This permit is required for anyone planning new construction within a designated 100-year floodplain. Check with your local planning office to determine whether a 100-year floodplain has been designated for the stream of interest. Projects that have the potential to alter the mapped 100-year flood elevation may require extensive hydraulic analysis and permit review.
Contact: Your Local Floodplain Administrator
Or: Montana Department of Natural Resources and Conservation
Water Resources Division
P.O. Box 201601
Helena, Montana 59620-1601
Phone: (406) 444-6654, or (406) 444-6610