West Fork Big Creek Dam B-109 Reservoir Report
Last Updated: December 16, 2025
West Fork Big Creek Dam B-109, located in Harrison, Missouri, is a vital structure designed by the USDA NRCS in 1991 for the primary purpose of flood risk reduction along the West Fork Big Creek.
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Summary
This Earth-type dam stands at 26.5 feet high and stretches 390 feet in length, with a maximum storage capacity of 50 acre-feet and a normal storage of 12 acre-feet. Despite its relatively low hazard potential and moderate risk assessment, the dam has not been state-regulated or inspected, highlighting the importance of ongoing monitoring and maintenance efforts by the local government.
With a surface area of 6 acres and a drainage area of 240 square miles, West Fork Big Creek Dam B-109 plays a crucial role in protecting the surrounding area from potential flood events. The dam features an uncontrolled spillway with a width of 30 feet, allowing for the safe release of excess water during periods of high discharge. While the dam currently holds a "Not Rated" condition assessment, it is essential for stakeholders and water resource enthusiasts to advocate for regular inspections, emergency action plans, and risk management measures to ensure the continued safety and effectiveness of this important infrastructure.
As part of the Rock Island District and under the ownership of the local government in Bethany, West Fork Big Creek Dam B-109 serves as a key component in the region's flood control system. While the dam has not undergone recent inspections or assessments, its strategic location and design contribute to its overall moderate risk assessment. With a focus on maintaining and enhancing the dam's functionality, stakeholders can work together to ensure the long-term resilience and sustainability of this critical water resource infrastructure in the face of changing climate conditions.
Year Completed |
1991 |
Dam Length |
390 |
Dam Height |
26.5 |
River Or Stream |
TR-WEST FORK BIG CREEK |
Primary Dam Type |
Earth |
Surface Area |
6 |
Hydraulic Height |
26 |
Drainage Area |
240 |
Nid Storage |
50 |
Structural Height |
28 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
28 |
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.
West Fork Big Creek Dam B-109