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Instream Flows

Montana's water law currently provides several mechanisms to directly protect or enhance instream flows or water levels. Provision in law that protect instream flows include:

  1. Pre 1973 statutory directive or authorization to create instream water right on certain key streams. (These existing water rights include "Murphy Rights", "Public Recreational Claims" and Use Rights.), [Learn more]
  2. Post 1973 rights created through the State's Water Reservation process,
  3. Water Leasing, (The Conversions of existing diversionary water rights to instream flow purposes.)
  4. Purchase or service contracts for water delivery from new or existing water storage projects.
Fish Log Participant.

Other mechanisms that help maintain stream flow conditions:

  1. Future Fishery Projects, and
  2. Designation of "Closed Basin" watersheds.

Instream Flow Methods

Murphy Water rights

The Montana legislature recognized the value of leaving water in streams for fish and wildlife purposes in 1969. That year they pass an instream flow protections bill that became law, 89-901 RCM. The resulting statute directed the Fish and Game Commission to make a filed appropriation on the unappropirated waters of twelve blue ribbon streams. These water rights have become known as Murphy Rights, named for the bill's sponsor, James E. Murphy. Learn more

Public Recreation Claims

FWP has also filed Statements of Claim for Existing Water Right –Recreation for "public recreational use" in the Beaverhead 15 KB, Bitterroot 27 KB and Blackfoot/Clearwater drainages 21 KB. These claims are grounded in the legislature's direction to FWP in the 1979 legislative session. That year, Senate Bill 76, among other things, conferred on FWP the responsibility to represent the public for the purpose of establishing any prior and existing public recreation uses in existing right determinations. (See MCA 85-2-223 ) Often the flows and volumes of these FWP claims are linked to fish habitat needs, and the recreational use asserted is primarily fishing and recreational floating. Priority dates for these water rights are very junior (typically near 1970). The validity of these recreational use claims has yet to be fully evaluated in Montana's general stream adjudication.


The concept of state based water reservation was established in the Montana Water Use Act of 1973. Reservations provide an avenue for public entities to seek water for future use or to protect in stream flows or water levels. (See MCA 85-2-316) Instream flow water rights (reservations) have been granted for more than seven-hundred river and stream reaches and are held for the Montanan's by FWP.


The leasing of a water right for instream flow is a voluntary agreement and contract between willing parties. Private parties can develop the terms of a water right lease or exchange between themselves. However before any agreement that moves water or changes is use, place of use or purpose of use is implemented that Change of Use is subject to administrative and public review in a Department of Natural Resources and Conservation proceedings. The following booklet is a brief introduction to some the basic concepts a water user should consider.


Montana water law has long view the storage of water for some beneficial use to a legal diversionary right. Such rights have a definable diversion and control of water. Montana water law has long recognized the practice of transporting stored water from the reservoir to its place of use. Therefore, using stored water to augment stream flows is a practice commonly recognized with many federal storage projects in Montana.

Basin Closure Protection — Closed basin designation is a statutory process defined and governed by MCA 85-2-319 , as "Permit Action in Highly Appropriated Basins or Sub basins". The legislature may be law may preclude permit applications (certain new water rights) or the Department of Natural Resources and Conservation may, by rule, reject permit application of modify or condition permits already issued.

Judical Determinations

FWP has asserted pre-1973 water rights for instream flow and fishery use based on intensive pre-1973 management and restoration activities concentrated on a given stream of stream reach. Some of these water rights have been examined by the Montana Water Court and been subject to and up-held in court decisions in, at least, the first stages of Montana General Stream Adjudication.These adjudication instream flow rights include: