Updated: July 31, 2019, 2:03 p.m. A second lawsuit against the proposed Oak Hill Parkway project was filed July 29, with plaintiffs including local groups Fix 290, Save Oak Hill, Save Barton Creek Association, South Windmill Run Neighborhood Association, Clean Water Action and some nearby landowners, according to a news release by the collection of groups. The lawsuit was filed against both the Texas Department of Transportation and the Capitol Area Metropolitan Planning Organization. According to the release, the lawsuit's goal is "not to stop the project, but rather to work with the Texas Department of Transportation to improve the project and avoid both litigation and construction caused delays." The suit outlines "several flaws" with the project's environmental review and challenges that TxDOT has made changes to original plans since environmental clearance was given in late 2018. Original post: July 30, 2019, 11:04 a.m. In a new hurdle for the proposed Oak Hill Parkway project, the Save Our Springs Alliance has filed a lawsuit against the Texas Department of Transportation—the project’s organizer—and the U.S. Fish & Wildlife Service. Save Our Springs Alliance claimed the proposed project at the Y at Oak Hill does not ensure it “will not jeopardize the survival of the Barton Springs salamander and the Austin blind salamander,” a violation of the Endangered Species Act, according to the lawsuit. The Oak Hill Parkway project is a 12-lane highway in Southwest Austin that aims to improve mobility near the intersection of Hwy. 290 and Hwy. 71. Plans for the non-tolled project include six new main lanes for through traffic on Hwy. 290. Proposed improvements also include an additional two to three frontage lanes in each direction, an overpass for Hwy. 290 at William Cannon Drive and flyovers between Hwy. 290 and Hwy. 71, according to TxDOT. The project received official environmental clearance in December and was added to the Capital Area Metropolitan Planning Organization’s 2019-22 Transportation Improvement Program in January. “In terms of environmental sensitivity, there couldn’t be a worse location for this amount of excavation,” the alliance’s senior staff attorney Kelly Davis said in a news release about the lawsuit. “The Recharge Zone is highly vulnerable to pollutants, such as silts and fuels, which can impact the underground water quality upon which the endangered salamanders depend.” Proponents of the project said Oak Hill Parkway would increase accessibility, make it easier to get around the Y at Oak Hill and help mitigate additional traffic growth in the area. CAMPO projects traffic volume at the already congested intersection will more than double by the year 2040, and local residents for years have asked for solutions. However, groups that oppose the project have become more vocal in recent months. On July 9, 14 local organizations—including the Save Our Springs Alliance, the Friendship Alliance, Save Oak Hill and the Austin Group of the Sierra Club—penned a letter to TxDOT asking for the project’s scope to be changed. In the letter, the organizations asked for TxDOT to consider a “grade-level freeway” that was “right-sized” and “protects Williamson Creek and the Barton Springs Edwards Aquifer.” Both the letter and lawsuit also support the “Livable Oak Hill plan,” an alternative created by local group Save Oak Hill that would have a smaller footprint and could save a number of heritage and legacy trees. The proposal shows a local access road on the northern side near Williamson Creek with a highway divided by a greenbelt trail.