Release of Reservoir Water Puts Drought to the Test

Potomac Flow to Show if Supply Is Adequate

In an extraordinary measure aimed at determining whether the Washington region truly is in a drought, the U.S. Army Corps of Engineers released a torrent of water yesterday from a dam in far Western Maryland to test how long it will take the water to reach this region.

The release of 200 million gallons of water a day through tomorrow from the Jennings Randolph reservoir will allow experts to fill in a crucial data point they say is missing from their drought predictions.

Despite the desiccated cornfields and front lawns, the declarations from political leaders and this fall's unseasonable heat, water experts remain uncertain whether the region's dry spell will ultimately lead to a drought for the water supply.

The Interstate Commission on the Potomac River Basin is predicting there is only a 1 percent chance that major water suppliers will have to tap backup sources through the end of the year. Without the water flow data from the dam, though, it doesn't know for certain.

"It's very rare to have full reservoirs late in the season with low flows [in the river], so we are taking advantage of it to test the time of travel from the reservoir to the intake," said Erik Hagen, the commission's director of operations.

In 1992, the last time the Corps of Engineers tested water flow from the reservoir, about 150 miles northwest of the District, it took nine long days to go downriver to the Potomac basin. That was one of the worst dry spells the region has experienced recently, a year when the water flow in the Potomac could not sustain the region's water supply needs. The nine days become something of a benchmark: If it takes longer for the water to get downstream this week, experts could decide that they have a problem.

Other indicators suggest that the region has not reached a "hydrological drought": The Potomac is coursing through Washington at about 700 million gallons a day, below normal but well above historic lows. Most major reservoirs have levels adequate for the region's drinking, washing and watering needs.

"The Washington area water supply is in excellent shape," Hagen said.

That is little solace to farmers across Virginia and Maryland who lost as much as 60 percent of their crops this summer, or to homeowners who have been asked to curtail lawn watering and shorten showers as the hot, dry weather continues in October.

Yesterday, the temperature reached 92 degrees at Reagan National Airport, the warmest day this month, according to the National Weather Service. It was one degree shy of the record for Oct. 7, set in 1941, and far above the average high of 72 degrees or last year's crisp 58 degrees. At Dulles International Airport, the temperature hit 91, breaking the 1963 record of 86 degrees.

Weather forecasters predict a hot day today, but a cold front should arrive tomorrow night and bring rain and cooler temperatures.

The conditions have prompted some public officials to impose water conservation measures, primarily in counties with heavy agricultural bases and with new development taxing the water supply. Some smaller reservoirs are at critical lows.