The City of Austin is shifting its efforts from slope stabilization to flood risk reduction in response to the landslide along Shoal Creek. The landslide, which resulted from natural causes, took place on Friday, May 4, 2018. An additional movement took place on May 8, 2019.
The landslide deposited rock, soil and debris in the creek that has reduced its capacity to convey floodwaters. This partial blockage in the creek increases the chance of flooding on Lamar Blvd.
The City is in the planning stage for a project to restore some of the flood capacity of Shoal Creek and protect parkland from further erosion. This project does not include a slope stabilization component, but it helps address public safety issues that arose from the landslide. It focuses on reducing flood risk and protecting the creek and public infrastructure.
Last June, the City Council authorized negotiations with a contractor for the design and construction of a project that would have included a slope stabilization component as well as addressing flooding and drainage issues, the damaged park trail and wastewater pipe. A portion of the slope is located on private property. This project required the City to acquire easements from the property owners. The easements were needed for the contractor to install the slope stabilization system.
Negotiations with both the design-build contractor and the homeowners were unsuccessful. Negotiations for the design-build contract had to be suspended because of the contractor’s inability to obtain both the insurance normally required for this sort of project and additional insurance that the contractor wanted. The negotiations with the homeowners for the necessary easements were prolonged. The homeowners objected to certain restrictions that had to be placed on their property to ensure the integrity of the slope stabilization system.
After it became clear that the contractor was not going to enter into an agreement for the project, the City took the opportunity to reassess the various issues. The City reviewed our goals and priorities for addressing the public health and safety concerns, identified which goals were achievable, and put together a plan for the current project.
The current project will include removal of some of the debris from Shoal Creek and widening of the creek at certain locations. Next steps include finalizing the engineering analysis and drawing up construction plans. More information on the timeline and cost will be available this spring.
Two other projects will also be needed. There is a wastewater line in Shoal Creek that the landslide damaged. A temporary solution has already been put in place, but a permanent new wastewater line will need to be installed outside of the creek.
A segment of the Shoal Creek Greenbelt Trail will also need to be reconstructed. The trail has been detoured since the initial landslide.
More information is available at austintexas.gov/shoalcreeklandslide.