Probable Maximum Precipitation Study and Interim Guidance

In June 2021, the DWR completed an update of statewide Probable Maximum Precipitation (PMP) data through a two-year study conducted by Applied Weather Associates (AWA). Additionally, the DWR continues to develop updated dam design guidelines for North Dakota. While these guidelines are still in development, the selection and usage of PMP values in the design of dams will be governed by interim guidance.

Regulatory Program: Dam Safety

The purpose of North Dakota’s Dam Safety Program is to minimize the risk to life and property associated with the potential failure of dams in the state. Functions of the Dam Safety Program include reviewing construction permit applications for dams, conducting dam inspections, maintaining an inventory of dams in North Dakota, determining the hazard classification of dams, and assisting with emergency preparedness activities.


Construction Permits

The dam safety program reviews construction permit applications for dams, holding ponds, and lagoons, as required under NDCC 61-16.1-38. More information on construction permits can be found on the Construction Permits page.


Inspections

A primary function of the Dam Safety Program is to conduct dam inspections and provide recommendations to dam owners regarding necessary maintenance and repairs. Dam Safety Program staff inspects non-federally owned high hazard and medium hazard dams on a rotational basis. Additional inspections are conducted following the spring runoff, on request from dam owners, or when there are concerns at a dam, such as during flood events.

Dam maintenance and repairs are the responsibility of the dam owner. Funding to assist with dam safety repairs may be available through the DWR cost-share program, or through other funding sources.


Emergency Action Plans

Emergency Action Plans (EAPs) are required for all high hazard and medium hazard dams under NDCC 61-03-25. An EAP is a formal document that identifies potential emergency situations that could occur at a dam and specifies the course of action to be taken when an emergency situation arises. The purpose of an EAP is to minimize loss of life and property damage.

Dam owners are responsible for developing, testing, and updating an EAP for their dam. The DWR has developed an EAP guidance document to provide additional guidance for developing, testing, and updating EAPs in order to comply with NDCC 61-03-25. A recommended EAP template, developed by the Natural Resources Conservation Service is also available. Additional general guidance on developing an EAP is available in the document “Federal Guidelines for Dam Safety - Emergency Action Planning for Dams” (link below). Funding to assist with developing an EAP may be available through the Cost-Share Program.

North Dakota Emergency Action Plan Guidelines For Dams

Federal Guidelines For Dam Safety - Emergency Action Planning For Dams


Dam Inventory

The Dam Safety Program maintains an inventory of dams in North Dakota. North Dakota’s inventory of dams can be found on the Maps/GIS data page.


Hazard Classifications

Dams in North Dakota are classified as low hazard, medium hazard, or high hazard based on the potential for loss of life or property damage downstream if the dam were to fail. These classifications are defined in NDAC 89-08-01-01. The hazard classification is determined when an applicant applies for a construction permit for a dam. The hazard classification of a dam can also change over time due to changes in development downstream of the dam.

Hazard Classification and Legacy Dams Policy/Guidelines


Low Head Dams

Low head dams are usually simple concrete or rock masonry structures that span the width of the river or stream, raising the water level behind them until it reaches a height sufficient to flow over the dam. These low head dams can create dangerous conditions that recreational river users may not be aware of or may underestimate. Under the right conditions, water flowing over the dam can cause a “roller effect” on the downstream side of the dam. Strong recirculating currents can trap and drown boaters, swimmers, or other water users. More information regarding safety at dams is available at the Association of State Dam Safety Officials.

Over, Under, Gone: The Killer in Our Rivers (Video Link)

Hazards of Low Head Dams (Video Link)

Map Of North Dakota’s Low Head Dams

Low Head Dam Sign

Because low head dams are known to be dangerous, the DWR is providing free cautionary safety signs to the owners of these dams that may be in your area. DWR will provide multiple signs per dam, free of charge. However, installation efforts will be a local responsibility. For more information on these free dam safety signs, please call (701) 328-4953 or e-mail.


Program Rules

North Dakota Administrative Code - Link to Article 89-08 "Dams, Dikes, and Other Devices"

North Dakota Century Code - Link to Title 61 "Waters"


Guidance for Dam Owners and Designers

Dam Owner Workshop Video, January 2023 (Maintenance and Operations)

Dam Owner Workshop Video, June 2022 (Basics of Owning a Dam)

Dam Ownership Fact Sheets (ASDSO)

Dam Owner Academy Videos (ASDSO)

Dam Owner Emergency Intervention Toolbox

Technical Manual for Dam Owners – Impacts of Plants on Earthen Dams (FEMA 534)

Technical Manual for Dam Owners – Impacts of Animals on Earthen Dams (FEMA 473)

Federal Guidelines for Dam Safety – Glossary of Terms (FEMA)

Technical Manual: Conduits through Embankment Dams (FEMA)

Filters for Embankment Dams – Best Practices for Design and Construction (FEMA)

Technical Manual: Outlet Works Energy Dissipators (FEMA)

Living With Dams: Know Your Risks

Living With Dams: Extreme Rainfall Events

Association of State Dam Safety Officials

Western Dam Engineering Technical Notes


Information

For more information on Dam Safety, please contact Karen Goff, Dam Safety Program Manager at (701) 328-4953 or e-mail.