GROWTH is a hidden co-conspirator in Maryland's severe drought, teaming with the lack of rainfall to squeeze water reserves.
While scientists and state officials are less than conclusive in their judgments of how much supply trouble is created by the steady increase of homes, roads and parking lots across the landscape, most agree that development wastes significant quantities of water.
That's not just because it provides more thirsty customers, but also because of what it does to the water that falls from the sky. Instead of seeping into the ground and replenishing the underground aquifers that feed wells and supplement reservoirs, rain often rushes down gutters and across pavement into fast-flowing streams that can drain it away from where it's needed.
"The suburbanization of a rural landscape dramatically affects the natural water flow," said Roy W. Kienitz, the state secretary of planning. "Sprawl development reduces our ability to store water in one of the places we need it, which is underground."
Washington and its suburbs in Maryland, Virginia and eastern West Virginia, an area that developed 343,300 acres between 1982 and 1997, are losing 23.8 billion gallons to 55.6 billion gallons to runoff every year, environmentalists estimated in a report released last week by American Rivers, Natural Resources Defense Council and Smart Growth America.
Researchers, whose calculations assumed that impervious surfaces make up 15 percent to 35 percent of new developments, concluded that "an essential and costly resource is being squandered at an alarming rate."
"I don't think we've caused the drought, but we've certainly not helped," said Dru Schmidt-Perkins, executive director of 1000 Friends of Maryland, an anti-sprawl organization. "I don't believe we've been doing the calculations to figure out, how much development can we sustain in a particular area without adversely affecting our drinking water?"
But Tom Ballentine, director of government affairs for the Home Builders Association of Maryland, believes that the report's findings don't apply to Maryland because the state is at the forefront of the Smart Growth movement - the type of development championed in the study.
Storm-water management guidelines enacted in 2000 also encourage more infiltration than old systems, he said. New methods developers are trying include channeling rain across large grassy spaces to give it a chance to seep in before it's funneled away to streams.
"The Central Maryland area is 67 percent below its normal rainfall," Ballentine added. "It's a weather problem, not a development problem."
Though the report estimates that the average person uses 100 gallons of water a day, the good news is that population growth hasn't tapped the Baltimore area's main water system nearly as much as it could have.
Over the past 10 years, the system's customer base - in Baltimore, eastern Howard, northern Anne Arundel and most of Baltimore County - grew 12.5 percent to 1.8 million people. Daily water use grew only by 3.2 percent, from 247 million gallons to 255 million gallons.
But that is not the case in many outlying suburbs where growth is outstripping water supplies. Just as many jurisdictions consider the condition of schools and roads before they approve development, more communities are now including water on the "adequate public facilities" list.
"We're more vulnerable to drought because of this population growth," said Mark Svoboda, climatologist at the National Drought Mitigation Center at the University of Nebraska-Lincoln. "Even if we're in good times, some of these areas are really starting to question, how much growth and development can we really take on?"
The city of Frederick, which is suffering through its second-worst drought but with its lowest water supply ever, has been under a growth moratorium since last year after a 1990s population boom that came without an increase in water sources. The city is drilling three wells while officials work on hooking up to the Potomac River, a process that will take four years.
The moratorium "saved us our water supply," said city spokeswoman Nancy Gregg Poss. "We would have long run out of water had we still been developing. ... We need to get through this crisis for the people who are here before we can think about the future people coming into Frederick."
Mayor Jennifer Dougherty, who took office in January, announced recently that the city could have to truck in as much as 4 million gallons of water a day if supply drops much more.
Westminster - which is also considering whether to buy unprocessed water at a cost of $12,000 a day - passed ordinances in February that allow officials to keep out-of-towners from hooking into the water system if it can't take more users.
More than half the 31,000 customers live outside Westminster's limits, and that's also where most of the growth has come, said Mayor Kevin Dayhoff. City officials have been working on two new water sources for several years, but they had no control over development around them.
'Held to consequences'
"We've been unhappy that we've been held to consequences of decisions that we weren't able to participate in," Dayhoff said.
In Mount Airy, the supply in the eight community wells is down but not nearly at a danger point. Town Council President Frank Johnson is convinced that water-related growth controls saved the day.
Mount Airy's population boomed in the past 10 years, from about 3,700 residents to 7,800. Like Frederick and Westminster, the town instituted water conservation measures.
But Mount Airy also requires most developers to find new sources of water before they build - 50 percent more than the newcomers will need.
For good measure, officials expanded a building moratorium in August to include all subdivisions.
"In Frederick, they overbuilt past their water supply," Johnson said. "It would have been very easy for us to be in a very dire situation if these requirements hadn't been there."