Passersby on Falls Road may catch a quick glimpse of what looks like a misplaced limestone mausoleum sitting atop a slight grassy berm in front of the Village of Cross Keys.

What they're looking at is one of three surviving Greek Revival valve houses that once played a vital role in Baltimore's municipal water system.

The 16-foot-by-11-foot structure, originally called the Harper Waste Weir by the city water department, was designed by James Slade, the city engineer for Boston and a consulting engineer for the Baltimore Water Works. The building was completed in 1860.

Running beneath the valve house is a 6-foot oval-shaped aqueduct that moved water by gravity 3.7 miles from Lake Roland to the now-defunct Hampden Reservoir.

Water was then pumped into the city from the reservoir. The valve house's other function was to hold water for use by the Fire Department in case of a fire near today's Meadow Mill.

Its value came to an end in 1915, when Lake Roland became polluted and the entire system was abandoned by the city, which replaced it with Loch Raven Reservoir.

In the 1960s, the Rouse Co. purchased the surrounding property from the Baltimore Country Club — including the valve house — and built the Cross Keys development.

The Victorian-era confection, which had suffered from decades of neglect and was falling into disrepair, caught the eye of Cross Keys resident Jim Holechek, 83, a retired Baltimore public relations executive, author and preservationist.

In 2009, Holechek launched an effort to raise funds for its preservation. When that came to fruition, he turned his attention earlier this year to getting the structure declared a city landmark by the Baltimore City Commission for Historical and Architectural Preservation.

In addition to his other roles regarding the valve house, Holechek happily accepted the position of valve house keeper.

Earlier this week on a rainy afternoon, he gave me a guided tour of his baby.

"Don't worry, those grates look rusty but they won't give way. They weigh nearly a ton and you can step on them," he assured me as I cautiously stepped into the damp, musty room.

Below, swiftly moving water rushed on its way to a discharge pipe that dumps it into the nearby Jones Falls. For a moment, the sights and smells reminded me of "The Third Man," when Orson Welles attempts to escape the pursuing police in the sewers of Vienna in the classic 1949 film.

"That water is coming from Roland Park," said Holechek, who added that, when it was operational, water department workers periodically had to descend into the "waste weir" to remove branches, logs, leaves and other trash that collected there.

In the center of the floor are two large, elliptical steel grates and above them stand two valve pedestals whose hand-cranked worm drive — which took 30 minutes to open — raised or closed one of the two steel sluice gates that lie 15 feet below the floor of the structure.

When Holechek got involved with the valve house, small trees were growing through the slate roof. A heavy grated steel door with a small screened oval window — a 20th-century addition — closed off the entrance.

"The slate was removed and saved and, after the roof was fixed, was reinstalled by Ruff Roofers," said Holechek, who designed a new iron front door that was made at the G. Krug & Son foundry in downtown Baltimore.

"There was some limestone missing in a corner so I went to the Cockeysville quarry, where the original stone had come from, and they gave me some stone dust that I mixed and used to repair it," he said.

But the best news, which he said he learned this week, is that it looks as though the valve house is on its way to becoming the city's newest historic landmark.

"I encourage people to come by and see it," he said.

The other two extant valve houses that are architecturally similar were constructed in 1862. One stands at Lake Roland, near the dam, while the other is on the SPCA property in the 3000 block of Falls Road in Hampden. It once marked the Hampden Reservoir, which was filled in and is now Roosevelt Field.

fred.rasmussen@baltsun.com