The Federal Clean Water Act, 1977, (CWA) provides the primary framework for the protection of surface water in the United States. This federal statute creates the system by which each state or tribe can establish water quality standards for their steams, rivers, lakes, and reservoirs. These standards are, however, subject to acceptance by the United States Environmental Protection Agency (EPA).  Water quality standards often are expressed using the term “Total Maximum Daily Load” (TMDL) whcih means the maximum amount of pollutant, such as phosphorous, that a water body can receive and still meet water quality use standards.

To meet the water quality standards set, the water quality must be able to support the designated use of the water. (This is often referred to as the “beneficial use” of the water.) For example: states will set realistic criteria or standards when surface water is going to be used as a private or public water supply. These standards are designed to protect the water so that it can be used for a water supply.

When the water conditions do not meet the established standards, the state declares the water to be “impaired” and reports these “impaired” waters to the public and to the EPA in accordance with section 303 of the Clean Water Act. It is also determined what must be done for the water to meet the established designated use standards. For example: when elevated levels of the nutrient phosphorus exceed established standards necessary to protect the water, then the water is declared impaired because of excess phosphorus. In addition, the amount of phosphorus reduction necessary to meet water quality standards is determined. 

Currently recognized designated or beneficial uses for waters in the watershed include: public and private water supply, fish and wildlife propagation, agriculture, hydropower, primary body contact recreation (such as swimming), secondary body contact recreation (such as boating or fishing), and aesthetics. Criteria are established to determine what is necessary for attainment of each beneficial use. Physical, chemical, and biological data on rivers, streams, and lakes obtained primarily through “use attainability analyses” are used to ascertain the condition of individual waters, to determine appropriate beneficial uses, and to set realistic standards to protect them.

The EPA appears to be shifting to a watershed-wide approach to watershed management from its previous program-by-program, source-by-source, and pollutant-by-pollutant approach. Under the watershed approach equal emphasis is placed on protecting healthy waters and restoring impaired ones. A full array of issues are addressed, not just those subject to CWA regulatory authority. Involvement of stakeholder groups in the development and implementation of strategies for achieving and maintaining water quality is another hallmark of this approach.

The watershed approach is a coordinating framework for environmental management that focuses public and private sector efforts to address the water-related problems within geographic areas. The watershed approach is commonly characterized by four principles: a) well integrated partnerships, b) a specific geographic focus, c) driven by environmental objectives and by strong science and data, and d) coordinated priority setting and integrated solutions.