Floodwall in Place at Tacoma’s Wastewater Treatment Plant

Tacoma’s Central Wastewater Treatment Plant is protected against a potential flooding event now that a floodwall is fully in place around the facility and in working order.

Construction, which started in spring 2014, is currently on budget and two months ahead of schedule, with only landscaping and other minor work remaining. The cost of this project was almost $9 million, with nearly $3 million covered in utility customer rates and $6 million in Pierce County Flood Control Zone District funds.

"This flood protection project is key to our economic prosperity and public health.  The work our city team and contractors did to bring this essential project in ahead of schedule and within budget is very positive for the region,” said Council Member Ryan Mello. “Our gratitude to the Flood Control Zone District for assisting with this project that benefits the entire region."

The 2,500 foot long wall stretches along the outside of the plant, ranges from one to eight feet high and extends 25 feet below ground. In addition to three manual gates, three hydrostatic lift gates were installed that will operate automatically during a flooding event.

During large storm events, the plant receives and treats more than 130 million gallons of wastewater a day before the treated wastewater is discharged to Commencement Bay. A major flooding event at the plant would destroy treatment equipment and would cause millions of gallons of untreated wastewater to overflow into Puget Sound with potentially negative impacts to businesses, wildlife and recreation. In addition to the city, Tacoma’s Wastewater Treatment Plant serves customers in Fife, Fircrest and unincorporated Pierce County.

For more information on the Central Wastewater Treatment Plant, visit cityoftacoma.org.