Hannon Lake Dam Reservoir Report
Nearby: Dugan Dam Thurman Lake Dam
Last Updated: December 20, 2025
Hannon Lake Dam, located in Dallas County, Missouri, is a privately owned structure primarily used for irrigation purposes.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1975, this earth dam stands at a height of 15 feet and has a storage capacity of 80 acre-feet. While the dam also serves recreational purposes, it is not regulated by the state and has a low hazard potential. Despite its age, the dam's condition has not been rated, and there is no recent inspection data available.
Situated on Patterson Branch, a tributary of the Little Rock District, Hannon Lake Dam covers a surface area of 10 acres and drains an area of 85 square miles. The dam's primary purpose is to provide water for irrigation, with a normal storage level of 43 acre-feet. Although the dam lacks a spillway and outlet gates, its low hazard potential suggests minimal risk of failure. While the dam has not been inspected recently, its emergency action plan status and compliance with guidelines remain unknown.
Overall, Hannon Lake Dam presents an interesting case study for water resource and climate enthusiasts, showcasing a privately owned structure that has provided essential irrigation water for over four decades. The dam's location in a rural area highlights the importance of proper maintenance and inspection protocols to ensure the safety of surrounding communities. Further research and monitoring may be needed to assess the dam's long-term viability and resilience in the face of changing climate patterns and water resource demands.
Year Completed |
1975 |
Dam Height |
15 |
River Or Stream |
PATTERSON BRANCH |
Primary Dam Type |
Earth |
Surface Area |
10 |
Drainage Area |
85 |
Nid Storage |
80 |
Structural Height |
15 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
15 |
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.
Hannon Lake Dam