Getting to Know the Flaming Gorge Dam

August 17, 2023

By: Luke Rogers

The Early Days

In 1825, the fur trapper William Ashley pushed off onto the upper Green River with a crew of seven men in “bull boats”: rudimentary craft built by stretching buffalo hide over lightweight willow frames. This technique of boat building, widely borrowed from Native Americans by Anglo fur traders, allowed the Ashley party to accomplish the first known descent of the Green from modern-day Wyoming into the Uintah Basin, near the present-day town of Vernal, Utah.

Along the way, the river transitioned from high sagebrush prairie into deep mountain canyons, where sheer cliffs of brilliant red rock towered hundreds of feet above the water. Explorer and surveyor John Wesley Powell later named this place Flaming Gorge, in recognition of the vibrant colors. Willows and sandy beaches lined the riverbank, and ponderosa pines clung to the walls where gentler slopes allowed them a foothold. In the words of one early river runner, “The canyons were short and rapid-free, filled with sunshine and songs of countless birds, and with the call of geese and ducks high overhead. Many deer and beaver could be seen along the tree-lined shores.”

Further downstream, Ashley’s party encountered serious whitewater, prompting the novice boaters to portage cautiously around on land. Ashley carved his name on a rock near one of the most severe rapids, and Ashley Falls became a right of passage for future generations of river runners. The famous Kolb Brothers, for example, waited to paint names on their boats until after clearing this obstacle, which they saw as the first major test on the river.

The Colorado River Storage Project

Developers have a poignant habit of naming their projects for the things they destroy. Thus, in November 1962, as a 500’ high plug of concrete in upper Red Canyon inundated 90 miles of upstream river corridor, Flaming Gorge Reservoir was born in memoriam behind the Flaming Gorge Dam. Along with Flaming Gorge, the project flooded Horseshoe and Kingfisher Canyons, plus the notorious Ashley Falls just a few miles above the dam.

The Flaming Gorge Reservoir was born of the Colorado River Storage Project, which some also credit with starting the modern grassroots environmental movement. The program encompassed multiple major dams, initially including a site in the heart of Dinosaur National Monument. The audacious proposal caught the attention of environmentalists across the country, who successfully lobbied Congress to eliminate the Dinosaur site, establishing a precedent to keep such developments out of the National Park System going forward. But activists were forced to settle for a targeted victory, leaving the Flaming Gorge project and its more famous sibling, the Glen Canyon Dam at Lake Powell, to proceed.

How Did the Dam Change the River?

The Green River is fed largely by snowpack that accumulates high in the mountains all winter and then rushes down the drainage with spring snowmelt. The graph below illustrates how the dam altered that pattern starting in 1963.

During regular spring floods, the riverbed would experience a natural reshuffling, shifting, and meandering over a relatively wide corridor. Without floodwaters, the river can’t wash over its banks, so it sticks to the same channels year after year, making them deeper and narrower. The reduced disturbance of the river corridor encourages the growth of thick vegetation like tamarisk, which further reinforces the banks against the natural erosion cycle. In addition to changing the structure of the river channel, the Flaming Gorge project causes the settling of sediment in the reservoir, and the cooling of the water as it stacks up in a pool hundreds of feet deep before continuing downstream.

A less dynamic riverbed and the colder, clear water coming from the dam proved too much for the native fish to survive: the environment they evolved in was effectively gone. However, the new conditions were perfect for the introduction of non-native trout, which were a big hit with anglers. It was the trout fishery that inspired the first wildlife-oriented updates to dam operations. In 1974, the Utah Division of Wildlife Resources (DWR) negotiated a minimum release of 800 cfs to support “fishing, fish spawning, and boating” on the river. Next, In 1978, a “selective withdrawal structure” was added to allow the passage of water from different elevations of the reservoir, which permitted fine-tuning of the ideal trout temperature behind the dam. The trout industry still thrives today, where the fish can be caught for some 50 miles below the dam.

What Does This Have to Do with Rafting?

