Rowden Lake Dam Reservoir Report
Nearby: Gotter Pond Dam Kahl Bros. Pond Dam 1
Last Updated: December 23, 2025
Rowden Lake Dam, located in Alton, Illinois, is a privately owned structure designed by the USDA NRCS with a primary purpose of recreation.
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Summary
Completed in 1971, this earth dam stands at a height of 40 feet and stretches 380 feet in length, providing a storage capacity of 160 acre-feet. The dam is managed by the Illinois Department of Natural Resources and falls under state jurisdiction for regulation and inspection.
Despite its low hazard potential, Rowden Lake Dam is considered to have a moderate risk level, with an inspection frequency of 5 years. While the condition assessment is not available, the dam's emergency action plan status, risk assessment, and risk management measures are yet to be determined. The dam's spillway is uncontrolled, with an outlet gate that is similarly uncontrolled, posing a potential challenge in the event of a flood or emergency situation.
Overall, Rowden Lake Dam serves as a recreational resource in Jersey County, Illinois, along Piasa Creek. It is a significant part of the local landscape and provides both aesthetic appeal and functional benefits. However, ongoing monitoring and maintenance are essential to ensure the safety and longevity of this important water resource structure.
Year Completed |
1971 |
Dam Length |
380 |
Dam Height |
40 |
River Or Stream |
PIASA CREEK-OFFSTREAM |
Primary Dam Type |
Earth |
Nid Storage |
160 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
40 |
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.
Rowden Lake Dam