Prior Lake Dam Reservoir Report
Last Updated: December 18, 2025
The Prior Lake Dam, located in Marthasville, Missouri, was completed in 1971 and serves as a recreational water resource along the TR-Charrette Creek.
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Summary
This private-owned Earth dam stands at a height of 34 feet and has a storage capacity of 91 acre-feet. With a surface area of 5 acres and a drainage area of 12 square miles, the dam provides a picturesque setting for outdoor enthusiasts and nature lovers to enjoy.
Despite its primary purpose for recreation, the Prior Lake Dam has a high hazard potential and is currently rated as "Not Rated" in terms of condition assessment. The dam is not regulated or inspected by the state, highlighting the importance of ongoing monitoring and maintenance to ensure its safety and integrity. As part of the St. Louis District, the dam plays a crucial role in water management and conservation efforts in the region.
For water resource and climate enthusiasts, the Prior Lake Dam offers a unique opportunity to appreciate the intersection of human infrastructure and natural landscapes. As a vital component of the local ecosystem, it is essential to prioritize the safety and maintenance of this dam to preserve its recreational and environmental benefits for future generations.
Year Completed |
1971 |
Dam Height |
34 |
River Or Stream |
TR-CHARRETTE CREEK |
Primary Dam Type |
Earth |
Surface Area |
5 |
Drainage Area |
12 |
Nid Storage |
91 |
Structural Height |
34 |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
34 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Cuivre River Near Troy
|
33cfs |
Dardenne Creek At Ofallon
|
6cfs |
Missouri River At Hermann
|
29400cfs |
Dardenne Creek At Old Town St. Peters
|
11cfs |
Bourbeuse River At Union
|
73cfs |
Bonhomme Creek Near Ellisville
|
0cfs |
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.
Prior Lake Dam