US Army Corps of Engineers
Omaha District

Post-Flood Permitting - MT

Published April 6, 2016

Under section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act

The U.S. Army Corps of Engineers understands that during a flood emergency and times of imminent danger landowners may decide to do what they determine is necessary to protect their property. Where possible, it is imperative for the public to contact the USACE Montana Regulatory Office (406) 441-1375 for work in waters of the U.S. associated with flood protection and repair work performed in waters of the U.S. for flood damaged areas within the State of Montana and the Omaha District. A flood emergency does not remove the landowner's responsibility to obtain permits under Sections 10 and 404 where permits are required.

Under Section 404 of the Clean Water Act, USACE regulates fill material placed below the Ordinary High Watermark (OHWM) within waters of the U.S. and may regulate the removal of fill material. The OHWM is the line on the shore/bank/waterway established by the fluctuations of water and indicated by physical characteristics. Waters of the U.S. include the area below the OHWM of stream channels and lakes or ponds connected to the tributary system, and wetlands adjacent to these waters. Isolated waters and wetlands, as well as man-made channels, may be waters of the U.S. in certain circumstances, which must be determined on a case-by-case basis. Under the authority of Section 10 of the Rivers and Harbors Act, Department of the Army permits are required for structures or work in, over, under or affecting navigable waters of the U.S.  Fill placed in upland areas (areas above the OHWM) is not typically regulated under the Clean Water Act. It is the landowner’s responsibility to contact USACE to determine if a flood-related activity lies within the Corps’ regulatory jurisdiction.

The District Engineer for the Omaha District  has developed a Regional General Permit 14-01 (MT-RGP-14-01), authorizing certain flood-related fill or excavation activities, other work associated with flood protection, and repair work for flood-damaged areas performed in waters of the U.S. within the State of Montana. 

Waters of the U.S. include, but are not limited to, rivers, lakes, ponds, creeks, gulches, coulees, wetland areas, and some ditches and canals. This Montana Regional General Permit (RGP) authorizes the following flood protection, reconstruction and repair work for flood damaged areas:

  1. An “emergency situation” is present where there is a clear, sudden, unexpected, and imminent threat to life or property demanding immediate action to prevent or mitigate loss of, or damage to, life, health, property or essential public services (i.e., a situation that could potentially result in an unacceptable hazard to life or a significant loss of property if corrective actions, including the repair, rehabilitation, or replacement of those structures or fills destroyed or damaged by the emergency, are not undertaken immediately).
  2. Discharges associated with excavation or dredging of sediment and debris, including storm deposited material, and the temporary or permanent discharge of fill associated with the excavation from waters of the U.S. where such an activity would prevent loss of property or where such activity is necessary to reduce flooding and/or erosion. This RGP DOES NOT authorize any channelization, channel widening, deepening, or straightening beyond channel limits that existed prior to the event, nor does it authorize the redeposit or disposal of dredged or excavated materials into waters of the U.S.
  3. The installation of structures in navigable waters and/or discharge of fill material into waters of the U.S. to facilitate the repair or replacement of collapsed roads or other structures or fills which failed or are failing as a result of the emergency (i.e. bank stabilization, bridges, utility lines, intakes, railroads, canals etc.).
  4. The temporary discharge of fill material into waters of the U.S. to facilitate the emergency work, provided no practicable upland areas are available.
  5. The installation and removal of cofferdams or diversion structures to temporarily isolate or dewater a work site.
  6. New bank stabilization must be less than 300 linear feet and average less than 1 cubic yard per running foot below the OHWM. 
  7. Temporary fills in waters of the U.S. are limited to 0.25 acre or less in size. Permanent fills are limited to 0.10 acre or less in size.
  8. Within 15 days of the start of the emergency work, or within 48 hours if the work occurs within the Blackfeet Indian Reservation, USACE must be notified. Any additional authorizations or special conditions may be included at that time.
  9. Work must commence within 30 days from the date of the emergency or this permit does not apply.

Proposed wetland fill or drainage activities authorized by this permit may require mitigation.  Mitigation plans will be developed by the applicant, approved by the Corps, and coordinated with the applicable resource agencies on a case-by-case basis.  In urgent situations, approval of mitigation plans by the Corps may be subsequent to the approval of the requested work, since sufficient time may not be available to approve mitigation before the work must take place.

To request authorization of work under MT-RGP 14-01, contact the Montana Regulatory office for a determination that the proposed work is necessitated by emergency conditions and meets the MT-RGP-14-01 criteria.  Note the Notification requirement in h. above, and see the “Application Procedures,” below, which are also found in MT-RGP-14-01.


Within 15 days after the start of any activities authorized under this RGP, or 48 hours, if work will occur within the Blackfeet Indian Reservation, the permittee is required to contact in writing by mail or fax:

HELENA, MT  59626-9705
PHONE: (406) 441 - 1375 (FAX) 441 -1380

The following written information is required:

1. Name, address, and telephone number of the landowner and of the person responsible for the work (if other than the landowner).

2. A written description of the work, including the purpose and need; type, composition and volume of fill and/or excavated material; length, width and depth of fill material and/or excavation area; disposal site for the fill and/or excavated material; borrow site for fill material; types of equipment to be used; and impacts to wetlands, streams or other waters of the U.S. 

3. Description of the emergency and the potential for loss of life or property.

5. Purpose of the activity.

6. A written legal description of the project location including section, township, range, and county, as well as latitude and longitude if known.

7. Names, addresses, and telephone numbers of adjacent property owners.

8. A set of drawings on 8 1/2 by 11 inch paper, with dimensions of the proposed work, showing:

  1. The project location identified on an aerial photograph or map, including any disposal site locations.
  2. A plan or top view of the project area.
  3. A typical cross-section or side view of the project.
  4. Photographs of the project area.
  5. As applicable, a restoration plan showing how all temporary fills and structures will be removed and the area restored to pre-project conditions.

9. The Corps will inform the permittee if further authorizations or special conditions are required.

If you have questions or would like assistance in determining if a permit is required for any flood-related activities, please contact the appropriate USACE Regulatory Office from the list of contacts below. 


  • Montana Regulatory State Program Office (406) 441-1375
  • Omaha District, Regulatory Branch (402) 995-2451