Grassy Creek Watershed Dam G- 77 Reservoir Report
Last Updated: December 19, 2025
Grassy Creek Watershed Dam G-77, located in Lewis, Missouri, was completed in 1996 by the Natural Resources Conservation Service and serves as a crucial flood risk reduction structure for the area.
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Summary
This earth dam stands at a height of 24 feet and has a structural height of 31 feet, with a length of 540 feet. With a normal storage capacity of 15 acre-feet and a maximum storage of 53 acre-feet, this dam plays a vital role in protecting the surrounding area from potential flooding events.
The dam, situated on Grassy Creek, has a low hazard potential and has not been rated for its condition assessment as of yet. Despite not being state-regulated or inspected, it meets guidelines for emergency action planning and has an uncontrolled spillway with a width of 20 feet. The risk assessment for this dam is moderate, indicating the need for continued monitoring and potential risk management measures to ensure its effectiveness in flood risk reduction. With a drainage area of 102.4 square miles, this dam plays a crucial role in protecting the local community from the impacts of extreme weather events.
While Grassy Creek Watershed Dam G-77 is not currently state-regulated or inspected, it remains a key structure for flood risk reduction in the area. With its low hazard potential and moderate risk assessment, this dam serves as a crucial line of defense against potential flooding events. Continual monitoring and potential risk management measures will be essential to ensuring the effectiveness of this earth dam in protecting the surrounding community and environment from the impacts of extreme weather events and climate change.
Year Completed |
1996 |
Dam Length |
540 |
Dam Height |
24 |
River Or Stream |
GRASSY CREEK |
Primary Dam Type |
Earth |
Surface Area |
3 |
Hydraulic Height |
24 |
Drainage Area |
102.4 |
Nid Storage |
53 |
Structural Height |
31 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
31 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South Fabius River Near Taylor
|
12cfs |
North River At Palmyra
|
15cfs |
Wyaconda River Above Canton
|
13cfs |
Bear Creek Near Marcelline
|
5cfs |
Bear Creek At Hannibal
|
2cfs |
Salt River Near Shelbina
|
16cfs |
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- 77