Surface Water Designated Uses
Assessing the health of a waterbody starts with determining what types of activities the water should support, also commonly referred to as a waterbody's "Designated Uses." Under the Clean Water Act, Wisconsin waters are each assigned four "uses" that carry with them a set of goals: Recreation, Public Health and Welfare, Aquatic Life and Wildlife. Water quality criteria are developed to protect specific uses.
Most surface waters are considered appropriate for recreational use, which includes activities that involve contact with water such as swimming, water skiing, canoeing, kayaking, scuba diving, wading, boating, fishing and hunting.
Public Health and Welfare Use
The Public Health and Welfare Use protects for multiple avenues of human interaction with surface waters:
- incidental contact and ingestion;
- fish consumption; and
- public drinking water supply.
All surface waters are considered appropriate to protect for incidental contact and ingestion by humans as well as human consumption of fish. The Great Lakes as well as a small number of inland waterbodies are also identified as public water supplies and have associated water quality criteria to ensure that water drawn from these sources will be safe for human consumption after drinking water treatment
Aquatic Life Use
All surface waters are considered appropriate for the protection of fish and other aquatic life. Surface waters vary naturally with respect to factors like temperature, flow, habitat and water chemistry. This variation allows different types of Aquatic Life communities to be supported.
Wisconsin's Aquatic Life use designations are categorized into the following subcategories as defined in s. NR 102.04(3), Wis. Adm. Code.
- Coldwater community*
- Limited Forage Fish community
- Warmwater Sport Fish community
- Limited Aquatic Life
- Warmwater Forage Fish community
Classifying waters into these subcategories involves science that reflects an evaluation of the resource and its natural characteristics. The department is currently in the process of proposing revisions to these five Aquatic Life designated use subcategories through a rulemaking effort.
All surface waters are considered appropriate for the protection of birds and mammals that rely on the waterbody for food and water.