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Tampa Bay Water recommends spending $163 million to expand and repair reservoir

The gray lines visible on the C.W. Bill Young Reservoir are patches that have been placed on cracks in the lining.

SKIP O’ROURKE | Times (2009)

The gray lines visible on the C.W. Bill Young Reservoir are patches that have been placed on cracks in the lining.

Tampa Bay Water's staff is recommending the board hire a Nebraska-based company to fix the cracks in its reservoir — and also recommending the board approve expanding its 15.5 billion gallon capacity by another 3 billion gallons.

The repair itself is expected to cost $121 million — nearly as much as the $140 million facility cost to build in the first place. The expansion would add an extra $42 million to the price tag, according to the utility's staff, making a total bill of $163 million.

"It's a tough call from a financial perspective," the utility's general manager, Gerald Seeber, said in an interview.

Demand for water in the Tampa Bay area has fallen because of the economic slump. So why expand the reservoir now?

Two reasons, according to Seeber: It's less disruptive to do the work during the repair than to try to do it after it's fixed; and the $42 million price is less than the estimated $200 million to $300 million to build a second reservoir.

But Seeber faces a tough sell with at least one of the utility board's members, St. Petersburg council member Karl Nurse, who contended there's not enough demand for water to justify the expense.

"We won't need it for 15 or 20 years," Nurse said. "This is a rate increase that's really unnecessary."

Instead of raising the walls of the reservoir, he said, it would be better to spend the $42 million on promoting water conservation so people would use even less of it.

The recommendation to hire Kiewit Infrastructure Group and expand the reservoir, unveiled Friday, is scheduled to be voted on by the utility board on June 20.

The 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 work is likely to last two years, during which the reservoir will have to be emptied.

Paying for the work will depend on the outcome of a trial slated to begin next month. Tampa Bay Water is suing the reservoir's designer for damages, but if those do not cover the cost, then its rates may have to go up, with the average user seeing a boost of about $1 a month.

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 covers about 1,100 acres in Hillsborough County.

The 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, but utility officials say if they don't fix their underlying cause, conditions could get worse.

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.

Kiewit's proposal for the fix calls 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 price tag for the work was neither the highest nor the lowest proposal. Skanska USA Civil Southeast, which called for leaving much of the reservoir intact and adding drainage systems and other reinforcement structures, said it would charge $116 million for the repair work and an additional $53 million for the expansion. Granite Construction Co.'s proposal called for replacing the soil-cement with concrete blocks that would allow water to drain between them, at a cost of $167 million. But its expansion cost was the lowest of the three: $34 million.

Kiewit, founded by a pair of brickmakers in Omaha, Neb., in 1884, is usually listed among the top 10 contractors by Engineering News Record, with 2010 revenue of almost $10 billion, according to the company's website.

Among its notable projects are building the Fort McHenry Tunnel beneath Baltimore Harbor; rehabilitating the Francis Scott Key Bridge over the Potomac River in Washington, D.C.; and fabricating Bullwinkle, the world's largest freestanding oil production platform in the Gulf of Mexico. It has built dams and reservoirs in California, as well as pump stations for Everglades-related projects in Florida.

Craig Pittman can be reached at craig@sptimes.com.

Tampa Bay Water recommends spending $163 million to expand and repair reservoir 06/10/11 [Last modified: Saturday, June 11, 2011 12:19am]

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