TAMPA - Before crews managed to dig up and repair a leaking sewer line early Tuesday, enough sewage overflowed into a Davis Islands canal to raise bacteria levels at a beach along the seaplane basin.

City workers went door to door Monday afternoon in neighborhoods near the canal, on the southern portion of the islands, telling residents to avoid the canal waters. The Hillsborough County Health Department posted advisories for people to avoid the water at what locals call ``dog beach'' or ``beer can beach.''

Water samples taken at the beach were unsatisfactory, and the health warning probably will not be lifted until next week, said Cindy Morris, environmental administrator for the health department.

Exact figures were not available, but possibly more than 250,000 gallons of sewage overflowed into the Currituck Channel, which meanders in east-west to the northwest of Peter O. Knight Airport, said Ralph Metcalf, director of the city's sewer systems.

The leak was noticed beside the canal, near a pump station, Sunday evening, Metcalf said.

Crews worked for more than 30 hours to find and fix the leaking section of the 12-inch line, which was buried 12 to 15 feet deep, Metcalf said.

If crews had shut down the pumping station to minimize the overflow, the results would have been worse, he said. The pressurized line serves more than half the islands' homes.

``The sewage would have backed up into everyone's house,'' Metcalf said. ``In this case there were no good options. We hate to see any overflow in the canal, but it was better than in the homes.''

The city notified state and county environmental and health agencies, Metcalf said. Bacteria levels should drop in a few days, he said.

Reporter Ivan Hathaway can be reached at (813) 835-2103.