Watershed Approach

In Montana, implementation of the source water assessment program is based on a watershed approach that: 1) identifies SWAP implementation priorities within each major watershed, 2) assigns oversight responsibilities to program staff for source water assessments within each of the major watersheds, 3) tracks program implementation within each watershed.

Major Montana Watersheds Map

Utilizing a watershed approach:

  • Allows easier management by dividing the state into smaller units (see Fig 1)
  • Fosters coordination with other programs at DEQ
  • Encourages coordination of PWS management plans within watershed sub-areas
  • Helps meet the federal requirement that the state use an integrated watershed approach that is well integrated with other water or natural resource programs for assessment, protection, and remediation
  • Helps the state effectively incorporate a variety of organizations and interests into its implementation of non-point source activities and projects as required by the federal Clean Water Act.

Completion of Source Water Delineation and Assessment Reports (SWDARs) will be accomplished through the combined efforts of the DEQ source water protection watershed coordinator, participating public water supplies (PWSs), and contractors working on behalf of the PWS.

Yellowstone River Project Area

The Yellowstone River Watershed (YRW) Project Area includes the area south of the Yellowstone River from its headwaters in the Paradise Valley to the Montana-North Dakota border. The watershed is comprised of about 27 sub-basins with more than 400 Public Water Supplies (PWSs). The effort to complete SWDARs for the watershed will focus on sub-basins with large numbers of high priority PWSs. Project areas include the Upper Yellowstone Watershed (Paradise Valley/Gardner area), the Billings area (five large surface water PWSs and other smaller systems), the Tongue and Powder River basins, and 33 schools scattered throughout the watershed. The Source Water Protection Program staff has collected background information for these project areas. We are in discussion with the city of Billings about ways to lead the source water project on behalf of the other surface water system near Billings. For more information on the Yellowstone River Watershed please call Jim Stimson at 406-444-6832.

Western Slope Watershed Project Area

The Western Slope Watershed (WSW) Project Area includes the area west and north of the Continental Divide from the Canadian Border in Glacier National Park to Chief Joseph Pass south of Darby. The watershed is comprised of the drainage basins of the Kootenai River, The Upper Clark Fork and Lower Clark Fork River, and the Flathead River. Within the Western Slope Watershed there are more than 927 PWSs. These PWSs use both surface water and groundwater as sources for their drinking water with a diversity of aquifer types present within these watersheds. Please contact Jeffrey Herrick at 406-444-1595 for more information on the Western Slope Watershed.

Upper Missouri River Watershed

The Upper Missouri River Watershed (UMRW) is located in west-central Montana. The watershed is comprised of 13 sub-basins with more than 500 PWSs. The effort to complete SWDARs for the watershed will focus on sub-basins with large numbers of high priority PWSs. The largest project areas in this watershed include the Upper Missouri Watershed (Helena & surrounding area), Gallatin Watershed (Bozeman & surrounding area), and the Upper Missouri-Dearborn Watershed (Great Falls & surrounding area). There are approximately 26 schools within the UMRW. For more information on the Upper Missouri River Watershed please call Carolyn DeMartino at 406-444-0820.

Lower Missouri Watershed

The Lower Missouri Watershed encompasses the Missouri River watershed from the Marias River confluence to the North Dakota border. Approximately 350 PWSs are located in 39 sub-basins in the watershed. The Lower Missouri Watershed is broken up into 12 project areas based on regional geology and geography. Source Water Protection Program staff are currently collecting background data and information for the completion of SWDARs for PWSs located in the Wolf Point, Poplar, and Culbertson areas. For more information on Source Water Protection activities in the Lower Missouri Watershed, please contact Eric Sivers at 406-444-0471.