I haven't been following it all that much, but it is on schedule. The tunnel itself and the outlet at the river are complete, but they're still working on the inlet at 4th Street, 8th Street and Waterloo Park.
http://www.austintexas.gov/departmen...r-creek-tunnel
The conservancy is still planning their public use upgrades along the creek and in the parks.
https://www.wallercreek.org/