Grindstone-Lost-Muddy Watershed Dam A- 11 Reservoir Report
Last Updated: December 5, 2025
Grindstone-Lost-Muddy Watershed Dam A- 11, located in DeKalb County, Missouri, serves as a vital structure for flood risk reduction along the Grand River.
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Summary
Constructed in 1992 by the USDA NRCS, this earth dam stands at a height of 32 feet and has a maximum storage capacity of 661 acre-feet. With a primary purpose of flood risk reduction, the dam plays a crucial role in protecting the surrounding area from potential inundation during periods of high water flow.
The dam's design features a stone core and soil foundation, with an uncontrolled spillway width of 81 feet. Despite being assessed as low hazard potential and not yet rated for condition, the dam is closely monitored for any necessary maintenance or improvements. The surrounding environment benefits from the dam's presence, with a drainage area of 150 square miles and a normal storage capacity of 111 acre-feet. While the risk assessment indicates moderate risk, the dam remains a key component in managing water resources and climate-related challenges in the region.
Overall, Grindstone-Lost-Muddy Watershed Dam A- 11 stands as a testament to the collaborative efforts of local government and the USDA NRCS in safeguarding the community against potential flood events. Its strategic location and design elements contribute to a comprehensive flood risk reduction strategy, ensuring the protection of lives and property along the Grand River. As water resource and climate enthusiasts, the dam serves as a focal point for understanding the intersection of infrastructure, natural resources, and environmental stewardship in managing water-related challenges.
Year Completed |
1992 |
Dam Length |
830 |
Dam Height |
32 |
River Or Stream |
GRAND RIVER |
Primary Dam Type |
Earth |
Surface Area |
3 |
Hydraulic Height |
28 |
Drainage Area |
150 |
Nid Storage |
661 |
Structural Height |
39 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
39 |
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.
Grindstone-Lost-Muddy Watershed Dam A- 11