Minn. Stat. § 344.10

If lands of different persons must be fenced and are bounded upon or divided by a stream or pond which, in the judgment of the fence viewers, is not in itself a sufficient fence, and if the viewers determine that it is impracticable, without unreasonable expense, for a partition fence to be made on the waters at the true boundary line, and if the occupant on either side fails to join with the occupant on the other side in making a partition fence on one side or the other, then the fence viewers, on application of either party, shall view the stream or pond, and, after giving due notice to the parties, determine, in writing, on which side of the stream or pond the fence must be erected and maintained, or whether partly on one side and partly on the other. If either party fails to build or maintain the assigned part of the fence according to the viewers' determination, the other party may build and maintain the fence, and the delinquent party must pay the charges and costs provided for in other cases in this chapter.