Iroquois Lake Dam Reservoir Report

Last Updated: December 5, 2025

Iroquois Lake Dam, located in Gates Mills, Ohio, is a private dam primarily used for recreation purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam was completed in 1960 and stands at a height of 17 feet with a length of 1500 feet. It impounds an unnamed tributary to the Chagrin River, providing a surface area of 12.8 acres and a drainage area of 0.06 square miles.

Owned privately, Iroquois Lake Dam is regulated by the Department of Natural Resources in Ohio, ensuring that it meets state inspection and enforcement standards. The dam has a storage capacity of 111.5 acre-feet, with a normal storage level of 52.1 acre-feet. Its hazard potential is considered significant, although its condition assessment was rated as fair during the last inspection in June 2018.

Designed by Osborn Engineering Co., the dam plays a crucial role in providing recreational opportunities for the surrounding community while also serving as a vital water resource. With its historical significance and importance in the local ecosystem, Iroquois Lake Dam stands as a testament to successful engineering and environmental stewardship in Ohio.

Year Completed

1960

Dam Length

1500

Dam Height

17

River Or Stream

UNNAMED TRIBUTARY TO THE CHAGRIN RIVER

Primary Dam Type

Earth

Surface Area

12.8

Drainage Area

0.06

Nid Storage

111.5

Hazard Potential

Significant

Nid Height

17
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.
View more

Area Campgrounds