John Meginess Reservoir Report
Nearby: Isabel Bill Lindskou
Last Updated: December 13, 2025
John Meginess is a privately owned dam located in Dewey, South Dakota, with a low hazard potential.
°F
°F
mph
Wind
%
Humidity
Summary
Constructed in 1949, this earth-type dam stands at 25 feet high and spans 330 feet in length, providing a maximum storage capacity of 60 acre-feet. The dam is regulated by the South Dakota Department of Environment and Natural Resources (DENR), with state permitting, inspection, and enforcement in place to ensure its safety and compliance with regulations. With a normal storage capacity of 60 acre-feet and a maximum discharge of 2440 cubic feet per second, John Meginess plays a crucial role in managing water resources in the area.
Situated on the TR GRAND river, John Meginess is overseen by the St. Paul District of the US Army Corps of Engineers and falls under the jurisdiction of South Dakota state agencies. Despite not being rated for condition assessment, the dam has not been modified over the years and poses a low risk to the surrounding area. While emergency action plans and inundation maps are not currently prepared for this structure, its role in water resource management and flood control highlights the importance of ongoing monitoring and maintenance. With a designated emergency contact and potential risk management measures, John Meginess stands as a key infrastructure element in the region's water resource and climate resilience efforts.
Year Completed |
1949 |
Dam Length |
330 |
Dam Height |
25 |
River Or Stream |
TR GRAND |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Nid Storage |
60 |
Hazard Potential |
Low |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Moreau R Near Whitehorse Sd
|
35cfs |
Grand R At Little Eagle Sd
|
47cfs |
Moreau R Near Faith Sd
|
14cfs |
Cedar Creek Nr Raleigh
|
20cfs |
Oak Cr Near Wakpala Sd
|
10cfs |
Cannonball River Nr Raleigh
|
40cfs |
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.
John Meginess