Regulation of boathouses and houseboats
Wis. Stat. § 30.121
in effect(1) Definition. In this section, the terms “maintain” and “repair” include replacing structural elements, including roofs, doors, walls, windows, beams, porches, floors, and foundations.
(2) Prohibitions. After December 16, 1979 no boathouse or fixed houseboat may be constructed or placed beyond the ordinary high-water mark of any navigable waterway.
(3) Maintenance and repair. The riparian owner of any boathouse or fixed houseboat extending beyond the ordinary high-water mark of any navigable waterway may repair or maintain the boathouse or fixed houseboat if the cost to repair or maintain the boathouse or fixed houseboat does not exceed 50 percent of the equalized assessed value of the boathouse or fixed houseboat and the repair or maintenance does not involve the placement of a floor over a wet bay on or after September 1, 2016. If the boathouse or fixed houseboat is not subject to assessment, the owner may repair or maintain the boathouse or the fixed houseboat if the cost of the repair or maintenance does not exceed 50 percent of the current fair market value of the boathouse or fixed houseboat and the repair or maintenance does not involve the placement of a floor over a wet bay on or after September 1, 2016.
(3c) Exception; certain boathouses. Subsection (3) does not apply to repairing or maintaining a boathouse if the boathouse was in existence on December 16, 1979, and if all of the following apply to the repair or maintenance:
(a) It does not affect the size or location of the boathouse.
(b) It does not result in the boathouse being converted into living quarters.
(c) It does not involve the placement of a floor over a wet bay in the boathouse on or after September 1, 2016.
(3g) Exception; historical or cultural value. Subsection (3) does not apply to repairing or maintaining a boathouse or a fixed houseboat if the boathouse or fixed houseboat has a historic or cultural value, as determined by the state historical society or a local or county historical society established under s. 44.03.
(3m) Exception; certain single-story boathouses. Notwithstanding subs. (2) and (3), a person may construct, repair or maintain a single-story boathouse over an authorized waterway enlargement if:
(a) The boathouse does not extend beyond the ordinary high-water mark as it existed prior to the creation of the enlargement;
(b) The boathouse covers the entire enlargement; and
(c) Living quarters or plumbing fixtures are not constructed in the boathouse.
(3r) Exception; damages after January 1, 1984. Subsections (2) and (3) do not apply to repairing or reconstructing a damaged boathouse if the boathouse was damaged by violent wind, vandalism or fire and if the damage occurs after January 1, 1984.
(3w) Exception; commercial boathouses. Notwithstanding subs. (2) and (3), a person may construct, repair, or maintain a boathouse if all of the following apply:
(a) The boathouse is used exclusively for commercial purposes.
(b) The boathouse is located on land zoned exclusively for commercial or industrial purposes or the boathouse is located on a brownfield, as defined in s. 238.13 (1) (a), or in a blighted area, as defined in s. 66.1331 (3) (a).
(c) The boathouse is in any of the following locations:
1. Within a harbor that is being operated as a commercial enterprise.
2. On a river that is a tributary of Lake Michigan or Lake Superior.
3. On an outlying water and the work is limited to the expansion, repair, or maintenance of an existing boathouse.
(d) The person has been issued any applicable individual permits under this subchapter and is in compliance with any applicable general permitting requirements under this subchapter.
(4) Major repair, abandoned structures and obstructions to navigation. The owner of a boathouse or a fixed houseboat which extends beyond the ordinary high-water mark of any navigable waterway and which is in a major state of disrepair or is a material obstruction to navigation may be ordered by the department to remove the structure from the waterway. The department shall follow the procedures set forth in s. 30.03 (4) (a) for ordering removal of a structure. If such a structure is abandoned and the department, after due diligence, cannot locate the owner, the department shall utilize the procedures set forth in s. 31.187 (1) for removing the abandoned structure.
(5) Applicability. Boathouses or fixed houseboats owned by the state or by local units of government shall comply with this section. This section does not apply to any structure listed on the national register of historic places in Wisconsin or the state register of historic places.
(6) Rules. The department may promulgate rules deemed necessary to carry out the purposes of this section. The rules may not govern the aesthetic features or color of boathouses.
(7) Penalties. Any person who constructs, owns or maintains a boathouse or fixed houseboat in violation of this section or in violation of any order issued under this section shall forfeit not less than $10 nor more than $50 for each offense. Each day a structure exists in violation of this section constitutes a separate offense.
Source: WI Statutes (Official Site)URL: https://docs.legis.wisconsin.gov/document/statutes/30.121Fetched: 10/7/2026