Leech Hollow Subwatershed Site C-6 Reservoir Report
Last Updated: December 14, 2025
Leech Hollow Subwatershed Site C-6 is a local government-owned dam located in Monona, Iowa, specifically in the city of Castana.
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Summary
Completed in 1970, this earth dam stands at a height of 40 feet and spans a length of 480 feet, with a storage capacity of 180 acre-feet. Its primary purposes include fire protection, stock, and small fish pond, as well as flood risk reduction and recreation. The dam is regulated by the Iowa Department of Natural Resources, with state permitting, inspection, and enforcement in place to ensure its safety and compliance.
Situated on TR-McClarey Creek, Leech Hollow Site C-6 has a low hazard potential and a moderate risk assessment rating. Despite not having a current condition assessment, the dam's risk management measures and emergency action plan status are not reported. The dam's location and design by Shive Hattery and Associates and USDA SCS, together with its state jurisdiction and regulatory oversight, highlight its significance for water resource management and climate resilience in the region. With its unique features and purpose, Leech Hollow Subwatershed Site C-6 serves as a valuable asset for fire protection, water storage, and recreational activities in the area.
Year Completed |
1970 |
Dam Length |
480 |
Dam Height |
40 |
River Or Stream |
TR-MC CLAREY CREEK |
Primary Dam Type |
Earth |
Surface Area |
7.9 |
Drainage Area |
1.34 |
Nid Storage |
180 |
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-6