Municipalities shall develop floodplain zoning maps, reflecting the best available data, which show the areas to be regulated. They shall also develop floodplain zoning ordinances to define proper uses in those regulated areas. These floodplain maps and zoning ordinances shall regulate all floodplains where serious flood damage may occur. The minimum limits for regulatory purposes shall be all those areas covered by water during the regional flood.
Wis. Admin. Code Department of Natural Resources NR 116.06