Several surface water options, including proposed reservoirs at Union Mills and Gillis Falls, are featured prominently in the county's updated water and sewer master plan.
After the county commissioners signed off on it last week, the plan now awaits approval from the state Department of the Environment.
In addition to the reservoirs, the county has also agreed to possible intakes from streams: one for Mount Airy at Gillis Falls, and one for Westminster at Big Pipe Creek.
"We can't just rely on groundwater," said County Planning Director Steven C. Horn. "We are poised to consider other alternatives we've been planning for since the 1970s."
Officials said such measures are necessary to continue to direct residential and industrial growth throughout Carroll.
New state regulations have led to water deficits in Westminster, Mount Airy and Taneytown.
The state environmental department has said that those municipal systems cannot meet current water demands during times of drought.
Residents living near the site of the proposed Union Mills reservoir have criticized the project and have formed the Union Mills Watershed Association. Opponents are concerned that the 325-acre reservoir would eat up land already under easement through the county's farm preservation program.
Despite the opposition, county officials said both reservoirs have been on the books for decades, yet just recently became possible because of changing state and federal regulations.
"It's only because we were told the reservoirs could not happen back in 1990, but these reservoirs have always been on the master plan," Commissioner Julia Walsh Gouge said. "Since we brought back attention to them, suddenly everyone is upset, but they've always been there."
The reservoirs, which could take 10 years to complete, aren't included on the county's six-year capital budget plans. The county has not figured out ways to pay for such costly projects.
"Water has thrust itself into our budget picture in a way I could not have imagined this time a year ago," county budget director Ted Zaleski said. "But we don't have a river running through Carroll County, so it seems like all we're left with is reservoirs."
The county faces other extensive water costs, concerning Total Maximum Daily Loads under the federal Clean Water Act and new requirements for managing stormwater, Zaleski said.
The county will have to upgrade technology at wastewater treatment plants to limit pollutants, or the Total Maximum Daily Loads, it discharges into its reservoirs and other bodies of water.
"What's clear is there are going to be projects that require a lot of money," Zaleski said.
In Westminster, where water shortages have led to a building moratorium since September, officials hope to have an agreement soon with the state to allow some development to move forward.
Drawing water directly from Big Pipe Creek, constructing a 7-mile emergency pipeline between Medford Quarry and the city's Cranberry Reservoir and from Hyde's Quarry off Jasontown Road are all options that could help alleviate Westminster's deficit, according to the water plan.
Both Mount Airy and Taneytown, which are barred from drawing more water from their existing wells, have agreements with the state to allow a limited amount of development to move forward.
Taneytown plans to develop a 1.5 million-gallon surface water source fed by Big Pipe Creek, officials said.
Since Mount Airy's former plan to tap into the South Branch of the Patapsco River is off the books, the town is redrafting its agreement with the state, county officials said.
Mount Airy's current plan to drill for wells at Gillis Falls or pursue a direct intake there better meshes with the county's vision, Horn said. He said it could assist the county's efforts to build a reservoir there.
The county has received numerous letters, including those from Rep. Roscoe G. Bartlett and other members of Congress, opposing elements of the plan for the Union Mills reservoir.
Many of those letters urge the county not to destroy any of the neighboring 300-acre farm of Whittaker Chambers, which has been designated a National Historic Landmark since 1988.
There, Chambers hid secret documents (known as the Pumpkin Papers), purportedly stolen by accused Communist spy Alger Hiss, in a hollowed-out pumpkin on the farm.
Instead of building a massive reservoir, Chambers' son, John Chambers, asked if water from Big Pipe Creek could be stored in elevated tanks. Chambers is also concerned about possible leaking chemicals from the site of the former John Owings Landfill, which borders the reservoir's location.
County officials have said that the reservoir's definitive boundaries have not been decided, but that it should not affect the Chambers farm.
Tom Devilbiss, chief hydrologist for the county's bureau of resource management, said the county has 90 percent of the land required for the Gills Falls reservoir and 70 to 80 percent of the land for Union Mills.
"The actual area to be flooded could be flexible," Devilbiss said. "We have done nothing engineering-wise since the 1970s."