The new TxDOT bridge will replace the existing truss bridge over the Colorado River in Columbus, Texas.  Stiver Engineering provided construction consulting to the bridge contractor with cofferdam designs for crane access on both banks of the Colorado River.  The cofferdams allowed the crane to get closer to the center of the proposed bridge so that the bridge beams could be lifted and installed.  The cofferdam was constructed using driven sheet piles, wales and cross ties.

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.

The purpose of the Luce Bayou Interbasin Transfer Project is to provide additional surface water supplies to end users that utilize water from Lake Houston.  Additional surface water supplies will be transferred from the Trinity River to Lake Houston via the Luce Bayou Interbasin Transfer Project to meet the increased demand for surface water.  There are currently no conveyance facilities to provide raw Trinity River water to the Northeast Water Purification Plant, which treats water from Lake Houston. The Northeast Water Purification Plant is vital in providing treated surface water to City of Houston customers  and previous studies have shown that Lake Houston and Northeast Water Purification Plant cannot meet future demands at their current capacity.  Transfer of additional raw water supplies to Lake Houston and future expansion of treatment capacity at the Northeast Water Purification Plant is required to allow for the mandatory conversion from groundwater to surface water. The Luce Bayou Interbasin Transfer Project will provide the additional raw water resources necessary to satisfy these demands. The City of Houston, Texas holds permits to divert raw water at a maximum rate of 775 cubic feet per second (approximately 500 million gallons per day) from the Capers Ridge site to Lake Houston.

The Luce Bayou Interbasin Transfer Project includes the Capers Ridge Pump Station located on the Trinity River in Liberty County, 3 miles of dual 96 inch diameter pipelines, and 23.5 miles of earthen canal system.  The pump station will be located on the Trinity River. The pipeline will extend west southwest approximately 3 miles along a geological ridge (Capers Ridge). The pipeline will then outfall into the sedimentation basin at the start of the canal. The canal will outfall into the lower reaches of Luce Bayou, which flows into the northeastern corner of Lake Houston.

Stiver Engineering was retained by the contractor to provide construction consulting through a cofferdam design for the construction of the Capers Ridge Pump Station.  Stiver Engineering also provided excavation plans for the installation of the proposed dual 96 inch diameter outlet piping.

This project specified the construction of two reinforced concrete boxes from Buffalo Bayou to San Felipe Road in Houston, Texas. The excavation was located a short distance from high-voltage power line towers and two main railroad lines. Stiver Engineering was hired to provide construction consulting through a braced shoring system that included sheet piles, wales, and a cross strut design that could be adjusted to accommodate construction.

One of our clients had to install a force main on a piles at a depth of 12-feet below Charleston Bay. The project is located on the South side of Plum Island in the Ashley River Basin in Charleston, South Carolina. Stiver Engineering was retained for construction consulting to design a shoring system for the installation of the force main to provide the contractor access to the site during low tide conditions. The shoring was designed with sheet piles, wales, and cross struts, enabling the contractor to drive an excavator and front-end loader on the wale set for access to the excavation and installation of the force main. The force main now connects the new lift station to the existing Plum Island wastewater treatment facility.