Post-Flood Permitting - WY

Post-Flood Permitting - WY

USACE Corps of Engineers, Omaha
Published June 23, 2022

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 Corps’ Wyoming Regulatory Office (307) 772-2300 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 Wyoming and the Omaha District. A flood emergency does not remove the landowner's responsibility to obtain a Section 404 permit if a permit is required. 

Under Section 404 of the Clean Water Act, the Corps 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. 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 the USACE to determine if a flood-related activity lies within the USACE Regulatory jurisdiction.

Waters of the U.S. include, but are not limited to, rivers, lakes, ponds, creeks, gulches and wetland areas. Prior to, during, and after an emergency flood situation, there are a number of actions that can be taken that usually do not require a permit under Section 404 of the Clean Water Act, such as:

  • Maintenance of structures (e.g., dikes, dams, levees, bridges, riprap) provided the maintenance does not modify the original character, scope, or size of the structure.
  • Maintenance of farm roads, forest roads and temporary mining roads provided specified best management practices are applied (contact the Wyoming Regulatory Office for best management practices).
  • Maintenance of farm or stock ponds, irrigation ditches, and drainage ditches. Also discharges associated with siphons, pumps, headgates, wingwalls, weirs, diversion structures, and other such facilities related to irrigation ditches.
  • Repair or replacement of uplands above the ordinary high water mark.

During a flood emergency, USACE will focus resources on the immediate needs of landowners. If a permit is required, the work can usually be authorized by one of the following Nationwide Permits (NWP). Upon receipt of a project description and location map, the Corps can typically provide a response within 1-3 days during an emergency situation.

For regulated activities that cannot be authorized by a NWP, there are expedited permitting procedures that can be used during an emergency situation. Typically upon receipt of a location map and description of proposed activities, USACE can provide a response within 4-5 days for these activities during an emergency situation.  

  • NWP 3: maintenance (Allows for minor deviations to the pre-flood fill area or structure configuration)
  • NWP 12: oil or natural gas pipeline activities
  • NWP 13: bank stabilization
  • NWP 14: linear transportation projects
  • NWP 18: minor discharges (25 CY or less)
  • NWP 31: maintenance of existing flood control facilities
  • NWP 33: temporary construction, access,  and dewatering
  • NWP 37: emergency watershed protection and rehabilitation
  • NWP 45: repair of uplands damaged by discrete events
  • NWP 57: electric utility line & telecommunications activities
  • NWP 58: utility line activities for water and other substances

EMERGENCY AUTHORIZATION PROCEDURES: More extensive flood repair work which exceeds the (NWP) limits may be authorized under emergency authorization procedures when there is an unacceptable hazard to life, significant loss of property and/or an immediate, unforeseen, and significant economic hardship if corrective action requiring a permit is not undertaken within a time period less than the normal time needed to process an application under standard procedures.

The following are the procedures to process a request for an emergency authorization:

  1. Project proponents should e-mail or personally deliver to the Wyoming Regulatory Field Office information which details the proposed work, location map and a narrative description of what needs to be done, how soon, and how the situation occurred. 
  2. The Wyoming Regulatory Office will coordinate the emergency response with the Omaha District Regulatory Office, Northwestern Division Office, and other resources agencies. 

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.


  • Wyoming Regulatory State Field Office (307) 772-2300
  • Omaha District, Regulatory Branch (402) 995-2451