Colorado River Storage Project
Flaming Gorge Working Group
August 21, 2014
This meeting was held Thursday, August 21st, 2014, at the Utah Department of Natural Resources building in Vernal, Utah. Attendees are listed below.
The purpose of these 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 Flaming Gorge Reservoir and the river corridor below it. In addition, the meetings are used to coordinate activities and exchange information among agencies, water users, and other interested parties concerning the Green River.
Heather Patno (USBR) called the meeting to order at 11:00 a.m. with 16 present in person and several participating via the online conference Webinar (see signup sheet for attendance). Presentations were given in the following order: Ashley Nielson of the National Weather Service Colorado River Forecast Center (CBRFC); Heather Patno, Bureau of Reclamation and Tom Chart, US Fish and Wildlife Service (USFWS). 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 WY 2014 weather patterns in addition to characterizing spring snow pack conditions. She then described spring and summer streamflows and discussed the April-July runoff forecast performance for the Green River Basin above Flaming Gorge. She briefly discussed long term projections and guidance related to WY 2015.
The Upper Green River Basin 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 (115% of average). Similarly, the Yampa River Basin received above average precipitation in September (200% of average), October (153% of average), December (108% of average), January (125% of average), and March (110% of average).
During February, 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 in the Upper Green reported 300-400% of average monthly precipitation. In many cases, this amounted to the 2nd highest February precipitation for the period of record. In the Yampa Basin, several high elevation sites reported ~150% of average monthly precipitation.
Late spring and summer months were somewhat drier, with only July (110% of average) and August being above average on the Green, and only May (112%) and August above average on the Yampa. Seasonal precipitation through May (i.e. Oct 2013 – May 2014) was at or above average in both the Upper Green (90-130%) and in the Yampa (100-110%) basins.
In general, spring was characterized by near normal temperatures with occasional interruptions of a few days with above or below average temperatures. Snowmelt was initiated by stretch of above average temperatures in mid-April, and runoff peaked during a warm period at the end of May. However, temperatures returned to normal in early June, and spring runoff was interrupted by a cold storm system that arrived in mid-June.
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 Upper Green River Basin peaked at 21.1 inches, or 149% of the 30-year (1981-2010) median seasonal peak (14.2 inches), during the first week of April (04/07/14). The Snotel group representing the Yampa River Basin above Deerlodge peaked at 28.9 inches, or 130% of the 30-year (1981-2010) median seasonal peak (22.3 inches), in early April (04/09/14). Snowmelt was largely complete in both basins by July 1st.
Streamflows in both the Green and Yampa Rivers peaked during the first week of June. The Green, Yampa, and Colorado Rivers all peaked at roughly the same time, which is unusual. Flows were above to well above average throughout the water supply period from April through July.
Water Supply Volume Forecasts Review
As of February 1st, the CBRFC’s official forecast of seasonal water supply volume for the Green River at Flaming Gorge 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 Flaming Gorge (GRNU1) was 1,400 KAF, or 143% of average. The May and June forecasts were identical at 1,320 KAF, or 135% of average. The observed WY 2014 runoff volume amounted to 1,160 KAF, or 118% of average.
Due to the limited impact of the wet February weather pattern in the Yampa River Basin, the water supply forecast changed relatively little throughout the season. The April 1st most probable (50% exceedance probability) water supply volume forecast for the Yampa River near Deerlodge (YDLC2) was 1,550 KAF, or 125% of average. The most probable forecast remained unchanged through June 1st. The observed WY 2014 runoff volume amounted to 1,414 KAF, or 114% of average.
It was noted that the CBRFC’s April and May forecasts tend to underestimate seasonal flow volumes in “wet” years, but this was not the case in WY 2014. This may have been due to inconsistent spring temperatures (i.e. a mix of warm and cool weather), which tend to result in inefficient runoff and lower streamflows.
The mid-April most probable (50% exceedance probability) peak flow forecast for the Yampa River near Deerlodge called for a peak flow of 16,500 cfs to occur in late May. The forecast was consistent with the observed peak of 16,500 cfs, which occurred on June 1st.
