City of Austin Downtown Tunnel
Austin, Texas

Arizpe was sub-contracted by Parsons to provide construction inspection services for underground tunnel related construction, construction phase engineering services and to monitor work for compliance with the contract documents.

The City of Austin is constructing a major tunnel wastewater interceptor that crosses central Austin, generally west to east. The tunnel interceptor will restore capacity to existing downtown area wastewater collectors and allow the Shoal Creek Lift Station and the Toomey Lift Station to be decommissioned. The tunnel interceptor will be approximately 3.5 miles long, with an excavated diameter of approximately 10 feet, and with finished diameters of 54 and 90 inches respectively. The interceptor sewer will discharge to the existing Govalle Tunnel, which transfers wastewater to the South Austin Regional Wastewater Treatment Plant. The project also includes the construction of 5 permanent manhole structures (80’ to 100’ deep) to provide access to the tunnel interceptor, as well as work to divert flows from existing sewers to the tunnel interceptor. The project has a 30 month construction schedule.

During design Arizpe provided traffic engineering services preparing contractor traffic routing patterns and Traffic Control construction documents for each of the boring shaft sites as part for the Tunnel Design Team. Arizpe also prepared a study for Odor Control requirements of the tunnel and met with City officials to determine the necessary strategies to control odor both during and after construction of the tunnel.