Grade Lake Dam Reservoir Report
Nearby: Pleasant Dam East Lake Dam
Last Updated: December 9, 2025
Grade Lake Dam, located in Osceola, Iowa, is a vital water resource structure designed by CB&Q RR and Ray Henley in 1900.
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Summary
With a height of 44 feet and a length of 1300 feet, this earth dam serves the primary purpose of recreation, offering a surface area of 25.7 acres for leisure activities. The dam's reservoir provides a normal storage capacity of 217 acre-feet and a maximum storage of 865 acre-feet, making it a significant water source in the region.
Managed by the Iowa Department of Natural Resources, Grade Lake Dam is regulated, inspected, and enforced by state authorities to ensure its safety and functionality. The dam's spillway type is uncontrolled, with a width of 4 feet, while its hazard potential is classified as high, signaling the need for regular monitoring and risk management measures. Despite its moderate risk assessment, the dam's condition is deemed satisfactory as of the last inspection in May 2019, highlighting its importance in water resource management and climate resilience efforts in the area.
Water resource and climate enthusiasts can appreciate Grade Lake Dam as a key infrastructure supporting recreational activities and water storage in Clarke County, Iowa. As a state-regulated dam with a significant storage capacity and high hazard potential, its management and maintenance play a crucial role in ensuring public safety and environmental sustainability. With a rich history dating back to the early 20th century, Grade Lake Dam stands as a symbol of resilience and innovation in water resource engineering, serving as a valuable asset in the region's efforts to adapt to changing climate conditions and enhance water security.
Year Completed |
1900 |
Dam Length |
1300 |
Dam Height |
44 |
River Or Stream |
TR-WHITEBREAST CREEK |
Primary Dam Type |
Earth |
Surface Area |
25.7 |
Drainage Area |
0.61 |
Nid Storage |
865 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
44 |
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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Buck Stop Camp
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Bottom Oak Camp
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White Oak Camp
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Longbeard Camp
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Black Oak Camp
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Grade Lake Dam