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. However, the probability of a strong El Nino developing is decreasing. El Nino conditions generally produce cooler and wetter conditions in the southern U.S., and dryer and warmer conditions in the northern U.S. However, because the Green River Basin above Flaming Gorge 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 August, September, and October indicates equal chances for above and below average temperatures and a 30-40% chance for above average precipitation in both the Upper Green River and Yampa River basins. As a result, above average inflows are forecasted for Flaming Gorge in August (118%), September (109%), and October (104%). Above average flows in the Yampa River at Deerlodge are forecasted for August (110%), while below average flows are anticipated in September (65%) and October (70%).
Heather Patno first provided an overview of the 2006 Record of Decision Operation Criteria and the 2014 Adaptive Management Operating Criteria, which dictate the operation of Flaming Gorge Reservoir. She then reviewed WY 2014 operations, discussed current reservoir conditions, and described anticipated operations for WY 2015.
ROD and LTSP Background
Flaming Gorge operations are dependent on conditions in three reaches, defined as follows: Reach 1 consists of the Green River from Flaming Gorge Dam to the Yampa River Confluence; Reach 2 covers the Green River from the Yampa River Confluence to the Duchesne River Confluence; and Reach 3 includes the Green River from the Duchesne River Confluence to the Colorado River Confluence.
The 2006 Record of Decision (ROD) defines the Flaming Gorge Reservoir operations planning process. The Flaming Gorge Technical Working Group (FGTWG) includes representatives from Reclamation, U.S. Fish and Wildlife Service, and Western Area Power Administration. The FGTWG considers Green and Yampa River hydrology as well as Upper Colorado River Endangered Fish Recovery Program Research Flow Requests in order to propose Green River flow and temperature objectives by mid-April. Spring flow and base flow requests are jointly determined by various stakeholders, including the State of Utah, Staty of Wyoming, National Park Service, U.S. Fish and Wildlife Service, Western Area Power Administration, and the general public, and are submitted for consideration by April 1st. The Flaming Gorge Working Group (FGWG) then considers basin hydrology, FGTWG’s proposed flow and temperature objectives, and the Spring and base flow request. Reclamation then makes its Spring and Summer operating decisions in mid-May.
The final (May) Flaming Gorge April-July water supply forecast was 1,320,000 AF (141% of average), which resulted in an “average wet” hydrologic classification and reservoir operations were determined accordingly. The observed April-July water supply volume was 1,159,000 AF (118% average), which corresponds to a 41% exceedance probability for the period of record (1963-2013). Both the forecast and observed inflow volume fall within the “average wet” hydrologic classification. Given forecasted inflows for the remainder of August and September, unregulated inflows for WY 2014 are projected at 112% of the annual average. This is significantly higher than the WY 2013 unregulated inflow volume, which amounted to 45% of the annual average.>/p>
The final (May) Yampa River basin forecast was 1,550,000 AF or (125% of average). The observed water supply volume for the Yampa River (Maybell + Lily) was 1,414,000 AF (114% of average). While the May forecast volume fell within the “moderately wet” hydrologic classification, the observed volume resulted in an “average wet” classification.
Spring Operations (Larval Trigger Study Plan)
In 2014, the U.S. Fish and Wildlife Service requested that base flow targets be augmented by as much as 40% in order to comply with the 2006 ROD and 2005 biological opinion (BO). In addition, the Upper Colorado River Endangered Fish Recovery Program requested releases to support the 2014 Larval Trigger Study Program (LTSP). The goal of the LTSP was to entrain larval razorback sucker in wetland areas by coordinating releases with a biological trigger (i.e. the presence of fish larvae) rather than a hydrologic trigger (i.e. Yampa River peaks), as was done in the past in accordance with the ROD. LTSP operations were discussed further by Tom Chart in a subsequent presentation. Reclamation committed to make releases necessary to meet the goals of the ROD and the LTSP by augmenting Yampa River flows with the minimum required Flaming Gorge releases, including bypass releases, if necessary. Given the “average wet” hydrologic classification, a peak flow target of 18,600 to 20,300 cfs in the Green River at Jensen, UT for a period of 1-14 days was established.
Baseflow releases of ~830 cfs were maintained until the last few days of May, when larval razorback sucker were observed. Releases were then increased to power plant capacity (4,600 cfs), which was maintained for three days. Bypass releases were initiated on June 6, and were maintained at full capacity (4,000 cfs) for 9 days. These operations resulted in a total LTSP release volume of 278,000 AF. Coordinated operations allowed the LTSP target to be met, as flows at Jensen exceeded 18,600 cfs for a total of 4 days, with a peak observed flow of 19,500 cfs. Flows exceeded 8,300 cfs for 44 days, and 24 days coincided with the presence of razorback sucker larvae.
