Little River Watershed Site 65 Reservoir Report
Last Updated: December 10, 2025
Little River Watershed Site 65, located in Decatur, Iowa, is a significant earth dam completed in 1987 for flood risk reduction along the West Little River.
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Summary
With a height of 45 feet and a length of 1470 feet, this dam has a storage capacity of 6700 acre-feet and serves a drainage area of 9.4 square miles. Managed by the Iowa Department of Natural Resources, this dam is regulated, inspected, and enforced by state authorities to ensure its structural integrity and safety.
The dam at Little River Watershed Site 65 plays a crucial role in mitigating flood risks in the region, while also providing recreational opportunities for the local community. The dam's spillway type is uncontrolled with a width of 3 feet, and its hazard potential is deemed significant. Despite this, the condition assessment in 2019 reported the dam as satisfactory, with a moderate risk rating. Regular inspections are conducted every 5 years to monitor its performance and address any potential issues that may arise.
As a key infrastructure for water resource management, Little River Watershed Site 65 is a vital component of the local ecosystem and serves as a protective barrier against flooding events. With its strategic location and design, this dam showcases the collaborative efforts of various agencies, including the Natural Resources Conservation Service, in ensuring the safety and functionality of the structure. For water resource and climate enthusiasts, this site offers a fascinating case study in flood risk reduction and the importance of sustainable water management practices in the face of changing environmental conditions.
Year Completed |
1987 |
Dam Length |
1470 |
Dam Height |
45 |
River Or Stream |
WEST LITTLE RIVER |
Primary Dam Type |
Earth |
Surface Area |
144 |
Drainage Area |
9.4 |
Nid Storage |
6700 |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
45 |
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.
Little River Watershed Site 65
Shewmaker County Park
Slip Bluff County Park
Sand Creek State Wildlife Area
Nine Eagles State Park