May 09, 2023
Starting on May 10, the Bureau of Reclamation (BOR) will reduce the water flow from Jackson Lake Dam in the Upper Snake River to 280 cubic feet per second (cfs). The move is intended to prevent water from spilling over Milner Dam downstream in Idaho, essentially wasting water that is owed to Idaho ranchers via irrigation, due anticipated high flows from above-average snowpack. The reduction should last for six to eight weeks.
BOR, which operates Jackson Dam and others downstream, prefers to keep this excess runoff in Jackson Lake since it currently has the capacity. Reservoirs downstream are near full and water lost to spilling over would be "lost" to irrigators this season.
BOR threatened to drop Snake River flows to 50 cfs to accomplish this, but Wyoming Game and Fish managers balked since the minimum flow required to maintain the fishery below the dam and water at Oxbow Bend has been determined to be 280 cfs. Oxbow Bend is important habitat for native bluehead suckers and Snake River finespotted cutthroat trout.
“This decision by BOR has the potential to impact spawning native fish, anglers and recreational users and visitors at Wyoming’s beloved Grand Teton National Park,” Game and Fish Director Brian Nesvik said. “Reducing flows during a year when we have significantly more water available than normal is hard to comprehend and Wyoming cannot support this reduction. The State of Wyoming is calling on BOR to develop alternative solutions quickly to keep flow rates at the minimum level to conserve wildlife.”
The state is subsequently being strong-armed into utilizing its water rights in order to keep the flow at 280 cfs–rights that would run out after about 5.5 weeks. If reduced flows are still required at that point, BOR could still drop flows from Jackson Dam to 50 cfs for the remainder of the 6 to 8 weeks–low flows not seen in over 40 years. Using up all of Wyoming’s water rights now could also have consequences for flows later in the year.
“Ideally, we would be mimicking spring hydrographs and having flushing flows that mimic runoff this year,” said Leslie Steen, northwest Wyoming program director for Trout Unlimited in a Jackson Hole News and Guide article by Billy Arnold. “We’re in the opposite scenario, where we’re trying to keep the bare minimum amount of water in the river.”
The State Engineer’s Office, Wyoming Water Development Office and Game and Fish have stated that they remain committed to working with BOR to maintain flows at levels that will avoid negative impacts to the fishery. State leaders are also working in good faith with senior officials in the Department of Interior to find a mutually agreeable path forward that protects critical wildlife habitats.
“Right now it feels like this is a Band-Aid on a gaping wound,” Orion Hatch, Snake River Fund executive director said in the article. “We need our legislators, our conservation-minded NGOs to come to the table and find a long-term solution to prevent this from happening again.”
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