Rainbow Lake Dam Reservoir Report
Last Updated: December 19, 2025
Rainbow Lake Dam, located in Greene County, Missouri, is a state-owned structure primarily designed for flood risk reduction along the TR-Sims Branch of the North Dry Sac River.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1974, this earth dam stands at a height of 42 feet and has a length of 500 feet, providing a storage capacity of 240 acre-feet. With a normal storage level of 64 acre-feet, the dam serves multiple purposes including debris control, flood risk reduction, and recreation.
Despite its satisfactory condition assessment in 2013, Rainbow Lake Dam has a high hazard potential, making regular inspections and enforcement crucial for its safety and effectiveness. The dam is regulated by the Missouri Dam and Reservoir Safety Program and is subject to state permitting, inspection, and enforcement. With a moderate risk assessment rating, the dam's emergency action plan was last revised in 2013, ensuring that necessary measures are in place to manage any potential risks associated with the structure.
Water resource and climate enthusiasts can appreciate Rainbow Lake Dam for its role in mitigating flood risks and providing recreational opportunities while also recognizing the importance of ongoing maintenance and regulation to ensure its safety. The dam's location in Greene County, Missouri, highlights its significance in protecting the local community and surrounding areas from potential flooding events. As a state-owned structure with a history dating back to the 1970s, Rainbow Lake Dam continues to play a vital role in water resource management and climate resilience efforts in the region.
Year Completed |
1974 |
Dam Length |
500 |
Dam Height |
42 |
River Or Stream |
TR-SIMS BR N DRY SAC RIVER |
Primary Dam Type |
Earth |
Surface Area |
13 |
Drainage Area |
227 |
Nid Storage |
240 |
Structural Height |
42 |
Outlet Gates |
None |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
42 |
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.
Rainbow Lake Dam