Plumbers worked overtime across the South yesterday to repair thousands of water pipes that burst when they froze in record low temperatures, and frozen waterways slowed shipping and devastated some commercial fishing. Temperatures eased since record lows over the Christmas weekend, with thermometer readings in the 40s and 50s yesterday in Georgia. Homeowners and plumbers in Houston were working to repair thousands of pipes broken during three days of record-setting lows. "We're so busy I can't believe it," said Charles Rumsey, general superintendent at Crown Plumbing. "We're trying to hold the men's working days down to 12 hours, but some of them are getting 15 or 16 hours." Residents of some Houston apartment complexes had been without water since Friday. "They're dipping water from the pool and carrying it to their apartments to flush their toilets," said apartment manager Jean Williams. In Jackson, Miss., Mayor Kane Ditto said it was impossible to say when the city's water problems might end. Ditto said crews working to restore service to the remainder of 60,000 houses and businesses that had been without water were still finding new problems. He said there were 33 breaks in Jackson's 900 miles of water lines. The 50,000 residents of New Orleans public housing projects have had little or no water. City officials said water pressure dropped from a normal 65 pounds per square inch to about 47 because of pipe breaks. While water pressure plunged, the economic pressures of the freeze pushed wholesale produce prices higher. Supermarket prices are expected to climb within a week, experts said. The cold, which meteorologists called the harshest in Louisiana this century, ravaged the citrus industry in Plaquemines Parish (county) for the second time since 1983. Unlike growers in Florida and Texas, Louisiana orchard owners got most of the fruit picked before the freeze, but the trees were damaged. "It's a disaster second only to a big hurricane," said Luke A. Petrovich, president of the Plaquemines Parish Council. "We've lost our entire citrus industry, all our truck farms are wiped out, and the fishing industry will be hit real hard." Up to a half-foot of ice on Pittsburgh's three rivers has brought barge and boat traffic to a virtual standstill. Ice covers 70 percent to 100 percent of the Allegheny, Monongahela and Ohio rivers.