The switch from deluge to drought continued throughout the Bay watershed in November. After 1998 opened up with the wettest six months on record, things have gotten steadily drier, with much of the watershed suffering drought conditions.

That was reflected in the November flows into the Bay from its tributaries, according to the U.S. Geological Survey. Freshwater flows into the Bay averaged 9.3 billion gallons a day - far below the November long-term average of about 38 billion gallons a day.

The record low for November during the 48 years USGS has tracked flows was 1964, when 9 billion gallons a day entered the Bay. But the flow down the Susquehanna, the Bay's largest tributary, averaged 3.6 billion gallons a day, a record November low for the river. The Potomac's 1.3 billion gallon a day average was the fifth lowest on record for November.

After exceeding the average for the first six months of the year, flows have been below average every month since June. While it is typical for flows to decline in the summer and early fall, they usually begin to rise again in the late fall, according to the USGS.

The high flows of the spring raised concerns because they flush unusually large amounts of nutrients and sediments into the Bay, clouding the water and blocking sunlight to underwater grasses that provide important habitat. In addition, nutrient-fueled algae blooms sink to the bottom and are decomposed in a process that depletes the water of oxygen. This year's oxygen conditions in the Bay were among the worst on record.

But low flows bring concerns of their own, including raised salinity levels because of the lack of freshwater. Some scientists were worried that low salinity would allow the oyster-killing parasite, MSX, to re-invade Maryland's portion of the Bay after being pushed almost entirely out by freshwater flows.

The Susquehanna River Basin Commission issued a drought declaration and called for a voluntary 5 percent reduction in water use. With reservoirs dried out in parts of Pennsylvania, people have resorted to taking sponge baths and washing their clothes in neighboring towns.

The combination of dry weather and depressed prices for crops and livestock has made this the worst year for Virginia farmers in at least two decades. Forty localities have applied for federal drought assistance.

In Maryland, Allegany County officials have been struggling to keep drinking water flowing to about 2,000 homes and businesses along Georges Creek, a Potomac River tributary that has nearly run dry.