Friday, 25 September, 2015
C.W. Bill Young Regional Reservoir
Based in Hillsborough County, FL, this project was for the construction of an above ground earthen reservoir with a designed capacity of 15 billion gallons – the largest in the state. The footprint of the reservoir covers approximately 1,100 acres of land in Hillsborough County.
The design of the reservoir called for embankments constructed from earthen fill, covered by a synthetic geomembrane material. The geomembrane was to be installed over the entire interior face of the embankment; an erosion control system was also to be installed. This system consisted of a layer of soil (embankment wedge) installed over the geomembrane followed by geotextile fabric with a soil-cement layer along the bench. Tampa Bay Water (TBW) awarded the construction contract for the project in the amount of $86,370,000.
The reservoir opened in June 2005. Unusual cracks appeared in the liner soon after completion. As a result, TBW conducted a series of studies and analyses and concluded that the cracking was primarily the result of excessively high water pressure from water trapped between the soil-cement layer and the geomembrane. In addition, various other construction defects were determined to have contributed to the unusual cracking observed in the soil-cement. Those defects exacerbated the effects of the excessively high water pressure in the wedge.
O’C&L was retained by the counsel to TBW to perform an analysis of the contractor's performance and to perform an evaluation of the construction management services. O’C&L was also tasked with the creation and presentation on an expert report of the results of the analysis.