Low flows: A new hurdle for our fisheries

Last summer many fisheries in and around the Gallatin Valley suffered restrictions due to low flow rates and rising temperatures. Montana Fish, Wildlife and Parks (FWP) enforced its drought fishing closure policy aiming to protect the health of our aquatic systems while they were under pressure. According to FWP drought policy, a stream will be closed when flow drops below critical levels for fish, when water quality is diminished or when the high daily water temperature reaches 73 degrees Fahrenheit. Hoot owl restrictions were put in effect on various parts of the Gallatin and many other waterways throughout the state, prohibiting fishing from 2 p.m. to midnight. Fisheries of larger concern, such as the Jefferson and portions of the Shields, Gallatin and Big Hole, were placed under full closure.

Even in areas with no restrictions, anglers were advised to land fish gently and keep them underwater as long as possible during the release. Lower flows in the late summer months created higher water temperatures, causing trout to become more vulnerable to disease and death. With a relatively dry winter so far, anglers can’t help but wonder if we are in store for something similar this summer. Mike Duncan, who works as the management biologist for Madison and Gallatin drainages, spoke with the Exponent on the matter. Duncan currently believes it’s still too early to tell what’s in store for the upcoming months. When asked if he believed the upcoming summer would look similar to the last, Duncan said, “it would only take a couple (of) big storms in March and April to catch us back up to normal.”

Regardless of the results winter brings, the flow rate and warming of our fisheries is not a new concern. Duncan saw noticeable changes in flow rates within his region last summer. He indicated that “plenty of flow and temperature data exist that illustrate decreased or altered flows as well as increased water temperatures in many of our water bodies.” Duncan also noted that he and his colleagues work closely with Northwestern Energy to manage flows out of Hebgen Lake and through the Madison year-round, but that their biggest concern is always the Lower Gallatin. “As we noticed last year, the Gallatin is pretty susceptible to water use and water withdrawals and had extremely low base flow last year.”

Low snowfall isn’t the only concern for our waterways. Bozeman, one of the fastest-growing micropolitan cities in the U.S., relies on this snow we receive for our water supply as well. “The increasing population in the Gallatin Valley is only going to increase water consumption, which will undoubtedly lead to decreased flows in our streams,” Duncan said. “It’s up to the community and our decision-makers to decide how to manage that consumption and best minimize the effects of water use in the valley.” 

As far as what anglers can do on their part when it comes to preserving our aquatic life in years to come; listen to the experts. Sticking to areas less impacted by the drought and avoiding places prone to low flow like the Lower Gallatin are crucial to lighten the load on stressed fish. While inconvenient to those who are looking to score on famous waters, drought closures and regulations are in place to maintain and enhance our waterbodies for years to come.