City of Austin

(Austin) Austin Mayor Lee Leffingwell, Councilman Mike Martinez, Austin Water Director Greg Meszaros and Public Works Director Howard Lazarus will mark the end of one of the largest and most complex wastewater infrastructure projects built by the Utility over the last decade. The ribbon cutting will take place at 1:30 p.m. on Tuesday, October 30, at the corner of Riverside Drive and First Street. Parking will be available in the Long Center service yard. Video of the actual underground tunnel will be provided on DVD.

The new four-mile long wastewater tunnel crosses under Lady Bird Lake three times from the Seaholm Power Plant to South Pleasant Valley Road near Kreig Field in southeast Austin. The tunnel will serve downtown and parts of south Austin, transporting wastewater to Austin Water plants for treatment.

This project is a response to residential and business growth in the City's downtown corridor. Two major sewer lines in downtown Austin on the north and south shores of Lady Bird Lake were near capacity and had limited ability to take additional sewer flows. The new wastewater tunnel is now taking sewer flows from both the existing lines to provide the additional capacity needed for existing and future growth in central Austin.

The tunnel replaces aging infrastructure installed more than 50 years ago. Engineers designed the new tunnel using state-of-the-art materials like resin instead of traditional concrete to extend the longevity of the system. The bulk of the work was done up to 80 feet underground using the latest in tunneling technology. The new wastewater infrastructure is expected to last 100 years—twice as long as the old system.

In addition to added capacity, the tunnel construction allowed Austin Water to decommission two lift stations reducing energy consumption and maintenance cost, while freeing up downtown land for other uses including the new central library and more parks.