Wisconsin Statutes Fences (Ch. 90) § 90.09. Partition when land bounded by water

(1) When the boundary line between enclosed lands owned by different persons is a river, brook, pond or creek, which of itself is not a sufficient fence, and it is impracticable, without unreasonable expense, for a partition fence to be built on the true boundary line, and either owner or occupant refuses to join in making a partition fence on either side of the river, brook, pond or creek, or they disagree respecting making a partition fence, either party may apply to 2 or more fence viewers of the town, who, after giving notice as provided in s. 90.07, shall proceed to view the river, brook, pond or creek.

(2) If the fence viewers determine that the river, brook, pond or creek is not a sufficient fence and that it is impracticable, without unreasonable expense, to build a fence on the true boundary line, the fence viewers shall, in writing under their hands, determine how or on which side of the river, brook, pond or creek the fence shall be built or whether the fence shall be built partly on one side and partly on the other side. The fence viewers shall assign to each owner or occupant that owner's or occupant's share of the fence and the time within which the respective parties shall build the fence. The fence viewers shall file their determination in the office of the town clerk, who shall record the determination.

(3) If either party refuses or neglects to build that party's part of the fence within the time assigned by the fence viewers, the other party may, after having completed his or her own part, build the other party's part and recover the expense of building the other party's part of the fence as provided under s. 90.11.

(4) If the fence viewers determine that it is impracticable, either from the formation of the banks of the river, brook, pond or creek or for any other reason, to maintain any fence along or near the boundary line, they shall give written notice to the parties of that determination.