Spokane, Washington’s storm water tank may cost an additional $2 million.
The $2 million gallon storm water tank that has rerouted traffic behind the Spokane Library in Washington state for more than two years will be completed summer 2021.
This could cost utility ratepayers $2 million more than initially planned, according to the Spokesman-Review. The Spokane City Council approved a request that brought the full price of the tank to $33.3 million.
“We weren’t at 100% design. It was an estimate,” said Marlene Feist, city spokeswoman. “When we finally put in all the elements, it was more.”
The tank off of Spokane Falls Boulevard is the last structure slated for completion in a five year construction project, reported the Spokesman-Review. When the system is finished, it will capture millions of gallons of storm water.
The initiative aims to build the tanks in areas of the city’s water system where sewer and storm water runoff combine to run to the treatment plant, reported the Spokesman-Review.
The largest portion of funding is coming from the sale of “green bonds” in 2014, which raised $200 million for both the storm water tanks and new treatment membrane technology at the Riverside Park Water Reclamation Facility, which will be operational in 2021.
The bonds are being repaid with a portion of the bill collected from the city’s utility ratepayers, according to the Spokesman-Review. The rates for water, sewer and trash services are set to increase 2.9% next year.
The tank behind the library is capable of holding 2.2 million gallons of water. The other downtown tank did not present the same issues as the one near City Hall, reported the Spokesman-Review.
A briefing paper to the City Council noted incomplete or inaccurate mapping of pipes and wires beneath Lincoln Street. The ties used to ensure the tank would not tumble down the hill had to be made redundant, which added another $663,000 onto the project.
The tank behind the library will remain offline until crews can hook piping to it, according to the Spokesman-Review. Workers will wait until the dry months to hook it because it requires a sewer bypass.
There will continue to be untreated outflows into the Spokane River in the downtown area during the winter and spring months.