Two of the companies vying for the contract to fix Florida's largest reservoir are offering to do the work for less than Tampa Bay Water officials expected, but one wants to charge a higher price.
Two of the proposed repairs would cost less than the $125 million that Tampa Bay Water officials initially estimated as the price of fixing the continuing problem with repeated cracking in the reservoir's earthen walls.
But one would cost considerably more - in fact, it would cost $23 million more than the $144 million that the reservoir initially cost to build.
And none of that takes into consideration the cost of maintaining the reservoir over its projected 50-year life span.
The three companies made their pitches to the regional utility's board Monday, explaining not only how they would fix the reservoir but also how they would go about expanding the 15.5 billion-gallon reservoir by another 3 billion gallons - a move that would boost the price higher for all three.
There's no need for extra capacity for another two decades, according to St. Petersburg City Council member Karl Nurse, who serves on the utility's board. But general manager Gerald Seeber said it would be wrong not to investigate the possibility while the reservoir is being repaired.
Tampa Bay Water's goal is to get a contractor hired by Aug. 15 so design and permitting can start by Sept. 1 and construction can start by September 2012.
The utility opened the C.W. Bill Young Regional Reservoir in June 2005 to store water skimmed from the Alafia River, Hillsborough River and Tampa Bypass Canal.
The reservoir, named for the longtime U.S. representative from Pinellas County, covers about 1,100 acres in Hillsborough County.
The reservoir's walls consist of an earthen embankment as wide as a football field at its base, averaging about 50 feet high. An impermeable membrane buried in the embankment prevents leaks.
The embankment's top layer, a mixture of soil and cement to prevent erosion, began cracking in December 2006. Some cracks were up to 400 feet long and up to 151/2 inches deep. Workers patched the cracks, but the patches didn't last.
An investigation found water is getting trapped between the soil-cement lining and the membrane. As long as the reservoir is full, the trapped water remains stable. When the utility draws down the reservoir, though, pressure increases on trapped water in some areas, producing cracks and soil erosion.
The cracks have not been deemed a safety hazard to the structure, but utility officials say if they don't fix their underlying cause, then conditions could get worse. To fix it, they say, will require draining the whole reservoir and keeping it empty for two years.
However, the reservoir's designer, HDR Engineering, says the problem is not that serious and could be solved with a simple monitoring and maintenance program that would cost less than $1 million a year - a contention utility officials say is false.
The three companies vying for the contract to fix the reservoir are Granite Construction Co., Kiewit Infrastructure South and Skanska USA Civil Southeast.
Only one, Skanska, called for leaving much of the reservoir intact and instead just adding drainage systems and other reinforcement structures. Its price tag was also the lowest: $116 million for the repair work and an additional $53 million for adding room for 3 billion gallons more.
Kiewit called for digging out and replacing the soil cement and the membrane beneath it. The reason, according to Kiewit's design manager, Trent Dreese, is that its engineers believe the cracks showed a weakening of the reservoir wall and "additional failures are likely during drawdown" of the water for the repair.
Kiewit's proposed price: $121 million for the repair and another $53 million for raising the walls so another 3 billion gallons will fit inside.
Granite's proposal goes even further, calling for replacing the soil-cement with concrete blocks that would allow water to drain between them. That's why its proposed repair cost was the highest of all: $167 million. But its expansion cost was the lowest of the three: $34 million.
Utility officials hope to make HDR pay some or all of those costs - otherwise they may have to raise the rates they charge to cities and counties, which would likely pass those along to the customers around the Tampa Bay region.
Craig Pittman can be reached at email@example.com.