Mill Creek Drainage Relief Tunnel

The Mill Creek Drainage Relief Tunnel Project will provide drainage relief to the Mill Creek and Peaks Branch watersheds and the State Thomas area (also referred to as the Woodall Rodgers area) in Dallas, Texas. The Project involves the interception and diversion of the surface stormwater drainage from the upper portions of these watersheds into the proposed tunnel and conveyance of the intercepted stormwater to White Rock Creek.

The Project consists of more than 26,000 lf of tunnel in hard rock, at depths ranging from 100-150 vf. This project is utilizing a first of its kind dual-diameter (37’-7” and 32’-6”) Robbins TBM. This state-of-the-art machine has the capability to transition from the 37’-7” diameter to the 32’-6” diameter within the tunnel. The project will have seven shafts and will have a total volume of 160 million gallons, upon completion. The Mill Creek project is currently the largest water tunnel project under construction in North America.