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Mt. Gilead Lake Lower Dam

Location and Description

Conceptual design of completed dam.

Mt. Gilead Lake Lower Dam is part of Mt. Gilead State Park located off of State Route 95 in Morrow County. The dam was built in 1930 and has a maximum height of 20 feet. It also has a 90-foot-long concrete spillway that discharges water into Whetstone Creek. As a Class I high-hazard potential structure, a sudden failure of the Mt. Gilead Lake Lower Dam likely would result in the structural collapse of at least one residence or one commercial or industrial business and probable loss of human life. (Hazard ratings refer to the consequences of dam failure, not the dam's condition.)


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dam problem areas

dam problem areas

dam problem areas

dam problem areas

Dow Lake Dam: Statistics

  • Maximum Embankment Height: 20 feet
  • Length of Dam: 525 feet
  • Crest Width: 12 feet
  • Reservoir Surface Area At Top Of Dam: 14 acres
  • Storage Capacity at Principal Spillway Elevation: 38-acre feet = 12,382,300 gallons
  • Principal Spillway Type: 90' long concrete ogee weir
  • Emergency Spillway: None
  • Principal Spillway Crest Elevation: 1105 feet (msl)
  • Reservoir Surface Area at Principal Spillway: 11.4 acres
  • Lake Drains: 16-inch HDPE siphon
  • Dam Classification: Class I
  • Lake Constructed: 1930
  • Lake Inflow: Sams Creek
  • Total Drainage Area To Lake: 8.67 square miles
  • Lake Outflow: Whetstone Creek
  • Counties: The site is located in Morrow County at Mt. Gilead State Park
  • Communities: Mt. Gilead

Safety Issues

Mt. Gilead Lake Lower Dam currently has deficiencies that must be addressed to bring it into compliance with state dam safety standards. The deficiencies include insufficient storage-discharge capacity and seepage. There are additional concerns regarding the instability of the severely deteriorated concrete spillway and the entire dam embankment, along with concerns about the presence of trees and brush on the dam. ODNR previously contracted with Jobes & Henderson, and SME, to provide investigations and preliminary design alternatives. These investigations of the dam structure revealed the concrete spillway is deteriorated and has a very low safety level.

Risk Reduction

ODNR has processed a contract amendment with Michael Baker Jr., Inc. to provide additional analysis, final design and construction documents for competitive bidding. This work will include an assessment of the lake's Class II Upper Dam to determine what repairs may additionally be needed and if such work can result in a reclassification of that structure upon completion.

Long Term Plan

Routine inspections and maintenance of the dam will continue. An emergency action plan will be revised and shared with local emergency management officials once it is completed.


News Releases

  • No news release items at this time.

Supporting Documents

  • None

Media Coverage


To request more information you may write to:

Ohio Department of Natural Resources
Dam Risk Reduction Project
2045 Morse Road, Building E-3
Columbus, Ohio 43229

or send an email communication to