by Laura Collins
Clark Fork Coalition’s Exempt Well Dashboard tracks exempt wells in the Bitterroot and Missoula aquifers.
Across Montana, the quiet spread of exempt wells is creating a big problem for our rivers, streams, and drinking water. Under current law, these small wells, originally intended for single homes or limited agricultural use, can be drilled without a water right permit. But developers have long used them to provide water to large subdivisions, each new home adding one more straw into the same shrinking aquifer.
To address this growing challenge, MEIC has joined with the Clark Fork Coalition and National Trout Unlimited, represented by the Western Environmental Law Center, as well as municipalities, developers, and agricultural water users, to file a legal challenge against the Montana Department of Natural Resources and Conservation (DNRC) and the State of Montana to close the exempt well loophole due to its impact on constitutionally-protected water rights.
Water rights are protected under the Montana Constitution and the Water Use Act. However, exempt wells are not subject to the water rights permitting process. The exempt well law incentivizes new groundwater development outside of the rigorous permit process, which has led to the rapid conversion of agricultural lands into poorly-planned development, loss of water for instream flows and traditional uses, and other adverse impacts to impaired surface waters.
Exempt wells are often paired with septic systems, which leach nitrogen and phosphorus into groundwater. Over time, that pollution seeps into rivers and lakes, triggering toxic algal blooms and threatening both wildlife and human health. The result is widespread groundwater depletion, polluted lakes, and impaired rivers and streams.
This exemption leaves water rights holders zero recourse to exercise and defend their water rights. The exempt well law violates Montana’s constitutional water rights protection provisions and prevents DNRC from protecting these rights. This isn’t just bad policy. It’s a blatant violation of the fundamental rights of all Montanans who depend on clean and plentiful water.
Montana’s Constitution guarantees every person “the right to a clean and healthful environment” and requires the state to “maintain and improve” it for future generations. Yet, the state has allowed thousands of exempt wells to be drilled without meaningful review, monitoring, or mitigation, failing to prevent harm before it occurs.
Exempt wells not only deplete water needed to sustain fish and rivers, they undermine the rights of senior water users whose legally-protected water rights are being drawn down without notice or recourse. In allowing this unchecked development, the state is additionally violating Montanans’ constitutional rights to due process, and the rights to know and participate in government decisions. Exempt well permits evade public review entirely, cutting water users and citizens out of the process and leaving local governments unable to manage development responsibly.
Montanans are owed better water policy. The right to a clean and healthful environment and the rights of senior water right holders are intertwined. The time has come to fully close the exempt well loophole and craft a better legal framework that recognizes that water is a shared and finite precious resource that must be managed responsibly for present and future generations. All Montanans deserve a voice in determining the fate of our shared precious resources.
This article was published in the December 2025 issue of Down To Earth.
