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.
The Boise Region is comprised of 21 hydrologic subbasins that 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.
Visit our Total Maximum Daily Load surface water page for more information about Idaho rivers.