In the 1990s, Manassas eliminated public access to Lake Manassas, viewed above from Glenkirk Road near Gainesville. In 2004, the city adopted an ordinance that banned boating to protect the drinking water supply. (Jim Barnes/FOR THE WASHINGTON POST)

The Manassas City Council is considering reopening Lake Manassas to the public for recreational uses such as fishing and boating.

In a narrow decision, the council voted Tuesday to have staff members look at options for opening the lake for recreation. The staff is expected to study financial, operational, environmental and security issues associated with reopening the lake and to report back to the council in about six months.

The city-owned lake, southwest of Gainesville in western Prince William County, supplies drinking water to about 100,000 residents of Manassas, Manassas Park and Prince William, officials said. The city had eliminated public access to the lake in the 1990s, and in 2004 adopted an ordinance that banned boating to protect the drinking water supply.

In 2007, developer Brookfield Saranac sued the city, seeking access to the lake. The case was decided last year by the Virginia Supreme Court, which asserted that the city of Manassas has the authority to determine access to the lake. That decision opened the door for the discussion at the council’s work session Tuesday.

Council member Marc T. Aveni (R), a proponent of reopening the lake, said that Lake Manassas could be the “crown jewel” of the city’s parks and recreation program, while other council members raised concerns about costs associated with the project and possible threats to the city’s drinking supply.

“I believe it’s a resource that should be available to our citizens, and perhaps some others, for fishing, for . . . electric motor [boating], canoeing, kayaking,” Aveni said. “It’s a wonderful resource that’s nearby nature. I believe that the city would do well to look at ways that we could make that access available at the lowest possible cost.”

Aveni estimated that the city is spending $80,000 to $100,000 a year in law enforcement costs “to keep people off the lake.”

“My position would be that that money would be better spent finding some way to allow access to the lake,” Aveni said.

Council member Mark D. Wolfe (R) disagreed, saying that Manassas residents would have to bear the capital and operational costs associated with opening the lake to recreation, and said he thought that most of the people using the lake would live outside the city.

“I can’t conceive a scenario where the majority of the users of the lake . . . are going to be Manassas residents,” Wolfe said. “But with the city having ownership of the lake, we are likely to be the final, best source of funds.”

“To be very honest, I’m not interested in providing benefits for the citizens of Loudoun County and Prince William County,” Wolfe said.

Wolfe said that the city has other recreational needs, such as improved tennis courts and additional soccer fields, and that he would prefer to take a comprehensive look at those needs — including the lake — during the upcoming budget process.

Mayor Harry J. “Hal” Parish II (R) said he could recall many years ago when the town of Manassas, before it was incorporated as a city, had a shortage of drinking water. The lake was developed in the 1960s, he said, to assure a reliable supply of drinking water for Manassas residents.

“The first and primary responsibility for our lake, which belongs to the citizens of Manassas, is to provide quality drinking water at as low cost as we can try to provide it,” Parrish said. “I would be for opening the lake if we could . . . protect the lake absolutely and not have it cost the citizens of the city of Manassas a dollar.”

Parrish said he was particularly concerned that swimmers or divers might introduce invasive species of freshwater animals into the lake. He cited as an example the nonnative, invasive zebra mussel, which was detected upstream of Lake Manassas in the Millbrook Quarry. The zebra mussels were successfully eradicated from the quarry in 2006, according to a report from Thomas J. Grizzard, director of the Occoquan Watershed Monitoring Laboratory.

Parrish read excerpts from a 2005 WTOP news report that described how a burgeoning population of zebra mussels can block water pipes. The report said that utility companies in the Great Lakes region had spent billions of dollars trying to eradicate the mussels.

“For me, as a responsible fiduciary of the citizens of Manassas, I get very concerned about that,” Parrish said.

John M. Weber, chairman of the Manassas Utility Commission, said that a vote to proceed was not a vote to open the lake. “We’re just looking to see if we have permission from a high level to get some answers to all the questions,” he said. “I also believe that a lake which is permitted for fishing is going to be better controlled than one that is not.”

The council voted 3 to 2 in favor of Aveni’s motion to proceed with the study.

Barnes is a freelance writer.