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Reservoir repairs could cost $125 million

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By NEIL JOHNSON | The Tampa Tribune

Published: June 4, 2009

TAMPA - Fixing a flawed, 15 billion-gallon reservoir will leave it dry for two years and could cost $125 million, nearly the price tag of the 4-year-old reservoir.

Temporary repairs will allow Tampa Bay Water to fill the C.W. "Bill" Young Reservoir this summer and the following two, but a permanent fix is needed, said Gerald Seeber, the utility's general manager.

Some of the repair costs could trickle down to customers' water bills if the utility can't recover the money through its lawsuit against the reservoir's designer and builder.

The $125 million is a rough estimate for budgeting, Seeber said. The cost won't be known until bids are opened in three years.

"I don't have a lot of faith in that number," he said.

Cracks in the so-called soil cement covering over the reservoir bottom and sides kept the region's water supplier from filling it completely last summer and the reservoir went dry in March. Coupled with a persistent drought, the reservoir problems have prompted increased wellfield pumping and further strained the aquifer.

The reservoir provides an average of 30 million gallons a day. During the spring dry season, it's the lynchpin of the water supply for Hillsborough, Pinellas and Pasco counties, as well as the cities of St. Petersburg and New Port Richey.

The city of Tampa also is a member of Tampa Bay Water but relies on the Hillsborough River for most of its drinking water, buying water from the utility only when the river is low.

Though the cracks don't threaten the massive earth walls that form the reservoir in southern Hillsborough County, the underlying construction and design flaws must be resolved, Seeber said.

Engineers determined a layer of earth between the soil cement and a thick membrane buried in the walls to hold in the water caused the cracks, which cover 40 percent of the reservoir.

As water fills and drains from the reservoir, pressure changes in the saturated soil cause the soil cement to flex and crack. The soil cement is supposed to prevent erosion and protect the membrane.

The cracks appeared in December 2006, just a year after the reservoir opened. Since then, workers have filled them with grout as engineers investigated. Originally, engineers said the cracks were anticipated and purely a cosmetic flaw.

Work to repair the cracks ended in May, and the utility began filling the reservoir May 21 and plans to reach capacity this summer, said Jon Kennedy, senior manager for engineering and projects.

There are three options for fixing the problem, Seeber said.

Install a gravel-and-sand system to drain water from the soil layer and reinstall the soil cement.

Remove the soil cement and the layer of soil and put the soil cement directly on the membrane.

Add material on top of the soil cement to weigh it down.

In December, Tampa Bay Water sued the reservoir's designer, contractor and construction supervisor. The three companies – HDR Engineering, Barnard Construction and Construction Dynamics Group – have denied fault. The case is scheduled for trial in July 2011.

Ultimately, customers would pay the difference between repair costs and any harvest from the lawsuit. Tampa Bay Water is funded by its members through water sales; local utilities pass the costs on to customers.

Pinellas County Commissioner Susan Latvala, a Tampa Bay Water board member, said cost estimates are too preliminary to raise concerns now. It's more important to ensure the work fixes the problem.

"We can take our time to find the right solution," Latvala said.

Seeber proposes taking the next three years to select a contractor. Under his proposal, all bids would be reviewed by university experts, reservoir regulators outside Florida and reservoir owners.

The repairs would knock the reservoir out of service for two dry seasons. Construction would start in the early summer when the rainy season ends the need for water from the reservoir.

Seeber said other sources can make up the difference.

A planned expansion of a surface water treatment plant from 72 million gallons to 120 million gallons a day, along with wells and the utility's desalination plant will help meet regional demand, which can top 250 million gallons a day during the spring.

The utility has relied on those sources since the reservoir went dry March 12, though heavy wellfield pumping exceeded permit limits set by the Southwest Florida Water Management District.

The utility can also delay repair work for another year if the region is in a drought.

Reporter Neil Johnson can be reached at (813) 259-7731.

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