A Texas-Sized Endeavor (Source: Civil + Structural Engineer)

By Christine Kirby and Kevin Tran

Things are indeed bigger in Texas. And Houston’s Northeast Transmission Line is no exception. After a decade of astonishing 21.6 percent population growth, the Houston region is expected to double its current population by 2050. To keep up with projected water demands, and in response to the Harris-Galveston Subsidence District mandate to reduce groundwater pumping along the Texas coastal region, the City of Houston partnered with regional water authorities to build the Northeast Transmission Line (NETL).

The NETL program, Houston’s largest water transmission program yet, is full steam ahead. The project will convey 365 MGD of treated surface water from the newly expanded Northeast Water Purification Plant (NEWPP) through 16.5 miles of primarily 108-inch steel water line from Lake Houston to west of IH-45 with various take-points and interconnections along the way. The water line will also provide redundancy for areas serviced by the existing 66-inch waterline along the Greens Road corridor.

“Houston Public Works is integrating multiple segments into one massive pipeline. Once complete, the City will be able to increase surface water usage to help minimize subsidence and flooding,” said Panduranga P.K. Kuruva, P.E., managing engineer for Houston’s surface water program. “Increasing water capacity is vital to meet Houston’s growing demand.”

By the Numbers

Houston Public Works divided the 16.5 miles into 13 construction contracts. With most of the line being 108-inch diameter, the projects also included 120-inch, 96-inch, 84-inch, 66-inch, 54-inch and 42-inch diameter interconnections. All 16.5 miles of steel water line was manufactured in Texas factories with more than 21,700 metric tons of domestically sourced steel coil. The total construction cost is nearly $450 million, with 26 large diameter isolation valves, more than 17,000 linear feet of tunnels, and over 100 easement parcels. Once the Northeast Water Purification Plant (NEWPP) Expansion is completed, the NETL will serve more than 900,000 homes in Harris County.

“A project of this magnitude required years of planning and extensive collaboration,” said Mackrena Ramos, P.E., vice president at Lockwood, Andrews & Newnam, Inc. (LAN), a national planning, engineering and program management firm that is serving as the technical advisor. “Just the sheer size of the project makes it unique, but the number of individuals it took to make it a reality is quite amazing. From the City team to their partners, engineers, utility coordinators, manufacturers, and contractors’ workforce, we all had a vested interest to meet the water needs of Texans.”