Official Government Website

Regional Water Quality Plans and Reports

This page presents subbasin assessments (SBAs) and/or total maximum daily loads (TMDLs) that have been completed in Idaho water bodies. Click on a region for an overview of the subbasin. Access the statewide list of subbasins on our Total Maximum Daily Loads web page.

  • Boise
  • Coeur d'Alene
  • Idaho Falls
  • Lewiston
  • Pocatello
  • Twin Falls

The Boise Region is comprised of 21 hydrologic subbasins which hold within their boundaries nine major river drainages: Snake, Payette, Weiser, Boise, Salmon, Owyhee, Bruneau and Jordan rivers. The Boise Region also has 15 of the 34 degraded ground water Nitrate Priority Areas in Idaho. The water quality staff at the Boise Regional Office addresses the multitude of environmental issues impacting ground and surface water through fact-based science and collaboration with local stakeholders and other state and federal agencies. 

The Coeur d'Alene Region is unique in many ways. First, it shares a border with two states (Montana and Washington), Canada, and three Indian tribes. Since water flows with no regard for humanmade boundaries, staff from multiple agencies and countries frequently collaborate on water quality issues. Second, the region's three large and many smaller lakes are the basis for much of the region's economy. Simultaneously using and protecting these lakes creates both opportunities and challenges. Third, the region overlies Idaho's only "sensitive resource aquifer": the Rathdrum Prairie Aquifer, which provides the sole source of drinking water to nearly 500,000 residents in Idaho and Washington.

The Twin Falls Region is composed of 8 hydrologic units including Lake Walcott, Raft River, Goose Creek, Mid-Snake, Salmon Falls Creek, Camas Creek, Little Wood River, and the Big Wood River. The region is composed of several ecosystems including the High Desert, the Snake River Basin, and the Rocky Mountains. Included in the Twin Falls Region are many unique water bodies such as Silver Creek, a spring-fed, blue-ribbon trout stream, the Big Wood River which flows through the famous Sun Valley area, Shoshone Creek, a large high desert stream that flows from Idaho into Nevada, and the Mid-Snake River which irrigates farmland and is home to a large number of aquaculture facilities in the Magic Valley. Many reservoirs used for irrigation, hydroelectric power, as well as offering sportsmen and recreationists an abundant amount of activities such as fishing, waterfowl hunting, water skiing, canoeing, and kayaking lie in the region as well. These reservoirs include Salmon Falls Creek, Lake Walcott, Goose Creek, Magic, Little Wood, and Mormon Reservoirs.

There is no information available at this time. Visit our Total Maximum Daily Load surface water page for more information about Idaho rivers.

Bear Lake Real-time Water Quality Data and Lake Levels

Regional Water Quality Reports

Visit our Total Maximum Daily Load surface water page for more information about Idaho rivers.

Monitoring Reports

Visit our Total Maximum Daily Load surface water page for more information about Idaho rivers.

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