to deliver water. They will monitor rocks in the Morrow Point stilling basin, but they are good to go to use the spillway.
Bureau of Land Management - Fishing in the Gunnison Gorge is a million dollar industry, with most fishing occurring in June. Looking at the proposed operation of the Aspinall Unit, they believe that commercial guides will be refunding trips and fishermen will not be happy.
Tri-County -The powerplant is online. The reservoir is a little high for the amount of snowpack still above the basin. They will probably bump up releases, coordinating with UVWUA. They will use the water to exercise the plant. If issues arise, they can replace/repair it under warranty. They expect the Uncompahgre River to have higher than normal flows for this year.
Colorado River Water Conservation District -Reminder about water planning at the state level, and there are monthly meeting with the Round Table. See www.crwcd.org
USGS -The have received a small increase in funding to infrastructure on NSIP program gauges. They expect to perform some maintenance work on some gauges.
Uncompahgre Valley Water Users Association - The tunnel is running ~600 cfs. They will maintain this level for a bit and use some water out of Ridgway.
Western Area Power Administration - With the state of Glen Canyon Dam, purchase price is going up. Aspinall Operations this spring could also drive up winter prices. They’ve already had to spend $46 million purchasing power only 6 months into the year. Also, bypassing the Morrow Point powerplant will impact the spillway, which Western is responsible for maintaining and repairing. Morrow Point power won’t be able to peak while there is spilling occurring at Crystal.
The next operations meeting is scheduled for 1:00 p.m., Thursday, September 4th, 2014 at the Elk Creek Visitor Center at Blue Mesa Reservoir
Meeting Minutes (Portable Document Format (PDF)): View these minutes as mailed (includes distribution/attendee list). Meeting handouts listed separately
see archive April 2014
Email comments/inquires to: WestColoAreaOffice@usbr.gov