The Filter Building at White Rock Lake. Photography by Shelby Tauber.

It was April 1914. White Rock Lake was filled with 6 billion gallons of water, and the pump station was providing water to nearby residents. 

No filtration plant existed at the lake, but the water was treated at a plant in Turtle Creek. 

In 1915, Dr. W.R. Blaylock wrote a letter to The Dallas Morning News, warning that the lake could become a petri dish for typhoid and other germs if recreational activities were allowed there. 

Water Commissioner A.C. Cason suggested that residents should boil water because it could “become foul at any time,” even though it was being filtered by the Turtle Creek plant. 

An analysis in 1916 revealed the White Rock water, which was treated with chlorine, was free of disease-causing bacteria. But the state sanitation engineer, V.M. Ehlers, recommended that a filtration plant be constructed by the lake. The lake’s watershed included land inhabited by thousands of people, whom Ehlers described as “renters who cannot be expected to keep their premises in a sanitary condition,” in addition to the farms, cemeteries, railroads and highways nearby. 

By February 1917, the lake water was still considered sterile because of the chlorine, but it had a bad odor. Months later, the City Health Board ruled that the water was “unfit for domestic use.”

Three years later, typhoid fever broke out in Dallas, and White Rock Lake water was determined to be one of the causes. The pump station had broken down, and water was introduced into the main supply without being filtered, just treated with chlorine. 

The City asked engineer David Morey to investigate the water supply, and he recommended that aeration, sedimentation, filtration through rapid sand filters and chlorination be implemented. An engineering professor at the University of Texas agreed. 

So in 1921, construction of a filtration plant at White Rock began. Morey undertook the design with help from three engineers. Plans called for a castle-like building made of the same red brick that distinguished the nearby pump station.

It would have a low-lift pumping station and aerator, a mixing channel, two sedimentation basins, a coagulation basin, 12 rapid filters, a filtered-water reservoir and a wash water tank. Dallas-based Hughes-O’Rourke Construction Co. built the facility, which cost $381,000. 

Inside the Filter Building at White Rock Lake. Photography by Shelby Tauber.

Here’s how The Dallas Morning News described the filtration process in 1923: 

“The ‘raw’ water is brought into a small concrete tank, where it picks up a specific quantity of hydrated lime and alum, or compound of iron. It is then run into the 6,000,000-gallon sediment basins, where the lime and alum or iron settles, taking the impurities with them. The water is clear at this stage of almost all impurities. From the sediment basin it is run into the filter tanks, where it seeps through layers of sand and gravel into the pipes that carry it to the clear-water basin, from which it is forced into the city mains.”

White Rock Lake’s status as a water source ended with the completion of Lake Dallas in Denton County in 1930. 

The Filter Building wasn’t torn down, even though it wasn’t being used anymore. Woodrow Wilson students used to sneak into the basement and graffiti it. 

In 2008, White Rock Boathouse, Inc. renovated the building into an event venue. 

Source: “From Water Supply to ‘Urban Oasis’: A History of White rock Lake Park, Dallas, Texas (2022)‘” by Steven R. Butler