It was noted that alternate operations would have been implemented under the ROD program. The ROD would have required a peak flow of at least 18,600 cfs to be maintained for 14 days in addition to a modified peak of 22,000 cfs. These operations would have resulted in 11 days at power plant capacity (4,600 cfs) and 6 days at bypass capacity (4,600 cfs + 4,000 cfs = 8,600 cfs). The total release volume associated with these operations would have been 293,000 AF, or 15,000 AF more than was released under the LTSP operations.
Current and Projected Hydrology and Operations
The 2014 peak reservoir elevation of 6028.6 ft which was below the targeted peak. The difference is primarily due to the difference in the forecasted (1,550 KAF) and observed (1,414 KAF) inflow volumes. As of August 19, 2014, Flaming Gorge Reservoir was 88% full, which corresponds to an elevation of 6028.45 ft, or 120.5 ft above minimum power elevation (5908.0 ft). This is a notable improvement over conditions last year at this time, when the reservoir was 76% full after receiving only 37% of its average inflow volume. Reservoir storages throughout the Upper Colorado River system are generally much higher than in 2013. The current release from Flaming Gorge is 2,000 cfs, while inflows are 1,470 cfs. The US Fish and Wildlife Service (USFWS) has requested that 2,400 cfs baseflow be maintained in the river through September for the benefit of the Colorado pikeminnow.
The WY 2015 Flaming Gorge unregulated inflow most probable forecast is for 1,330,000 AF (91% of average), with a range of 920,000 AF (63% of average) to 2,520,000 AF (173% of average). The most probable April-July release forecast is for 852,000 AF (87% of average), with a range of 495,000 AF (51% of average) to 1,805,000 AF (184% of average). These forecasts are consistent with the ensemble median, but are slightly below average. The forecasts currently have low skill, but will improve when revised in the fall when additional initial condition information is available.
Operational flexibility exists in Flaming Gorge releases and corresponding Green River base flows. From August through November, mean daily flow should be within 40% of the mean annual base flow. From December through February, mean daily flow should be within 25% of the mean annual base flow. The rate of change in mean daily flow from day to day should not exceed 3%. Fluctuation between maximum an dminimum daily flows should produce no more than a 0.1-m change in stage at the USGS stream gage near Jense, UT.
Western Area Power Administration (WAPA) has requested baseflows be maintained at 25% above average for the months of December, January, and February. Given the 25% augmentation requested by WAPA, Reach 1 base flows (downstream end at confluence of Green River and Yampa River) can range from 800 cfs to 2,750 cfs in an average year. Similarly, Reach 2 baseflows (as measured in the Green River at Jensen, UT) can range from 1,125 cfs to 3,000 cfs in an average year.
The most probable spring 2015 operations, based on the current 2015 forecast, include an average spring peak release at power plant capacity (4,600 cfs) to be maintained for two weeks, followed by a baseflow release of 1,300 cfs for the remainder of the year. The most probable peak reservoir elevation for WY 2015 is 6,027 feet in September 2015. This corresponds to the flood control target given the forecasted inflows.
Tom Chart (USFWS) discussed spring and summer activities related to the 2014 Larval Trigger Study Plan (LTSP). The LTSP was implemented as part of the Upper Colorado River Endangered Fish Recovery Program Spring Flow Request. The goal of the Recovery Program is to recover endangered fishes while water development proceeds in compliance with applicable Federal and State laws. It balances the Endangered Species Act (ESA) with the Law of the River, and provides ESA compliance for historic and new water depletion projects.
2014 LTSP Flow Proposal
The Recovery Program submitted its request to implement the Larval Trigger Study Plan in WY 2014 on March 21st. The Flaming Gorge Technical Working Group (FGTWG) met on March 20th and April 22nd to consider factors such as hydrology, the Recovery Program request, endangered fish status, Record of Decision (ROD) flow recommendations, and current science in order to develop a range of flow alternatives. Public input on the FGTWG flow proposal was collected during the Flaming Gorge Working Group (FGWG) April meeting.
