City of Tacoma: $9M floodwall project on schedule, within budget

A $9 million project to build a floodwall around Tacoma’s Central Wastewater Treatment Plant is within budget and ahead of schedule, City of Tacoma officials announced Monday.

Construction is wrapping up on the project, which began last spring, with only landscaping and other minor work remaining. The project is being paid for using nearly $3 million in utility customer rates, as well as $6 million in Pierce County Flood Control Zone District funds.

“This flood protection project is key to our economic prosperity and public health,” said Tacoma City Councilmember Ryan Mello. “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. 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, according to City officials. 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, City officials report. In addition to the city, Tacoma’s Wastewater Treatment Plant serves customers in Fife, Fircrest and unincorporated Pierce County.

More information about the Central Wastewater Treatment Plant is available online at

Tacoma's Central Wastewater Treatment Plant. (PHOTO COURTESY CITY OF TACOMA)

Tacoma’s Central Wastewater Treatment Plant. (PHOTO COURTESY CITY OF TACOMA)

To read the Tacoma Daily Index’s complete and comprehensive coverage of the Central Wastewater Treatment Plant flood protection project, click on the following links: