AUSTIN (KXAN) — Of the many places in Austin to take a swim this summer, Lady Bird Lake is not one of them. 

The lake, which is technically a reservoir, has been off-limits to swimmers since 1964 when Austin City Council banned swimming in what was then Town Lake, according to the city’s watershed protection department. 

The 1964 ordinance bans swimming between the Tom Miller Dam and the Old Montopolis Bridge in Colorado River waters.

Why did they ban swimming? Liz Johnston, the city’s deputy environmental officer in the Watershed Protection Department, said the ban began after several drownings on the Colorado River and the lake.

Pollution is not the primary reason and would not be a reason today to prohibit swimming, Johnston said.

“There are a lot of urban streams that flow into Lady Bird Lake, and so I can understand why people consider it to be polluted,” Johnston said.

The watershed department and state monitor Lady Bird Lake’s contact recreation standards, which look at E. coli levels. Johnston said the water does meet standards for stand-up paddleboards, kayaks and —technically — swimming. But other safety hazards are still reasons to keep swimming prohibited.

Prior sand mining operations, gravel mining operations and floods are some reasons why the river remains off-limits to swimming. There are also currents from Lower Colorado River Authority water releases that create a danger to swimmers. There are also destroyed bridges under water that could be treacherous.

Most of the lake is between 10 to 16 feet deep with some shallower and deeper areas, Johnston said.

The waters are closed to swimming, but paddleboarding, kayaking and other water activities are allowed.

While no rule prohibits dogs from swimming in the lake, Johnston said it is “swim at your own risk” and recommends dogs rinse off after. Harmful algae have been found in the water, which has killed some dogs in recent years.

“If there’s a lot of algae around, then it’s very possible that there could be toxic algae present,” Johnston said.

People should also rinse off if they make contact with the water, too.

“Enjoy your time on Lady Bird Lake,” Johnston said. “But…any body of water could have risks associated with it, and so just wash off afterward.”

Town Lake? Lady Bird Lake?

You might hear the dammed river that goes through Austin called a few names. Today, its official name is Lady Bird Lake, but it was once called Town Lake.

The lake was created in 1960 after the Longhorn Dam was built as a cooling pond for the now-defunct Holly Power Plant, according to the Texas Water Development Board.

Its name was changed in 2007 to honor the late Claudia Alta “Lady Bird” Johnson, who had recently died.