SHERIDAN — Montana and Wyoming state officials have been in communication daily since Montana officials made an April 1 call on the Tongue River and its tributaries to fill the state’s Tongue River Reservoir.
Wyoming State Engineer Brandon Gebhart said the states are regularly reevaluating the need for the call, especially in light of snow and other precipitation arriving since April 1. However, he said neither state is rushing to lift the call.
“We realize that the recent storms have maybe changed the hydrologic conditions,” Gebhart said. “(Montana officials) are actively working right now to reevaluate their process with this new information to see how or if that impacts them lifting the call… The one thing we’re being cautious about is that we don’t want to lift the call just to reinstate the call at a later date.”
The Tongue River basin has been experiencing drought conditions over the past year with below average winter snowpack and streamflow conditions, which led to Montana’s call, said Division II Water Superintendent David Schroeder. Montana’s reservoir needs roughly 27,800 acre feet of water from the Tongue River basin to be filled, Schroeder said.
Until the reservoir is filled — or the call is lifted by Montana — filling the reservoir will become the second priority for the water of the Tongue River and its tributaries. First priority will be all pre-1950 water rights in Wyoming. All post-1950 water rights in Wyoming will be regulated off or prevented from turning on until Montana’s call is completed, Schroeder said.
Schroeder said he didn’t expect the call to have a significant impact on landowners with post-1950 rights given how early the call was happening in the irrigation season.
A call on a river or drainage system is a legal mechanism to order water conservation actions to help ensure minimum, legally required flows to users with senior water rights — typically for irrigation. In the event of a potential water shortage, those with junior rights — post-1950 Wyoming water rights holders, in this case — can be ordered to forgo diverting water to help ensure senior-rights holders downstream — Montana in this case — get their full allotment.
Montana made its call through the Yellowstone River Compact — an interstate agreement entered into by Montana, Wyoming and North Dakota in 1950. According to the U.S. Geological Survey, the compact was created to provide for an equitable division of the waters of the Yellowstone River and its tributaries, while encouraging the beneficial development and use of the basin’s waters and furthering intergovernmental cooperation.
This is not the first time Montana has made a call on the Tongue River under the compact — it happened most recently in 2015 and 2016, Schroeder said. However, this is the first time a call has been made since the resolution of Montana vs. Wyoming, a U.S. Supreme Court case that stretched on for 11 years between 2007 and 2018.
In the case, Montana argued Wyoming violated the Yellowstone River Compact by permitting citizens to employ more efficient irrigation systems, causing Montana to receive less runoff water than the state had originally received. The court found Wyoming had violated the compact in two of the years claimed by Montana — 2005 and 2006 —and Wyoming was ordered to pay more than $67,000 in damages to Montana.
Included in the final judgment was a decree outlining how the call process should work in the future. These rules are being followed by both states in the current call, said Chris Brown, senior assistant attorney general for the state of Wyoming.
“The last call was in 2016, and when that call was made, the tools in the decree had not been established at that point,” Gebhart said. “So I think we have much more guidance and knowledge of how we’re going to handle calls going into the future.”
Gebhart noted the years-long litigation created tension between the two states, and departmental turnover led to a loss of institutional knowledge in both states. Despite that, Gebhart said his office is dedicated to keeping open lines of communication with Montana and to honor the spirit of the compact.
“We’ve committed to working more closely together, and I think that’s the first step to making this whole process better,” Gebhart said.