OK, it’s true that Holiday doesn’t run fishing trips (although fishing is encouraged on some routes), but the releases from Flaming Gorge Dam flow through MOST of the river sections we travel: Lodore, the Yampa below Echo Park, Desolation, Labyrinth, and even Cataract Canyon almost 500 miles downstream. Decisions at Flaming Gorge impact all of these areas, including some ways you may not realize:

Campsites: Spring flooding on the Colorado Plateau lets rivers overflow their banks, scrubbing them clean and encouraging growth like cottonwoods- majestic trees that are specifically adapted to floodplain life. Tamed, channelized rivers have steeper, brushier banks, which aren’t as much fun for hauling dutch ovens or throwing horseshoes! The release plans of the dam can either amplify or reduce spring high water events.
Wildlife: Responsible water management supports the habitat of all the native species we enjoy spotting on the river, like playful beavers or nimble bighorn sheep. It’s true that high spring flows can encourage some extra summer mosquitos in Desolation Canyon, but these feed the fish below us and the birds and bats in the air—everything is connected!
Knots: On your next trip, ask your guide to show you how they tie up their boat at night. We use specific knots that can easily slide to move our rafts up and down the shore with changing water levels. On a normal day in Lodore, the flow can double and then go right back down to where it started every 24 hours, because this is the first stretch of river below the dam, where all of the water is subject to the daily cycle of hydropower generation.
Big Water: If double flows sound dramatic, wait until you ride a spring release through Lodore, with 10 times more water than the normal baseline! This makes for big splashy fun through the rapids, and that water just keeps going to add a boost in all the sections downstream as well.
The Confluence: If you join us for an expedition down Lodore or the Yampa, you’ll float through a magical place called Echo Park, the heart of Dinosaur National Monument, which serves as a sort of living museum of natural vs. regulated rivers. This is where the water from Flaming Gorge Dam flows out of Lodore Canyon and meets the undammed Yampa River. In the spring, even a full release from the dam is dwarfed by the Yampa, which often flows at double or triple that rate. In the summer, the Yampa is a trickle compared to the steady release schedule of the dam, and you can see a distinct boundary between its warm, brown current and the clear, cold waters of the Green (see the river flow graph above). Even this confluence is carefully engineered in response to native fish recovery efforts: the dam selectively releases water that keeps the Green River here within 9 degrees of the Yampa, to reduce the risk of cold shock in native fish that move between the two rivers in their natural life cycle.

High Water Spring

Didn’t the dam put an end to high water? Well, as our scientific awareness and national ethics around the environment have evolved, so have the water releases from the dam. The river flow graph above averages data from 1962 until about 2000, and things have changed since then to restore a more natural pattern to the river. To explain that properly, it’s worth mentioning some specific developments in environmental policy.

During the 1960s, the dam simply maximized the economics of power generation, pumping lots of water through the turbines when energy prices were high, and saving all but a trickle when prices dropped, waiting to capture the high-price periods later in the day or week. Even into the 1980s, trout were the only wildlife getting specific accommodations from the dam operations.

1973 however, saw the passage of the Endangered Species Act, landmark federal legislation that still functions today as the primary protection of biodiversity in the United States. The Endangered Species Act suddenly placed a legal obligation on all federal agencies to – you guessed it – stop endangering the existence of plant and animal life in the country. In the case of the Flaming Gorge project, this meant figuring out how to improve living conditions for the remaining populations of native fish downstream, while ideally preserving the popular trout resource, managing water supplies for drinking and agriculture, and producing profitable electric power. The needs of native fish were not very well understood in the 70’s, and many dedicated experts are still working to refine that knowledge today. So, updating the dam for these considerations has occurred through a few major milestones over several decades:

1980: The Bureau of Reclamation enters formal consultation with the Fish and Wildlife service on the Flaming Gorge Project to fulfill their obligations under the Endangered Species Act.
1985: Reclamation and Fish and Wildlife sign a “interim flow agreement” based on ecological studies dating to 1979. The flow agreement is the first operational update to accommodate native species, and sets some caps on the water released for the dam, under the theory that low flow at certain times is helpful to certain native fish. Further research and experimentation with various flow levels is also prescribed, but there’s still no regular spring peak under this agreement.
1988: Upper Colorado River Endangered Fish Recovery Program (The Recovery Program) is established as a unique partnership of local, state, and federal agencies, water and power interests, and environmental groups working to recover endangered fish in the Upper Colorado River Basin. Today the Recovery Program covers over 2,000 projects and over 2.8 million acre-feet of water used in Colorado, Utah, and Wyoming.
1992: Fish and Wildlife publishes a “Biological Opinion” that concludes historic operations of Flaming Gorge Dam (i.e., dam operations prior to 1992) jeopardized the continued existence of endangered fishes in the Green River. Recommendations include high release volumes in the spring corresponding to the spring peak of the Yampa River, which meets the Green 65 miles downstream in Dinosaur Monument. The report recognizes that the unregulated Yampa inflows are critical to maintaining endangered fish habitat, and that above that confluence, where most Green River water comes from the dam, native fish habitat is effectively unrecoverable.
2000: Further studies culminate in an updated Flow and Temperature Recommendations document from the Recovery Program. The recommendations include various updates to the 1992 protocols, including at least two that still distinctly impact whitewater boating today. First, the spring peak volume was increased from full power plant capacity (4600 cfs) to full bypass and spillway capacity (8600 cfs). This high volume causes some loss of revenue to the dam operations, as the bypass volume doesn’t travel through the hydroelectric turbines, and can’t be used for making power. However, the extra release creates exciting spring runs through Lodore Canyon. Second, the limit on daily change in water level caused by hydropower cycles was set at 0.1m, measured below Dinosaur Monument at Jenson, Utah. Notably, there are no limits on fluctuations in Lodore, where all the water comes from the dam, so the daily water level changes are quite noticeable to people camping and boating in that stretch.
2005: After years of further coordination and study, the Bureau of Reclamation formally approves the 2000 Flow and Temperature Recommendations, which still govern dam operations today. Biological research to perfect these recommendations is ongoing by the Recovery Program.

