Grassy Creek Watershed Dam G- 98 Reservoir Report
Last Updated: December 19, 2025
Grassy Creek Watershed Dam G-98, located in Lewis, Missouri, was completed in 1993 by the USDA NRCS and serves a primary purpose of flood risk reduction along the Grassy Creek.
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Summary
This earth dam stands at a height of 29 feet and has a hydraulic height of 28 feet, providing a maximum storage capacity of 143 acre-feet. With a normal storage capacity of 36 acre-feet and a drainage area of 145 square miles, this dam plays a crucial role in managing water flow and mitigating flood risks in the region.
Despite being classified as a low hazard potential structure, Grassy Creek Watershed Dam G-98 has a moderate risk assessment rating of 3. The dam features an uncontrolled spillway type with a width of 30 feet, designed to handle a maximum discharge of 223 cubic feet per second. Although the condition assessment is currently listed as "Not Rated," regular inspections are conducted to ensure the safety and functionality of the dam. While the dam does not have outlet gates or associated structures, it remains an essential part of the local government's flood risk reduction strategy in the area.
With its strategic location in the Grassy Creek watershed, Dam G-98 plays a vital role in protecting the surrounding area from potential flooding events. The dam's design, construction, and operation are overseen by the Natural Resources Conservation Service, contributing to the overall management of water resources in Missouri. As a key component in the region's flood risk reduction efforts, Grassy Creek Watershed Dam G-98 highlights the importance of proactive infrastructure to protect communities and wildlife habitats from the impacts of extreme weather events and changing climate patterns.
Year Completed |
1993 |
Dam Length |
485 |
Dam Height |
29 |
River Or Stream |
GRASSY CREEK |
Primary Dam Type |
Earth |
Surface Area |
5 |
Hydraulic Height |
28 |
Drainage Area |
145 |
Nid Storage |
143 |
Structural Height |
39 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
39 |
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- 98