2017- A Record Year for High Flow?

As I write this, the Bighorn reservoir is at 90% percent full with only 8.8 more feet of water needed to reach full pool, and it is only the end of February.   Working in fisheries below tail water dams for over decade, I fully understand the complications of water storage and allocation for hydropower, irrigation, and flood control, especially in years of drought.  I also understand that under dire water situations, there are going to be years when fisheries, even world renowned fisheries such as the Bighorn, take a hit.  That is simply life in a dammed system – when there’s a lot of water everyone is happy, and when there isn’t enough, we all must make sacrifices.  During times where fisheries take a hit, it may affect a year class or two of wild trout, but over time, the river will recover and so will the fisheries.  Living in an arid region I think all fisherman, for the most part, understand that.

Yet this year, we have no shortage of water and we still find ourselves in a bit of a conundrum.  The Bureau of Reclamation (BOR) manages its water in regards to lake elevation and target dates. The fall reservoir elevation target is in place to make sure there is enough carryover for the next water year to facilitate all water needs.  The spring target date is March 31st, where the goal is to have the reservoir elevation at 3617 ft, or 23 ft. below full pool to allow for runoff and spring precipitation.

Currently it is February 27th and, and we are 14.1 feet above the 3617 target and inflows over the weekend were nearly double what was being released below the dam into the river.  While inflows, as of today, have decreased, we are still apprehensive about having more storage space available to 1. hit the end of March target level, and 2. prevent a very high water year on the Bighorn. With record snowpack already in the mountains, and the high precipitation months still ahead of us, the lake should not be filling and not be 8 feet below full pool.

The below graph shows this year (in black) and the three highest water years of the last 30 years.  While there are quite a few things to say about this graph, the red line is the most notable.  In April the red line drops to 3,608 ft. – which reflects when a flow of 15,000 cfs was being released below Yellowtail dam.  Now consider the black line, which reflects this year- and notice that we are a good 8 feet above what the red line was.  We need to start moving water.


So, why isn’t more water being released?  In talking with BOR, the main reason is because of the ice jams in the Lower Yellowstone.  If you increase flows substantially with significant ice present downstream, water will be dammed and contribute to significant flooding that could damage infrastructures such as personal property, roads and bridges downstream.  Also, a surplus of water now does not indicate a high precipitation spring, so releasing too much water is worrisome for BOR if we don’t have much spring moisture.  However, the months of June and July are considered the high water months on the Bighorn – whether that moisture comes from rain or snowfall, historic data reflects that the Bighorn Basin receives the most water during these months.  In fact, the Alliance has been advocating for March 1 target dates to be brought down to 3611 for the exact situation we are seeing now.  Lowering the target elevation, especially when we have had above average moisture all winter, allows for more storage (in anticipation for the high moisture months to come) and would also help boost winter flows releases which are important for overwintering juvenile trout.  In drought years, we may have to see winter flows decrease to make this deadline if carryover from the Fall target date is not met, but again, that is life below a dam – it is a series of compromises.

The crux of the problem, as with most dams, is that when the Yellowtail dam was constructed in 1967, the fisheries, and how it would be managed, was not considered in its operation plan.  In fact, the wild trout fishery was created in response to this dam was in the eyes of BOR, a “perk” may you say or “byproduct” of dam construction.  They had no vision of it taking off as blue ribbon trout water, and surely did not foresee managing it as a wild trout destination as an objective. However, in 2008 Montana Fish Wildlife and Parks began assessing operating strategies for Yellowtail Dam to determine if the fisheries in the Bighorn River could be improved while maintaining Bighorn Reservoir elevations and presented an opportunity to BOR to further model new strategies that benefit both the Bighorn reservoir and the River downstream.  In 2010, BOR reported results of their computerized model of Yellowtail dam which was designed to develop operating criteria to balance often conflicting recommendations by stake holders in Wyoming and Montana.  This effort has encouraged BOR to try and maintain more consistent flows, try to keep winter flows above 2500 cfs and most importantly, encourage consideration of the river life below the dam, but again, all this is second to a steady, full reservoir that facilitates the primary objectives of hydropower, flood control and lake recreation.

So here we are today.  We have a dam that created not only a river we love, but an important economic resource to the state of Montana but that BOR has no legal obligation to protect outside of what’s required from its original operation plan.  We have an exceeded target date, and yet not sufficient action to release more water.

From the Alliance’s stand point, we need to see more water released now.  More water will help clear out the system and gravels for spawning, increase adult rainbow movement upstream to start spawning, and help alleviate high summer flows that could flush and kill pre hatch rainbows.  High flows now will saturate side channels, increasing spawning grounds, which with excess water, should be able to remain saturated through the rainbow egg incubation stage.  Most importantly, (to BOR) it will facilitate storage for upcoming spring moisture.  For the months of January and February we were pleased at the flow increases made by BOR in response to the snowpack the basin was receiving. In fact, BOR raising flows before the March 31 target date was considered a minor victory that had not been accomplished before.  Yet, as the snowpack kept increasing we kept recommending more releases, which to credit of BOR did occur, but minutely and not enough to prevent what we are seeing today.

From an economic standpoint, we need to release water now to ensure businesses survive the summer.  When flows exceed 8000 cfs on the Bighorn, businesses start taking a hit as rental boats are no longer available to fisherman, access sites such as the Bighorn become difficult to take out from, and ramp infrastructures start deteriorating.  With limited access on the Bighorn as is, this is a serious problem that needs to be considered, especially since the Bighorn is one of the state of Montana’s biggest river money makers- bringing in an estimated 45 million dollars each year.

In December of 2016, the Outdoor Recreation Jobs and Economic Impact Act (known as the Outdoor REC Act) was signed by the President of the United States to confirm outdoor recreation industry is a significant economic drive.  This new piece of legislation requires the Department of Commerce, in collaboration with the Department of Interior (BOR) and the Department of Agriculture to assess and analyze the contributions of the outdoor recreation industry, including recreational fishing to the United States economy, meaning that the outdoor recreation economy statistics will be measured in the same way as other business sectors. We are hopeful that this bill will ultimately lead BOR to put more focus into sustaining the economy of the Bighorn River, or at least bring more data to the table on how dam management practices affect the Bighorn fishing economy.

In conclusion, it is looking like a high water year unless mother nature gives us a dry spring, and/or BOR steps outside their comfort zone and releases more water now.  It is also apparent that we need to start looking data, ranging from a long period of time, to determine if the first spring runoff is coming sooner, which is making BOR water management in March more difficult.  While we cannot predict the future (which is half of the problem) we will continue to advocate for flows that benefit the Bighorn trout fishery and its economy.

Anne Marie

Anne Marie Emery
Executive Director
Bighorn River Alliance








2 thoughts on “2017- A Record Year for High Flow?

  1. Harry Piper says:

    Good informative blog on Horn flows, thanks for keeping the faithful in the loop!

  2. Excellent post. I used to be checking constantly this weblog and I’m impressed! Very helpful information specifically the ultimate section :) I care for such info much. I used to be looking for this certain information for a very lengthy time. Thank you and best of luck.

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