Two reservoirs, as seen from the observation deck of the George Washington Masonic National Memorial in Alexandria, Va. The smaller square one, left, went into service in 1852 and is still used. The oval one was used from 1875 to 2000. (John Kelly/The Washington Post)
Columnist

My wife and I hosted relatives this summer and one of our stops was the George Washington Masonic National Memorial in Alexandria, Va. I visited once before, over 30 years ago, and had forgotten there is a small reservoir out back. I’m wondering if you know what the reservoir’s purpose was/is. I also wonder if you know what the brown basin to the reservoir’s left is.

Richard Rogers, Kingstowne, Va.

Answer Man suspects that we’re all sick of water by now, what with this summer’s rain and the recent hurricane. But it’s worth remembering that though we have a surfeit now, a water supply can’t always be depended upon. That’s why we need reservoirs.

There are two behind the Masonic Memorial in Alexandria and they are very old indeed. The older of the pair is the one closer to Duke Street. It was completed in 1852 and can hold 3 million gallons of water. Next to it is a ­14-million-gallon reservoir constructed in 1875.

The larger reservoir was taken out of service in 2000, but the 1852 reservoir is still in use, said Terry Knepp, operations superintendent for Virginia American Water, the utility that owns the system.

Knepp knows his H20. He said that before 1850 — when the first public water company was chartered in the city — Alexandrians got their water from wells dug about 30 feet into the ground. The problem with shallow wells is that they are easily contaminated.

The solution was to build a reservoir on Shuter’s Hill on what was then the edge of town. Water came from nearby Cameron Run and from a well dug on-site.

Water started flowing through the first cast-iron pipes — seven miles of them — on June 15, 1852. Benjamin Hallowell, Alexandria Water’s first director, noted that it was rusty at first, but after a few weeks the water was “very clear and pure, and we think will compare, favorably, with the water introduced into any City in our country.”

The reservoir itself became an attraction, noted for its “tasteful and creditable appearance.” Its berm-like walls were higher than the surrounding landscape so water could be fed by gravity through the pipes. (Pumps help move the water along now.)

Said Hallowell: “From the top of the bank of the Reservoir, the view of the Potomac, and the surrounding scenery, is one not often surpassed in beauty, and which will well repay those who have leisure to make it a visit.”

Alexandria never employed the wooden pipes — basically hollowed-out logs — that other communities, including Washington, had.

“Which was great,” Knepp said. “The people that put [the pipes] in said, ‘I don’t want wooden. I want something that’s going to last forever.’ ”

The oldest pipes currently in the Alexandria system were installed about 1885. They’re under the blocks of Peyton, Payne and Fairfax streets.

In 1929, Alexandria Water was acquired by American Waterworks and Electric, the precursor to today’s owner, Virginia American Water.

Alexandrians use 14 million gallons of water a day. The water comes from the utility’s sibling in Fairfax County, which draws it from two locations — the upper Potomac and the Occoquan. The water is treated before it comes to Alexandria — and after it leaves it, too.

In 1988, the reservoir site off Duke was designated a Water Landmark by the American Water Works Association, which is sort of like a lifetime achievement award Oscar.

Both reservoirs were originally open at the top. They were covered in 1979. The original reservoir — known as Duke Street #2 — has a brown polypropylene cover that rises and falls depending on the volume of water inside. The cover of the 14 million-gallon reservoir — Duke Street #1 — was removed after it was taken out of service. In the past 18 years, vegetation has grown in places in the basin.

Knepp said a study is underway to determine whether there’s anything that can go on the site of the disused reservoir. Answer Man thinks that with those angled walls, it would make a sweet velodrome, perfect for racers atop penny-farthing bicycles of the sort ridden when the reservoir was new.

Questions, please

Have a question about something you’ve seen in the Washington area? Send it to answerman@washpost.com.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/john-kelly.