Slide Ridge Culvert Replacement

Slide Ridge produces frequent and violent flows of varying amounts of water, soil, boulders and debris down a natural and manmade drainage channel, frequently overtopping the South Lakeshore Road on the west side of Lake Chelan. The project team evaluated the hydraulic conditions of the existing channel from the apex of the Slide Ridge alluvial fan to Lake, evaluating the feasibility of replacing an existing 96-inch culvert with a new opening and making local modifications to the basin and channel. A feasibility study identified several alternative solutions and the benefits and risks associated with the alternatives. The final solution included raising of the roadway several feet, in addition to lowering and enlarging the channel A single span deck bulb tee bridge supported on spread footings carries the roadway over the new channel.

• Lowered over 1,000 feet of channel up to 18-ft at the bridge, with berm heights up to 28-ft tall
• FEMA funding
• A strike bar is installed on the uphill side of the bridge to protect the bridge from impact damage if boulders come down the channel higher than the design criteria

Additional Services Provided by KPFF:

• Bridge Design
• Vehicular Bridges
• Emergency Management

Additional Services Provided by Sub-consultants:

• Hydraulic/Channel Design
• Geotechnical Engineering
• Stormwater Design
• Roadway Design
• Detour Road Design