Croy Subwatershed Site G3-2730 Reservoir Report
Last Updated: December 13, 2025
Located in Monona, Iowa, the Croy Subwatershed Site G3-2730 is a local government-owned dam designed by USDA NRCS, serving multiple purposes including fire protection, stock, and small fish pond management, as well as flood risk reduction.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1951, this earth dam stands at a height of 30 feet and has a storage capacity of 17 acre-feet. Situated along the TR- Maple River, this site has a low hazard potential and a moderate risk assessment rating.
Managed by the Iowa DNR, the Croy Subwatershed Site G3-2730 is state-regulated with permitting, inspection, and enforcement mechanisms in place. The dam's primary function is to protect the surrounding area from potential flooding events while also providing water storage for various agricultural and recreational purposes. With a surface area of 1 acre and a drainage area of 0.18 square miles, this dam plays a crucial role in water resource management in the region.
While the condition of the dam is currently not rated, efforts are being made to ensure its structural integrity and safety. With its strategic location and multiple benefits for the community, the Croy Subwatershed Site G3-2730 serves as a valuable asset in the sustainable management of water resources and climate resilience in Monona, Iowa.
Year Completed |
1951 |
Dam Height |
30 |
River Or Stream |
TR- MAPLE RIVER |
Primary Dam Type |
Earth |
Surface Area |
1 |
Drainage Area |
0.18 |
Nid Storage |
17 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Maple River At Mapleton
|
323cfs |
Soldier River At Pisgah
|
112cfs |
West Fork Ditch At Hornick
|
80cfs |
Missouri River At Decatur
|
15500cfs |
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.
Croy Subwatershed Site G3-2730