The Mill Creek Drainage Relief Tunnel is a construction project that will bring needed infrastructure improvement to east Dallas, Texas. Stiver Engineering provided construction consulting services for the contractor prior to and during the tunnel construction.

The tunnel, which stretches from the State-Thomas District in Uptown Dallas, through Mill Creek and Peaks Branch, will be constructed mostly underground with little impact to neighborhoods. Once complete, the approximately five mile-long tunnel will sit 70 to 100 feet below ground to provide flood relief.

The Mill Creek Drainage Relief Tunnel is a five-mile underground tunnel that will provide 100-year flood protection for nearly 6,000 commercial and residential properties in the east Dallas area, including Baylor Medical Center. The current drainage system in these areas was constructed 50 to 70 years ago, and only provides a two to five year flood protection. Major flooding that occurred in 1995, 2003, 2006 and 2009 crippled these areas and showed dire need for the construction of this drainage relief tunnel. The Mill Creek/Peaks Branch/State-Thomas Drainage Relief Tunnel will improve stormwater management resulting in saved lives, protection of schools, medical facilities, residents and streets. Construction began in spring 2018 and is slated for completion in 2023. The tunnel is being constructed by Southland Mole Joint Venture. Prior to construction beginning, a tunnel-boring machine (TBM) will be constructed on site. By using a TBM, there will be minimal utility relocation, as well as minimal street and traffic impacts. Once complete, the tunnel will be approximately 30 feet in diameter, and will be designed to carry a maximum flow of nine million gallons per minute. This provides exponential relief of flooding during large rain events. The tunnel will have six intake sites along the alignment. These include:

  • Woodall Rodgers Intake – Intersection of Woodall Rodgers Freeway and Maple-Routh Connection
  • Mill Creek Intake – Intersection of San Jacinto Street and Apple Street
  • Peaks Branch Intake – Intersection of North Carroll Avenue and Victor Street
  • Peaks Branch 2 Intake – Intersection of E R L Thornton Freeway (I-30) and South Hill Avenue
  • East Peaks Branch Intake – Intersection of Bank Street and Herndon Drive
  • Outfall – White Rock Creek at Barber Avenue

 

The City of Houston’s Northeast Water Purification Plant (NEWPP) Expansion Project is a design-build project that will add 320 million gallons per day (mgd) by 2024 to the existing water plant’s capacity. The expansion project will allow the City and the regional water authorities to meet projected demands, while fulfilling requirements set by the Harris-Galveston and Fort Bend Subsidence Districts resulting in a shift from historical groundwater usage to a predominant reliance on surface water.

​Construction on the $1.7 billion project started in early 2018 and has been called the largest expansion project in the world. The NEWPP expansion is required to comply with subsidence district rules for conversion from groundwater to surface water supply, resulting in a reduction of the subsidence rate.  Features of the project include the design, construction and commissioning of:

  • Intake pump station
  • Twin 108-inch transmission mains
  • Pre- and post-treatment chemical addition
  • Flocculation/sedimentation basins
  • Ozone treatment
  • Filtration
  • Finished water storage tanks
  • High service pumping station

Stiver Engineering provided construction consulting through the following designs for contractors working on the NEWPP Project:

  • Shoring design for 10,200 LF of twin 108-in.-dia. raw water transmission mains in common trench at a depth of 18 ft. to 40 ft.
  • Pipe buoyancy calculations for the 38,000 CY of controlled low strength material (CLSM) backfill.
  • Entry shaft, exit shaft and tunnel design for the 360-LF, 132-in.-dia. tunnel using liner plate.
  • Shoring design for the filter/transfer pump station.