In 2014, the goal of the LTSP was the entrainment of larval Razorback Sucker (RZB) in designated wetlands. In previous years (prior to 2012), program emphasis has been on levee elevation and timing of peak flows with the Yampa River, rather than on the timing of larval drift. In 2012, most wetlands dried up before juvenile fish could be returned to the river. In WY 2013, 700 RZB were salvaged from Stewart Lake.
The 2014 FGTWG recommendation was to “pursue moderately wet year flow objectives which would provide connection of river to moderately wet wetlands for 1-14 days or more during the period of larval drift as described in the Larval Trigger Study Plan.”
2014 LTSP Activities (razorback sucker)
The observed unregulated inflow into Flaming Gorge resulted in a hydrologic classification as “average wet,” rather than “moderate wet.” The targeted floodplains for an “average wet” hydrologic year and their minimum inundation thresholds are as follows: Escalante Ranch – 11,000 cfs, Stewart Lake – 4,000-8,000 cfs, Bonanza Bridge – 13,000 cfs, Stirrup – 11,000 cfs, and Above Brennan – 10,000 cfs.
The first capture of razorback sucker was reported on May 28th, at which time the Stewart Lake outlet gate was opened and Reclamation began to ramp up releases. The Stewart Lake inlet was opened on June 10th, and then subsequently closed on June 15th as Reclamation began to ramp down releases. Following initial detection, flows at Jensen exceeded 8,300 cfs for 25 days and exceeded 18,600 cfs for 4 days.
From July 21-24th, the UDWR captured 13 RBS in Stewart Lake. From August 4th-7th, UDWR captured 29 RBS in Stewart Lake. UDWR will drain Stewart Lake in September, at which point UDWR and USFWS will sample for juvenile RBS at each of the targeted inundation sites.
2014 Base Flow Request (Colorado pikeminnow)
A base flow request is typically prepared by the USFWS field office in Salt Lake City in cooperation with the Recovery Program. While Reclamation typically selects the flow target according to the ROD base flow range, the target can be augmented by as much as 40% through September 30th. The FGTWG recommended providing “adequate” base flows in order to maintain quality Colorado pikeminnow habitat and to disadvantage smallmouth bass. As a result, Reclamation selected a Reach 2 target of 2,400 cfs through September 30, 2014, which is consistent with the “average” hydrologic year maximum base flow without augmentation.
2014 Temperature Targets
Temperature targets were established by the 2006 ROD. Temperature targets for 2014 should be managed to be at least 18 degrees Celsius for 2-5 weeks in the Upper Lodore Canyon during the beginning of the base flow period. Water temperatures in the Green River should be managed to be no more than 5 degrees Celsius colder than those of the Yampa River at the confluence of the Green and Yampa Rivers from June through August 2014.
Dam releases are typically 13-16 degrees Celsius from June 15th to September 30th.
In past years, have LTSP operations resulted in a larger or smaller volume than would have been released under the ROD requirements? Past years haven’t been reviewed, but in 2014 a smaller volume was released under the LTSP.
Under the ROD, the peak release would have occurred earlier, when the Yampa reached 10,000 cfs. Is there any indication that earlier releases from Flaming Gorge and the associated cooler river temperature impacts might have resulted in earlier razorback sucker larva presence? It’s currently unclear what factors trigger the presence of razorback sucker.
Based on the August forecast, Lake Powell is in the upper elevation balancing tier, though this condition will be revisited in the fall. While releases were set at 7.48 MAF in 2014, they may be set at either 8.23 MAF or 9.0 MAF, depending on conditions, for 2015.
Given conditions at Lake Mead, is it possible that Lake Powell will make releases to supplement Lake Mead, and that Flaming Gorge and Fontenelle will be required to make additional releases as well? The Upper and Lower basins are discussing drought contingency plans, which include operating all Upper Basin facilities to maintain Powell above minimum power pool. In this case, Lake Powell elevations would be targeted, rather than Lake Mead. However, such changes to operations would require 6-12 months of discussion. The Lower Colorado is generally entitled to 75 MAF from the Colorado River over 10 years.
What has the impact of the LTSP been on trout species? The LTSP has increased spring peaking, which is beneficial for brown and rainbow trout due to the resulting scouring effect. However, it’s unclear if the habitat improvements can be primarily attributed to LTSP operations or to extreme events that occurred in 2011.
