Lilley Lake Dam

Lilley Lake Dam is an earth dam located in Warren County, Ohio, built in 1954. It carries a High hazard potential classification and has a poor condition assessment.

About Lilley Lake Dam

The primary purpose of Lilley Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Stephen R. Lilley (private). It impounds the Tributary To Halls Creek near Oregonia.

The dam stands 43 feet tall and stretches 970 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 210 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1954, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 05/16/2024.

At 43 feet, this dam is taller than 89% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Ohio dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardPoor ConditionEmergency Action Plan: No

Location

StateOhio
CountyWarren
Nearest CityOregonia
River/StreamTributary To Halls Creek
Coordinates39.38444, -84.13389

Physical Characteristics

Dam TypeEarth
NID Height43 ft
Dam Height43 ft
Dam Length970 ft
Year Completed1954 (72 years old)

Storage & Hydraulics

NID Storage210 acre-ft
Max Storage210 acre-ft
Normal Storage149 acre-ft
Surface Area9 acres
Drainage Area0 sq mi
Max Discharge45 cfs

Ownership & Safety

PurposeRecreation
OwnerStephen R. Lilley
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentPoor
Last Inspection05/16/2024
Emergency Action PlanNo

Identifiers

NID IDOH00547
Federal IDOH00547
More InfoState Dam Safety Program

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