The federal Clean Water Act requires that states and tribes restore and maintain the chemical, physical, and biological integrity of the nation's waters. States and tribes must adopt water quality standards necessary to protect fish, shellfish, and wildlife while providing for recreation in and on the waters whenever possible.

Section 303(d) of the Clean Water Act establishes requirements for states and tribes to identify and prioritize water bodies that are water quality limited (i.e., water bodies that do not meet water quality standards). States and tribes must periodically publish a priority list of impaired waters, currently every two years. For waters identified on this list, states and tribes must develop water quality improvement plans known as total maximum daily loads (TMDLs) that establish allowable pollutant loads set at levels to achieve water quality standards.

Following analysis of data and modeling results, 18 water bodies in the subbasin were verified to be water quality limited by at least one pollutant: eleven due to temperature, eight due to sediment, and one due to bacteria. The temperature TMDLs were deferred by the state until state temperature criteria are fully examined. The sediment limitations in the upper two segments of the Coeur d'Alene River are addressed in sediment TMDLs for the North and South Forks Coeur d'Alene River. Lake Creek, which is sediment limited, is wholly on the Coeur d'Alene Reservation, so it is not included in this TMDL. The five remaining segments limited by sediment are addressed here, as is the one segment limited by bacteria.

The impacts of heavy metals are addressed in separate documents. This TMDL deals solely with non-metallic pollutants.