Kiewit Infrastructure was selected by Tampa Bay Water’s board of directors in August 2011 to repair the regional reservoir. Kiewit was selected because the company’s fix was a strong technical solution that would ensure the long-term reliability, functionality and performance of this vital facility.
Kiewit’s solution to repair the cracking around the reservoir included a comprehensive drainage system to prevent the buildup of water pressure behind the soil-cement slope. Steps in the renovation included:
- Removing the existing soil cement on the interior face of the reservoir.
- Digging out the soil wedge between the soil cement and the geomembrane.
- Removing the geomembrane, a synthetic liner that serves as a seepage barrier, below the soil wedge.
- Installing equipment in the embankment to monitor drainage.
- Covering the embankment with a new, more durable liner.
- Building a thick soil-cement, stair-stepped base of support around the bottom of the interior face.
- Adding a 9-inch-thick layer of drainage rock on the slope, and, at the bottom of the drainage, placing rock-filled, wire baskets as a drainage outlet around the entire reservoir just above the thick soil-cement, stair-stepped base.
- Placing new, stair-stepped soil cement—approximately twice as thick as what was there before—on top of the slope to control erosion.
Kiewit will monitor and maintain the reservoir until it is drained twice or for five years from the fall 2014 completion date to ensure that the reservoir, specifically the new erosion protection and drainage systems, are operating properly.