CLEARWATER — Tampa Bay Water has begun draining its 15.5 billion-gallon reservoir to get ready for repair work on its persistent cracking problem, a utility official said Monday.
"We're on a course now to take it all the way down to the bottom," Alison Adams, a senior manager with the regional utility, told the agency's governing board.
Tampa Bay Water is sending 45 million gallons of water a day out of the reservoir to its customers, which means it will be completely dry by the end of December, she said.
Repair work on the C.W. Bill Young Reservoir — named for the congressman who steered federal funds to its construction — is scheduled to begin in January and last 22 months.
To make up for idling the reservoir, Tampa Bay Water has begun running its idled desalination plant. Adams said the plant, which has a maximum capacity of about 25 million gallons per day, has been producing 12 million a day since August, so far with no signs of trouble.
The utility also takes water from the Hillsborough and Alafia rivers and the Tampa Bypass Canal, as well as pumping millions of gallons of water from underground.
But damage to lakes and wetlands in the 1990s persuaded state regulators to limit how much water the Tampa Bay region can pull up from the aquifer. Exceeding the 90 million-gallon-per-day limit brings the risk of fines.
Tampa Bay Water is supplying about 155 to 160 million gallons to utilities in Pinellas, Hillsborough and Pasco counties, Adams said, while keeping its consumption of groundwater below 90 million.
The utility opened the reservoir — the largest in the state — in June 2005 to store water skimmed from the two rivers and the canal for use in times of drought. The reservoir, which cost $146 million, covers about 1,100 acres near Fort Lonesome 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 concrete to prevent erosion, began cracking in December 2006. Some cracks were up to 400 feet long and up to 15 ½ inches deep. Workers patched the cracks, but the patches didn't last.
Tampa Bay Water sued the reservoir's designer, but lost. That case is now on appeal.
Meanwhile the utility's board voted to expand the reservoir by 3 billion gallons during the repair job. But this spring the state Department of Environmental Protection warned that the utility would not be allowed to do that because of a concern about sinkholes in that area. As a result, the utility's plans have been scaled back to a repair job. That cut the cost from $163 million to $129.4 million. The agency plans to issue up to $85 million in bonds to pay for the repairs and other capital projects.
Craig Pittman can be reached at firstname.lastname@example.org.