What are the socioeconomic impacts of the LTSP and are revenue losses being mitigated? Some outfitters report significant cancellations that coincide with the high river flows. However, the number of cancellations directly related to flow conditions that did not reschedule trips for later dates is unclear. Most would appreciate more advanced notice and improve communication as they continue to adapt to the transition from ROD to LTSP guidelines, which has resulted in a shift in the timing of peak releases and associated high river flows. The outfitters generally felt like there were several short-notice changes in 2014. They also recognize that there is a disconnect between receiving 3 days’ notice with respect to flow changes, while they typically book clients up to months in advance. Downstream irrigators would also appreciate more notice, but they generally benefit from peak reservoir releases being offset from the Yampa River peak.
Reclamation operators noted that bypass flows would have occurred under both the ROD and the LTSP operating guidelines. However, ROD operations allow for more noticed because peak releases are based on the Yampa River streamflow forecast, which is known in advance. Peak releases under the LTSP are based on the presence of fish larva and are less predictable. Operators encourage the LTSP biologists to provide as much notices as possible, but understand that razorback sucker are the first larva in the system and there are no earlier indicators.
In 2014, there were two spring ramp-ups and each was implemented differently. The first was initiated at 7pm at night and the river had stabilized by morning. The second ramp up was initiated on a Friday morning and continued over four hours. Recreational users have a strong preference for ramp-up to be initiated at night and early or mid-week (i.e. not on Fridays or over a weekend) in order to minimize impacts of high flows and associated debris. Reclamation operators noted that there are constraints on the timing of the ramp-ups. Power plant releases are controlled at Glen Canyon, which is staffed 24 hours a day, such that ramp-up to power plant capacity can occur at night. However, bypass releases are controlled through physical operations at the Flaming Gorge dam, which is staffed Monday through Thursday. While a late afternoon, early-week release is possible, night-time releases require changes to shift schedules as well as Union approval. In addition, bypass releases are typically ramped up very quickly to compensate for a rapid decline in Yampa flows. This is difficult to accomplish overnight. It was also noted that there is a lag of up to two days before changes made at the dam result in flow impacts at Jensen.
In general, the angling community, including outfitters and biologists, agree that bypass flows are a great benefit to the fishery.
Why was the 2011 young-of-year Colorado pikeminnow catch 0? Biologists believe that the spawn numbers were low that year, and that this was followed by very low survival into the fall. In general, razorback sucker benefit from high water years. Alternatively, Colorado pikeminnow benefit from a high water in the preceding year and average current year flows.
Does UDWR capture other fish, including predators, when light trapping razorback sucker? Yes, both native and non-native fish flock to wetland areas. Trappers set up mirrors to try and keep large fish out of the wetlands. They also note that it’s critical to drain the wetland areas each year to limit the number of predators in the inundation area and improve the chances of razorback sucker survival.
The next meeting of the Flaming Gorge Working Group was set for 11:00 am on Thursday, April 23rd, 2015 at the new Utah Department of Natural Resources building in Vernal, Utah, located at 318 North Vernal Avenue.
PLEASE NOTE: The Flaming Gorge Working Group has been moved to 11:00 am on Thursday, April 30, 2015, at the same location.
|Gawain Snow||Uintah Water Conservancy District|
|Boyd Kitchen||Utah State University Extension|
|Trina Hedrick||Utah Division Wildlife Resources|
|Ryan Mosley||Utah Division Wildlife Resources|
|Warren Blanchard||Daggett County|
|Charles Card||Trout Unlimited|
|Laura Belanger||Western Resource Advocates|
|Brian Raymond||Daggett County|
Flaming Gorge Working Group Meeting Minutes:
- April 24, 2014
- August 21, 2013
- April 24, 2013
- August 22, 2012
- April 18, 2012
- August 23, 2011
- April 26, 2011
- August 26, 2010
- April 27, 2010
- August 26, 2009
- April 15, 2009
- August 20, 2008
- April 16, 2008
- August 23, 2007
- April 19, 2007
- August 22, 2006
- April 13, 2006
- November 2, 2005
- October 28, 2005
- August 25, 2005
- April 20, 2005
- August 19, 2004
- April 15, 2004