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Tuscarawas Diversion Dam-Portage Lakes

Location and Description

The Tuscarawas Diversion Dam located adjacent to Firestone Country Club in Summit County is part of the Portage Lakes State Park system. The dam is a zoned earth fill embankment with a concrete gravity ogee spillway. The main outflow flows into Long Lake by way of the Tuscarawas River. However, flow can be diverted to East Reservoir through a feeder canal. The embankment is about 1,000 feet long and has a maximum hydraulic structural height of 26 feet. Harrington Road runs along the crest of the embankment and the Harrington Road bridge extends over the spillway structure. All transportation infrastructure on the embankment is maintained by Summit County.

The drainage area of the lake is 35.4 square miles and the lake has a normal pool surface area of 83 acres. As a Class I high-hazard potential structure, a sudden failure of Tuscarawas Diversion 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.)

Click here for more about the Dam Risk Reduction Program.

dam deterioration

dam deterioration

spillway bridge deterioration

Tuscarawas Diversion Dam: Statistics (previous structure)

Prior to completion of dam risk reduction construction the dam included these characteristics.

  • Maximum Embankment Height: 26 feet
  • Length of Dam: 1,000 feet
  • Crest Width: Defined by the two-lane Harrington Road/no berm
  • Reservoir Surface Area At Top Of Dam: Normal pool surface area of 83 acres
  • Storage Capacity at Principal Spillway Elevation: 443 feet = 144 million gallons
  • Principal Spillway Type: Concrete gravity ogee
  • Emergency Spillway: None
  • Principal Spillway Crest Elevation: 995 feet above sea level
  • Reservoir Surface Area at Principal Spillway: 83 acres
  • Lake Drains: (2) 4-foot concrete drains at the spillway
  • Dam Classification: Class I
  • Lake Constructed: 1956
  • Total Drainage Area To Lake: 35.4 square miles
  • Lake Outflow: Tuscarawas River
  • Counties: The site is located beneath Harringrton Road in Summit County, adjacent to the Firestone Country Club
  • Communities: Portage Lakes, City of Akron, Summit County

Safety Issues

The dam currently does not meet the minimum design storm standard. Also, the concrete spillway and spillway walls are deteriorated and in need of structural repairs. Existing gatehouses and mechanical gates are in need of replacement. The upstream and downstream shoreline erosion protection is displaced and in need of replacement. The existing five-span, continuous concrete slab bridge is in need of replacement.

Risk Reduction

Current work includes repairing the existing spillway, installing new automated mechanical gates, rehabilitating the existing feeder canal outlet structure, completing electrical improvements to the existing gatehouse, and providing overtopping protection. Overtopping protection involves placement of roller compacted concrete and steel sheet piling on/along the downstream face and crest of the embankment.

Through a partnership with Summit County, the project involves replacement of the existing Harrington Road bridge and full depth replacement of asphalt on the roadway extending along the dam crest. DLZ is the engineer of record. Dam risk reduction project costs are approximately $5.5 million.

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.


Harrington Road Closure - Harrington Road has been reopened to motor vehicle traffic as the Tuscarawas Diversion Dam risk reduction and bridge replacement projects are substantially complete. Some remaining work to the dam gatehouses during winter and installation of measurement gauges may require an intermittent and temporary, daytime-only lane closure on the Harrington Road bridge. Signs will be posted accordingly. (posted 12/29/14)

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