WRM 2000 Legal aspects

Dam basics: Legal definitions

The following legal definitions and requirements relating to dams are those specified by the Wisconsin State Statutes and Wisconsin Administrative Codes. References to the appropriate statute or code are listed in parentheses and the reader is encouraged to consult them to view them in their entirety.

What is a dam?

Although the public has developed its own definition of a dam, there are several strict legal definitions. A dam is any artificial barrier, together with appurtenant (relevant or applicable) works, that is built across a waterway and that has the primary purpose of impounding or diverting water (Wis. Admin. Code Section NR 333.03.02, 2000). More specifically, a large dam (fig. 1) is a dam that has either a structural height of more than 6 feet and a maximum storage capacity of more than 50 acre-feet or a structural height of 25 feet or more and a maximum storage capacity of more than 15 acre-feet (Wis. Admin. Code Section NR 335.03.12, 2000).

Figure 1. The former Ward Dam on the Prairie River, Wisconsin, represented a large dam. (Photo courtesy of Stephanie Lindloff, River Alliance of Wisconsin.)

A small dam has dimensions that are less than those outlined for large dams (fig. 2).

Figure 2. The Linen Mill Dam on the Baraboo River, Wisconsin, represents a small dam.

Each classification of dam size has different statutory requirements for design, maintenance, inspection, and so forth.

Who is a dam owner?

A dam owner means any individual, partnership, public utility, company, cooperative, trust, corporation, association, state or interstate agency, city, village, county, or special purpose district, such as a drainage district or a public inland lake protection and rehabilitation district, that has title (ownership) to a dam or to the specific parcel of land on which a dam exits (Wis. Admin. Code Section NR 333.03.14, 2000; see also Wis. Admin. Code Section NR 335.03.19, 2000).

Responsibilities of the dam owner

Owners of dams are required to preserve public rights in navigable waters, including those created by dams (that is, impoundments), and to provide a means of maintaining dams and the developments that have been made adjacent to the impoundments (Wis. Stats. Section 31.14(1), 1997-98). Similarly, the owners must, as specified by statute, maintain and operate all dams and other equipment required by the Wisconsin Department of Natural Resources for the protection of public rights in navigable waters, and for the preservation of life, health, and property, in good repair and condition, and shall not…remove or destroy the structure or any part of it unless the Wisconsin Department of Natural Resources have approved such a removal in writing (Wis. Stat. Section 31.18(1), 1997-98). Dam owners are ultimately responsible for any damages caused by the improper operation and maintenance of their dam structure.

Dam inspections should be completed by the Wisconsin Department of Natural Resources every ten years for large dams (Wis. Stat. Section 31.19(2), 1997-98), or when the Wisconsin Department of Natural Resources receives a complaint from a municipality or person with property impacted by the dam or impoundment Wis. Stat. Section 31.193), 1997-98). Other conditions may support discretionary inspections by the Wisconsin Department of Natural Resources, and such inspections are determined by the Wisconsin Department of Natural Resources (Wis. Stats. Section 31.19(4), 1997-98). Small dams have no Wisconsin Department of Natural Resources inspection requirement. A notice to repair a small dam is sent only after a complaint is made about the structure or after failure.

Next section: Repair/removal options

URL: http://www.ies.wisc.edu/research/wrm00/legdef.htm