Lake Zahl Dam Reservoir Report
Nearby: Blacktail Dam Nelson Dam; Selmar
Last Updated: December 13, 2025
Lake Zahl Dam, located in Williams County, North Dakota, was completed in 1937 and is owned by the US Fish and Wildlife Service.
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Summary
This earth dam, standing at 9 feet high and 900 feet long, serves as a fish and wildlife pond with a storage capacity of 9,720 acre-feet. The dam, situated on the Pat's Coulee River, has a spillway width of 419 feet and features a single vertical lift outlet gate.
With a low hazard potential and a moderate risk assessment rating, Lake Zahl Dam is regulated by the North Dakota State Water Commission. The dam is inspected, permitted, and enforced by the state agency, ensuring its structural integrity and safety. Although its condition is not rated, the dam meets state regulatory requirements and serves as an essential resource for wildlife and water management in the region.
Enthusiasts of water resources and climate will appreciate Lake Zahl Dam for its role in providing habitat for fish and wildlife, as well as its contribution to water storage and management. As a federally-owned structure, the dam is a key feature in the conservation efforts of the US Fish and Wildlife Service and plays a vital role in maintaining the ecological balance of the area. Its location in the heart of North Dakota's natural landscape makes Lake Zahl Dam a noteworthy site for those interested in sustainable water resource management and environmental conservation.
Year Completed |
1937 |
Dam Length |
900 |
Dam Height |
9 |
River Or Stream |
PATS COULEE |
Primary Dam Type |
Earth |
Surface Area |
1300 |
Drainage Area |
52.5 |
Nid Storage |
9720 |
Outlet Gates |
Vertical Lift - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
9 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Lake Zahl Dam