Opposum Lake Dam Rehabilitation
Lower Frankfort County, PA
This project consisted of a complete replacement of existing concrete spillway with embankment modifications. The existing spillway was 60’ wide ogee weir with sloped spillway walls. The new construction consisted of up to 36’ high battered concrete walls, 240’ of 14’ high weir walls. A total of 3700 CY of concrete was placed on this project.
Along with a 900’ long parapet wall to raise the crest of the dam, the embankment was modified with a new toe drain. Additional work included extending the conduit 75’ to allow the new embankment to be flattened to a 3:1 slope. This activity required establishing a borrow on site for the 35,000 CY earthfill placement.
As with any dam project, control of water is a major concern with DEP Dam Safety. This lake was drained prior to construction however inflows from rain events quickly raised the level of the basin. Being prepared and planning for these events was key to success on the project.
Pennsylvania Department of General Services
PA Fish and Boat Commission