Patterson Creek No.20 Reservoir Report
Last Updated: December 5, 2025
Located in Mineral County, West Virginia, Patterson Creek No.20, also known as Liller Run, is a locally owned earth dam designed by the USDA NRCS in 1967 for flood risk reduction along the Liller Run stream.
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Summary
Standing at a height of 61 feet with a hydraulic height of 52 feet, this dam has a storage capacity of 457 acre-feet and serves a drainage area of 1.56 square miles. Despite its uncontrolled spillway type and high hazard potential, the dam's condition assessment in 2014 deemed it satisfactory, with a moderate risk rating.
Managed by the state regulatory agency DWWM, Patterson Creek No.20 is subject to regular state inspections and enforcement measures to ensure its functionality and safety. With a primary purpose of flood risk reduction, this dam plays a crucial role in protecting the surrounding area from potential inundation during heavy rainfall events. While it lacks associated structures and a controlled spillway, the dam's design and construction by the Natural Resources Conservation Service highlight a commitment to effective water resource management.
As water resource and climate change enthusiasts explore the intricacies of dam infrastructure, Patterson Creek No.20 stands as a notable example of local government efforts to mitigate flood risks in the region. With its rock and soil foundation, the dam's 400-foot length and 5-acre surface area contribute to its ability to store and regulate water flow along Liller Run. As stakeholders continue to monitor and maintain this vital piece of water infrastructure, its role in safeguarding the community from potential flooding remains paramount in the face of changing environmental conditions.
Year Completed |
1967 |
Dam Length |
400 |
Dam Height |
61 |
River Or Stream |
LILLER RUN |
Primary Dam Type |
Earth |
Surface Area |
5 |
Hydraulic Height |
52 |
Drainage Area |
1.56 |
Nid Storage |
457 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
61 |
Seasonal Comparison
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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.
Patterson Creek No.20
Bloomington Lake Near Elk Garden