Public Works Engineering: Waller Creek Tunnel, Austin, TX


The Waller Creek Tunnel is a flood control tunnel that will be 22 feet in diameter and located in geologic formations including Austin (Buda) Limestone, Eagle Ford Shale and alluvium. The project study phase included extensive hydrologic and hydraulic modeling and design for the inlet and outlet structures.

The inlet structure design includes a 60-cfs recirculation pump station to maintain dry weather water quality in the tunnel and in Waller Creek. Flood water and recirculation water screening systems were also designed.  

The outlet structure includes a 30-cfs dewatering pump station and a recirculation screening system.  

For this $123 million construction project, Brown & Gay Engineers projected revenue cash flow and project cost over a 20-year project bond payback period and prepared updated detailed construction and engineering cost estimates in 2006. An updated 2006 financial analysis for 16 watershed build-out scenarios and three Tax Increment Finance District scenarios were also completed.