Assessment, design, permitting, bidding services, and construction administration for a new labyrinth spillway

Indian Lake Dam and Spillway Improvements

The Indian Lake State Park spillway and embankments currently impound approximately 45,000 acre-feet of water at normal pool, covering approximately 5,000 acres. The Ohio Department of Natural Resources (ODNR) partnered with Stantec to assess spillway conditions and determine a course of action.

Our team provided a full spectrum of services including preliminary site review, geotechnical and structural evaluation, surveying, hydrologic and hydraulic analysis, preliminary design, cost estimation, permitting, final design, bidding, and construction administration. The hydrologic and hydraulic modeling indicated the existing spillway capacity did not meet the required 100% probable maximum flood (PMF), so we developed alternatives to increase spillway capacity, install a gated spillway structure, and used roller compacted concrete (RCC) for overtopping protection.

Final design included replacement of the existing ogee spillway with a labyrinth spillway to efficiently pass flow and provide for additional capacity. The multi-tiered spillway was designed to simulate the original flow conditions up to the 100-year storm event.