"It's not the heat, it's the humidity," goes the oft-quoted, much-mocked complaint. But this summer it's more moisture--in the form of rain--that tops the wish lists of local water authorities and gardeners alike.

The current drought, which began last summer, is now the worst in 30 years, and the second worst since the government began keeping records in the 1880s.

Locally, Maryland has been hardest hit, and on Thursday, Gov. Parris Glendening made it official: Standing before Liberty Reservoir in Carroll County, where the water level is 24 feet below normal, Glendening declared a statewide drought emergency. Unless there is a major rainfall or a substantial reduction in consumption, he said, there is only a 35-day supply of water for the Baltimore area.

Over the past six months, precipitation in the region extending from west central Virginia to the Chesapeake Bay has been as much as 50 percent below normal. Drought conditions are normally thought of as a 15 percent or greater deficiency over a six-month period.

And no rain means that the flow of streams and rivers is much diminished.

Consider the Potomac.

The river's normal flow for June is about 4.9 billion gallons per day (BGD). By comparison, this summer has been a disaster. In June, the river's daily flow averaged about 1.5 BGD--about 30 percent of the normal flow--which is a new record low. (The previous record low for June was 1.7 BGD recorded in 1969). To make matters worse, diversions from the river for municipal use that month were about 25 percent greater than in June 1998.

Last month, the pattern continued, with the river's flow dropping to 0.7 BGD on July 15.

Don't hold your breath for relief. There are two ways droughts are broken, the National Weather Service says. One way involves waiting for fall. The other way? A tropical cyclone. But that, the National Weather Service notes, includes "some ugly side effects."

Sources: U.S. Geological Survey, National Weather Service Baltimore/Washington, National Drought Mitigation Center at the University of Nebraska-Lincoln.