W-2 Transmission Line Project

Following a mandate to reduce groundwater usage by 30%, the San Jacinto River Authority developed its Groundwater Reduction Plan, which includes treating surface water from Lake Conroe and distributing it through a network of pipelines to areas in The Woodlands, the I-45 corridor, and the City of Conroe. Schnabel performed a feasibility study and geotechnical investigation trenchless design services for the project.

The W-2 Water Transmission Line Project is part of The Woodlands pipeline and consists of approximately 34,000 feet of 30-inch and 42-inch waterlines along the southbound right-of-way from South Millbend Drive to Green Bridge Drive. Along the proposed alignment, the waterline will cross numerous existing roads, utilities, and waterways. The soils generally consist of clayey sand, silty sand, poorly graded sand, sandy lean clay, lean clay, fat clay, and sandy fat clay soils extending to depths of about 30–50 feet. The pipeline will mainly be installed by open-cut excavation except at 28 key crossings where trenchless excavations are proposed.

We performed site reconnaissance of the undercrossings, reviewed the available geotechnical information, recommended appropriate trenchless construction methods, and aided the preparation of the preliminary report. During final design, we developed the required trenchless plans and specifications. During construction, we reviewed contractor submittals related to the tunneling and supported the construction management team with review and validation of contractor-proposed alternatives for several crossings.