Austin Unveils Design For A New Bridge On The Southern End Of Lady Bird Lake

Dec 10, 2019

The City of Austin is one step closer to taking down the “last major barrier” on the Hike and Bike Trail around Lady Bird Lake. And, according to city street designer Nathan Wilkes, the idea came from the public.

The barrier he’s talking about is on the Longhorn Dam, the structure that holds in the lake and provides its southernmost crossing. That’s where the 10-mile trail loop narrows into a 4-foot-wide sidewalk, and cyclists and pedestrians get hemmed in by a chain-link fence on one side and fear of a steep drop on the other.

“Right now the passing conditions are basically single file,” Wilkes said. “People squeeze up against the hand rail, which is very low.”

City planners have been looking for a solution to the bottleneck for years; the task gained urgency after the Lady Bird Lake boardwalk was completed and trail traffic increased.

Now, they think they could have the answer in the form of a proposed new bridge just upstream of the dam.

“It will look kind of similar to the Pfluger Bridge,” Katie Wettick, the urban trails program manager for Austin Public Works, said, referring to the pedestrian crossing farther north. “We do feel like the boardwalk was a big success, and so we would like to be able to ... sort of extend it with this safer connection.”

The city describes the proposal as a “wishbone” design; it also resembles a three-legged starfish. Three separate bridges connect to land on the North, South and Northwest shores, and meet at a central platform in the middle.

“We’re trying to create a kind of gathering spot there,” Wettick said. “People will both be moving through the bridge, but also at the center, where the three points meet, there will be … a place for people to spend time and enjoy the water.”

The bridge will be about 11 feet over the lake's normal water level.

Wilkes said the design was inspired by public input at a meeting the city held on the project about a year ago.

“At the first meeting, we asked people to sketch what their dream bridge would be, and this wishbone concept was actually a write-in,” he said. “About eight of the over 100 people who came to that first meeting drew this very similar meet-in-the-middle wishbone alignment.”

The concept eventually beat out four alternatives to become the city’s preferred option.

“It’s exciting,” Wilkes said. “If you go down your own path and you don’t even study the best possibilities, then you’ve already missed it.”

Not The Most Expensive; Not The Least

Wilkes said the city is finishing up a preliminary engineering study to determine an alignment for the bridge and “make sure we’re not hitting anything environmentally sensitive, that it’s structurally designable."

Staff will also look at ways to raise the $12.5 million the bridge is expected to cost. The bridge is “not the most expensive and it’s not the least expensive” of the options the city considered, Wilkes said.

He estimated the bridge will take five years to build once funding is secured.

Short-Term Fixes

In the meantime, the transportation department is planning to improve the current crossing at the Longhorn Dam.

The city has been looking for ways to ease congestion on the Pleasant Valley bridge over Lady Bird Lake.
Credit Gabriel C. Pérez / KUT

That will include raising the handrail along the lake, removing the barrier on the western sidewalk and widening the sidewalk from 4 to 8 feet.

Wilkes said the sidewalk on the eastern side of the bridge will also be widened and the city will put in crosswalks with pedestrian-activated crossing signals on either side of the bridge. These will help trail-users cross safely over Pleasant Valley Road, something that’s especially important when work is being down on the Longhorn Dam.

He expects that work to start midway through 2020.

Clarification This story has been amended to clarify the dam's engineering study is ongoing and that the pedestrian-activated signals along the dam will allow trail-users to cross at any point not just when workers are present.