Current Operations

So, do the 2000 Flow and Temperature recommendations tell us what the dam will do? Well, not quite. There are a number of different, sometime competing, priorities that the Bureau of Reclamation juggles when deciding how to manage any given hour of water flow through the dam:

2000 Flow and Temperature Recommendations: This document sets guidelines to support the recovery of native fish, but still provides flexibility to Reclamation. All of the targets are also sensitive to hydrologic conditions. In other words, the water released from the dam will generally depend on the amount of water naturally flowing into the reservoir behind it, and this is reassessed on a monthly basis. For example, in an “average” hydrologic year, the document allows average daily release volumes from 800 to 2,200 cfs during the summer and fall seasons – a pretty large range of flexibility.
Recovery Program: This group conducts constant endangered fish monitoring and research, and makes requests for specific experimental or proven beneficial flows that Reclamation can implement within whatever flexibility it has under regulations and competing requests.
Western Area Power Administration (WAPA): WAPA transmits and markets all the power that is generated at Flaming Gorge, delivering it to electric customers. They make operational requests to Reclamation to help maximize the profitability of power generation.
Utah Division of Wildlife Resources: Monitors the tailwater trout fishery and submits requests to benefit that resource.
Other States and Resources in the Colorado River Watershed: Since 1922, The Colorado River Compact and numerous follow-up laws and agreements have managed the sharing of Colorado River water between approximately 40 million people across 7 states. Starting in 2019, a “Drought Contingency Plan” for the whole watershed has directly impacted Flaming Gorge, generally mandating extra release volumes to support rapidly-shrinking Lake Powell downstream.
The General Public and Outdoor Recreation Industry: the management of the dam is an open process for the general interested public. 2023 is shaping up to be a year with lots of water, which, counterintuitively, means Flaming Gorge might release less to replenish the reserves it has been sending downstream in recent years. Holiday’s own Tim Gaylord reminded stakeholders in a March 2023 planning meeting that extreme low water in Lodore can impair whitewater boating, an important business for many local companies!

The list here is a serious oversimplification of the factors affecting water running through the dam every day. There are a multitude of complicated considerations for every single group I’ve named, and several avenues for sorting out all these interests every year. The main venues for discussion are the technical and non-technical working groups, which ultimately culminate in Reclamation’s Annual Operation Plan. Check out this blog post for an inside look at some of the conversations and debates that play out in these meetings.

The Modern River

Ultimately, there is really just one way for us river runners to know for sure what’s happening with the dam: check the gauge of real-time flow. The topics we’ve covered in this blog can help demystify at least a few features of the graph over the course of a season. The summer of 2022 is shown as an example below.

