Personal tools

Return to Top
DNRC Headquarters
1539 Eleventh Ave. Helena, MT 59601
Questions? Email us

Permitting Your Existing Dam



Tongue River Dam

General Information – Dam Safety Permits

Exempt from the Dam Safety Act are dams that are owned by the federal government, inspected by the Federal Energy Regulatory Commission, included in a mine operating permit issued by the Montana Department of Environmental Quality or associated with facilities certified under the Major Facility Siting Act. Non-federal dams on federal property with federal oversight are also exempt.

Downstream Hazard Classification ($125 fee)

To build a new dam or alter an existing dam with an impoundment capacity of 50 acre feet or more, you must apply to the DNRC Dam Safety Program for a hazard classification.

More information on Downstream Hazard Classification

Dams classified as high hazard, and containing over 50 acre foot of water, are required to obtain additional permits from the DNRC Dam Safety Program.

Construction Permits

If construction or repair is planned, a Construction Permit must be obtained.

Proposing to Build a New Dam

Proposing to Repair an Existing Dam

Operation Permits

Prior to storing water, an Operation Permit must be obtained. There are three components to getting an Operation Permit for a High Hazard dam:

1.    Five-Year Engineers Inspection

High Hazard Dams are required to have a formal comprehensive inspection at least once every five years.

2.     Operation and Maintenance Manual

 An Operation and Maintenance Manual is required to permit a High Hazard Dam.

3.     Emergency Action Plan

 All High Hazard Dams must have an Emergency Action Plan.

Statement of Owner's Intent

Before DNRC can issue an Operation Permit, the High Hazard Dam Owner must agree to follow the Engineer's recommendations and state a timeline to meet the recommendations. Several forms are available to assist dam owners with this task:

 Annual Operation Permit Requirements

Dam owners are required to complete an Annual Owner inspection.  This inspection is less formal than the five year inspection and can be done by the dam owner, their engineer, or the dam tender.

The Emergency Action Plan must be updated annually.