PORTLAND, Ore. (KOIN) — Portland is known for having some of the best drinking water in the nation and a historic project at Washington Park is designed to keep it that way.
Work on the Washington Park Reservoir Improvement Project began in 2016 with the goal of upgrading uncovered reservoirs more than 100 years old to meet modern seismic standards and to ensure a secure water system.
Traces of a contaminant called cryptosporidium have been detected since 2017 so the federal government held to its mandate that Portland’s reservoirs be covered or buried.
“It is one of the most complicated projects that anyone in the construction industry — the engineering industry — will work on,” said Portland Water Bureau engineer Thomas Gilman. “The facilities that were here were really old and they were aging and it was time to replace time.”
But people living near Washington Park wanted the historic nature of the open reservoirs preserved.
To meet their expectations, Reservoir 3 will undergo some drastic changes. When the project is finished, a reflecting pool, water features and a promenade will sit on top of a 12.4-million-gallon underground reservoir.
The reservoir will store ready-to-drink water from the Bull Run Watershed, serving some 360,000 customers.
“It’s really important that for all of Portland for generations to come is that we’re going to have safe, secure drinking water,” Gilman said.
The $205-million project is also designed to withstand a major earthquake that scientists say is overdue.
Reservoir 3 will not be taken out of service. When the project is done it will be reconnected to the water system.
“Not only are we building a seismically-resilient structure but we also are contending with an ancient active landslide that we’re actually standing on right now,” said Gilman.
A second, lower reservoir at Washington Park — Reservoir 4 — will be disconnected from the water system and turned into a stormwater and filtration facility.
The Washington Park Reservoir Improvement Project is being paid for with revenue bonds backed by ratepayers. It’s expected to be done by 2025.
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