Late Winter Low Flow: Starting on the left side of the graph, April into May releases are steady around 850 cfs. This is largely to maintain reservoir levels until spring runoff begins, and Western (WAPA) has prioritized other seasons for generating higher-value electricity.
First Peak: Marked by the first red arrow from the left, not much of a peak, actually just two consecutive evenings where releases are increased at the request of Utah Wildlife Resources, so they can navigate the trout fishery in jet-boards for scientific sampling.
Regular Hydropower Releases: Starting in early May, releases fluctuate about 1000 cfs per day, generating power at the most profitable hours while maintaining the 0.1m limit on daily fluctuations downstream at Jensen. The graph looks like the teeth of a comb leading into the second peak and continuing for the rest of the season.
Second Peak: second arrow from the left, this is the big spring release. For 2022, it was specifically timed to match the hatching of the eggs of the endangered razorback sucker (an native fish). The fish larvae ride the spring peak into floodplains off of the main channel, which have better food sources and warmer water temperatures to support growth in their critical first year of life. The larval monitoring and spring peak scheduling request are managed by the Recovery Program.
Third Peak: third arrow from the left, this is smaller than the big spring peak. It uses only the powerplant (not bypass) capacity of 4600 cfs, and is called the smallmouth bass flow spike. This peak is also requested and coordinated by the Recovery Program. The spike does not support smallmouth bass, which are an invasive species and aggressive predator of native fish. Instead, this is actually designed to sweep bass eggs and larvae out of their nests on the river bed, which helps other species thrive.
Summer Ramp-Up: the enlarged portion of the graph in mid July shows how the dam gradually starts releasing more, taking several days to make the shift. By the end of the change, it is spending more time near 2000 cfs than 1000 cfs, which increases the overall average flow. This adjustment requires several days because the 2000 Flow and Temperature Recommendations set limits on how much the average flow can change from day-to-day. The release volume, which exceeds the normal amount for the relatively dry year, was determined by the 2019 Drought Contingency Plan, to support Lake Powell. The date of the ramp-up, however, is optimized to support the endangered Colorado Pike-minnow, which needs a steady supply of water in the late summer, as requested by the Recovery Program. Further, the daily low flow periods are concentrated in the overnight hours, when summertime air conditioning demand is the lowest, and regional energy prices are lower as a result.

What About This Year?

The single best guide for future releases is the annual Flaming Gorge Operation Plan, published by Reclamation. The 2023 plan was released in May. As we finalize this blog post in July of 2023, we’ve already seen some very low water in the spring, which has restored the level of Flaming Gorge reservoir to about 90% full. We saw a big water release of 8600 cfs for over a week in early June, which provided huge exciting waves for a few lucky rafting trips. Biologists from the Recovery Program have recommended against a smallmouth bass spike this year, since this tends to occur after the Yampa has dropped out, but the late runoff season has put that date too close to the start of Colorado Pike-minnow spawning. Another large release would have severe negative impacts on a sensitive time in the life cycle of that endangered fish. However, extreme low flows are also harmful to the Pike-minnow, so Flaming Gorge started ramping up releases on July 19 to provide optimal conditions for this keystone fish. This will keep daily averages around 1800 cfs for the rest of the summer, pending the Yampa river contributions towards the goal of 2200 cfs below the confluence. This goal was determined by hydrologic conditions in the spring, confirmed by a public update from Reclamation on July 12, and matches table 7 (p11) of the operations plan linked above. In summary, the amount of water in Lodore will double, making for a few less bumps and sticks on rocks starting in late July!

Conclusions

The Colorado River is one of the world’s most heavily engineered and altered watersheds. Flaming Gorge is just one huge reservoir that is dwarfed by the enormous lakes downstream, to say nothing of the hundreds of miles of canals that drain the river dry for drinking water and irrigation long before it reaches the ocean. The Colorado is also one of the world’s most heavily litigated rivers, with over 100 years of complex and even contradictory agreements governing use by hundreds of separate interest groups. Lately, some observers have speculated that President Biden’s re-election strategy might even affect the management of the current drought crisis, as the key swing states of Nevada and Arizona are especially sensitive to water supplied by the river.

The Flaming Gorge dam can feel like just a pawn in a huge web of technical and political systems reaching across the whole country, on a river that’s lost its original wild glory. Even while this is true, it’s also true that our individual voices matter, and that our country’s environmental movement has produced some robust protections that seriously constrain the economic operation of the dam in favor of recreating a natural cycle on the river. Although election polls in suburban Phoenix may have a roundabout impact on the water coming from Flaming Gorge, the Endangered Species Act will still influence releases in a way that prioritizes the health of the native ecosystem.

Ultimately, there are no easy answers for river rats just asking when the big water is due. But at Holiday, we’re more interested in big water as a sign that our rivers are healthy and strong, and as a way to get other people caring about that too. The management of the Colorado River is extremely complicated, but we hope this post can aid you on the journey of understanding it. We also hope you’ll join us in speaking up for wild water because none of these decisions is isolated from public opinion!

Luke is a South Carolina native who visited Utah’s canyon county a few years ago, and never found his way home. At this point, he’s fully embraced learning all he can about the vast desert and raging rivers, so he might be here a while. He’s a big fan of riding bikes, eating snickers, finding scorpions, and bringing people along to share in all the adventure!