Grassy Creek Watershed Dam G- 46 Reservoir Report
Last Updated: December 5, 2025
Grassy Creek Watershed Dam G-46, located in Lewis, Missouri, serves as a vital flood risk reduction infrastructure along the Little Grassy River.
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Summary
Built in 1991 by the USDA NRCS, this earth dam stands at a height of 24.8 feet, with a hydraulic height of 24 feet and a structural height of 28 feet. With a storage capacity of 87 acre-feet and a drainage area of 102.4 square miles, the dam plays a crucial role in protecting the surrounding area from potential flooding events.
Although categorized with a low hazard potential, Grassy Creek Watershed Dam G-46 is essential for maintaining the safety and resilience of the community. The dam's primary purpose is flood risk reduction, with additional benefits including fire protection, stock or small fish pond, and fish and wildlife pond. Despite its significant contributions, the dam's condition assessment remains unrated, emphasizing the need for regular inspections and maintenance to ensure its continued effectiveness in mitigating flood risks.
Managed by local government authorities, this dam stands as a testament to collaborative efforts in water resource management. The presence of an uncontrolled spillway and the absence of outlet gates highlight the simplicity of its design. With a moderate risk assessment rating of 3, it is important for stakeholders to remain vigilant in implementing risk management measures to safeguard the dam's integrity and the community's well-being in the face of potential climate challenges.
Year Completed |
1991 |
Dam Length |
480 |
Dam Height |
24.8 |
River Or Stream |
LITTLE GRASSY |
Primary Dam Type |
Earth |
Surface Area |
3 |
Hydraulic Height |
24 |
Drainage Area |
102.4 |
Nid Storage |
87 |
Structural Height |
28 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
28 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South Fabius River Near Taylor
|
12cfs |
Wyaconda River Above Canton
|
13cfs |
North River At Palmyra
|
21cfs |
Salt River Near Shelbina
|
30cfs |
Salt River At Hagers Grove
|
1cfs |
Bear Creek Near Marcelline
|
5cfs |
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.
Grassy Creek Watershed Dam G- 46