Colorado River Storage Project
Fontenelle Working Group
April 23, 2014
This meeting was held at the Seedskadee Wildlife Refuge in Green River, Wyoming. See below for a list of participants.
The purpose of working group meetings (held in April, and August) is to inform the public and other interested parties of Reclamation's current and future operational plans and to gather information from the public regarding specific resources associated with Fontenelle Reservoir. In addition, the meetings are used to coordinate activities and exchange information among agencies, water users, and other interested parties concerning the Green River.
Edward Vidmar (USBR) called the meeting to order shortly after 10:00 a.m. with 17 present (see signup sheet for attendance). Presentations were given in the following order: Ashley Nielson, the National Weather Service Colorado River Forecast Center (CBRFC) followed by Heather Patno, Bureau of Reclamation. Before starting, all present introduced themselves and their affiliations.
Ashley Nielson with the Colorado River Basin Forecast Center (CBRFC) in Salt Lake City provided a review of fall and winter weather patterns in addition to characterizing spring snowpack conditions. She then described the April-July water supply forecast for the Green River Basin above Fontenelle, and briefly discussed long term weather forecasts.
Weather Review (Fall + Winter)
The Green River Basin above Fontenelle received above average precipitation in most fall and winter months, including September (220% of average), October (145% of average), December (130% of average), February (220% of average), and March (120% of average). During February, in particular, very moist and mild air was transported into the Western United States. This “atmospheric river” produced significant precipitation in the Green River Basin of Wyoming and in the northern Bear River Basin. This resulted in above or much above average precipitation in the Yampa, Colorado Headwaters, and Upper Gunnison. Several sites reported 300-400% of average monthly precipitation. In many cases, this amounted to the 2nd highest February precipitation for the period of record.
Snow conditions were consistent with the 30-year average through the end of January. However, above average precipitation in February resulted in much above average snow water equivalent (SWE) for the season. The Snotel group representing the Green River Basin above Fontenelle peaked at 24.4 inches, or 162% of the 30-year (1981-2010) median seasonal peak (15.1 inches), during the first week of April (04/05/14).
Water Supply Volume Forecasts
As of February 1st, the CBRFC’s official forecast of seasonal water supply volume was consistent with the 30-year median. However, the forecast increased substantially in March, due to abundant precipitation received in February. The April 1st most probable (50% exceedance probability) water supply volume forecast for the Green River at Fontenelle (GBRW4) amounts to 1,210 KAF, or 167% of average. However, it was noted that the CBRFC’s April and May forecasts tend to underestimate seasonal flow volumes in “wet” years.
Long Term Weather
While current weather patterns reflect neutral ENSO conditions, several models point to the potential development of El Nino conditions in fall 2014. El Nino conditions generally produce cooler and wetter conditions in the southern U.S., and drier and warmer conditions in the northern U.S. However, because the Green River Basin above Fontenelle is located between these distinct areas, there is no strong correlation between weather patterns in the region and El Nino conditions.
The 90-day outlook for May, June and July indicates equal chances for above and below average temperatures and a chance for above average precipitation in a portion of the basin.
Hydrology and Operations Presentation - Heather Patno
Heather Patno presented the current conditions at Fontenelle Reservoir and described anticipated WY 2014 operations. As of April 22, 2014, Fontenelle Reservoir was 34% full, which correlates to 36.2 ft below maximum reservoir elevation (6506.0 ft). This is typical for the time of year, given the above average runoff forecast. The current release is 1,420 cfs, and the 5-day average inflow is 1,600 cfs.
The operational plan, based on the April forecast of 1,210,000 AF, is to maintain a release of 1,420 cfs through the end of April. Releases would be increased to 4,000 cfs in May, and then increased to 8,000 cfs in June. These flows are significantly higher than the 2013 peak release of 800 cfs. Releases would be reduced to 3,000 cfs in July before returning to an estimated base flow of 1,250 cfs in August or September, where they will remain through fall and winter. Given the April inflow forecast and anticipated operations, Fontenelle Reservoir is expected to peak at full capacity (pool elevation 6506.0 ft) in September 2014.
A request was made to adjust releases for either a) a faster ramping rate or b) larger flow volumes in order to flush sediment. Also known as “dry year flushing,” this practice benefits habitat, as shown by studies in the Platte River. It was noted that Big Sandy may not fill, and its contributions to the river via spill will likely be limited. Fontenelle operators agreed to maintain the 20% ramp rate from 1,400-4,000 cfs, and to increase to a 30% ramp rate for releases from 4,000-8,000 cfs. Operators will provide 4-7 days of notice when releases are to be increased.
A few questions were asked regarding Flaming Gorge operations. Current releases amount to 830 cfs. In accordance with the Endangered Fish Recovery Program, 2014 will be an experimentation year, such that peak releases will be timed in conjunction with the detection of razorback sucker larvae. Per the final April forecast, 2014 is hydrologically classified as a “moderately wet” year, though this is subject to change as operations will be based on the May 1st official forecast. The LTSP requires a bypass of 8,600 cfs for 14 days under these conditions. The larval trigger will likely follow the observed peak in the Yampa River, which is forecast at 15,000 cfs. Storage in Flaming Gorge is expected to peak at elevation 6032 ft.
There was some discussion regarding the “Out of the Box” program, in which Colorado River Basin stakeholders are discussing strategies to improve conditions in the Lower Basin. The State Engineer will be attending the Green River Basin Advisory Group’s public meeting at 6pm on Tuesday, May 20th at the Joint Powers Board Meeting Room in Green River, WY to discuss these issues.
The next meeting date was set for 10:00am on Wednesday, August 20, 2014, at the Joint Powers Water Board in Green River, WY.
Fontenelle Working Group Meeting Minutes:
|Heather Patno||Bureau of Reclamation, Salt Lake City|
|Steve Hulet||Bureau of Reclamation, Flaming Gorge Dam|
|Kirk Jensen||Bureau of Reclamation, Fontnelle Dam|
|Edward Vidmar||Bureau of Reclamation, Provo|
|Lee Traynham||Bureau of Reclamation, Provo|
|Peter Crookston||Bureau of Reclamation, Provo|
|Ashley Nielson||Colorado Basin River Forecast Center|
|Doug Stewart||City of Green River|
|Erik Roosa||City of Green River|
|Ben Bracken||Upper Colorado River Commission (Wyom Rep)|
|Bryan Seppie||Joint Powers Water Board|
|Mike Meyer||Pacificorp, Jim Bridger Power Plant|
|Robert Keith||Wyoming Game & Fish|
|Tom Koerner||Seedskadee NWR|
|Howard Hart||Trout Unlimited|
|Judy Roderick||Sweetwater County Emergency Mgt|
|David Johnson||Sweetwater County Emergency Mgt|
Email comments/inquires to: ResourceMgr@usbr.gov