Leech Hollow Subwatershed Site C-11 Reservoir Report
Last Updated: December 15, 2025
Located in Monona, Iowa, the Leech Hollow Subwatershed Site C-11 is a dam with a primary purpose of fire protection, stock, or small fish pond.
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Summary
Built in 1978, this earth dam stands at a height of 40 feet and spans a length of 540 feet, with a storage capacity of 205 acre-feet. The drainage area for this dam is 0.68 square miles, with a surface area of 10.9 acres, making it a significant resource for flood risk reduction and recreation in the area.
Managed by the Iowa Department of Natural Resources, the dam is regulated, permitted, and inspected by the state to ensure its structural integrity and functionality. The hazard potential of the dam is rated as low, with a moderate risk assessment score. Despite not being rated for its condition assessment, the dam is closely monitored to mitigate any potential risks and ensure the safety of the surrounding community. With its strategic location along the TR-McClarey Creek, the Leech Hollow Subwatershed Site C-11 serves as a vital water resource for the region.
Overall, the Leech Hollow Subwatershed Site C-11 plays a crucial role in water management and conservation efforts in Monona, Iowa. With its multiple functions, including fire protection, stock, and small fish pond usage, as well as flood risk reduction and recreational opportunities, this dam serves as a valuable asset for the local government. Through ongoing inspections and regulatory oversight, the dam continues to provide essential services while maintaining a low hazard potential and moderate risk assessment score, showcasing its importance in sustainable water resource management and climate resilience efforts in the region.
Year Completed |
1978 |
Dam Length |
540 |
Dam Height |
40 |
River Or Stream |
TR-MC CLAREY CREEK |
Primary Dam Type |
Earth |
Surface Area |
10.9 |
Drainage Area |
0.68 |
Nid Storage |
205 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
40 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Maple River At Mapleton
|
323cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
West Fork Ditch At Hornick
|
80cfs |
Soldier River At Pisgah
|
112cfs |
Missouri River At Decatur
|
14900cfs |
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.
Leech Hollow Subwatershed Site C-11