PHOENIX (3TV/CBS 5) - The same north Phoenix underpasses that usually flood during monsoon storms flooded again during Wednesday night's downpour, but local officials hope that'll change once a major construction job is finished.
A big drainage project is scheduled to start this fall and is expected to prevent flooding along Interstate 17 at Greenway, Thunderbird, Cactus, and Peoria roads.
First, the old pump stations will be be removed.
"Some of those pump stations, (we) can no longer get parts to replace them," said Chaun Hill with the Maricopa Association of Governments. It's the agency responsible for long-term transportation planning for the Valley.
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She said the pumps will be replaced with a gravity-fed storm drain system. Pipes 30 inches to 90 inches in diameter will move the stormwater to a canal system near Dunlap Avenue.
The construction job will take just under two years to complete.
"It'll be seamless once it's complete. But during construction, I think it'll be really interesting to watch the complexity of a project that's going to bury a 90-inch pipe in the ground," Hill said.
The project will also include two more retention basins at I-17 and Thunderbird.
"The system can just no longer keep up with (the rain)," said Hill. "Once the project is completed, it'll work like magic."
The whole construction job will cost $38.4 million. The money is coming from Proposition 400, a half-cent sales tax approved in 2004 for transportation projects in Maricopa County.