New I-17 drainage system in place at underpasses in north Phoenix

PHOENIX — A new Interstate 17 drainage system designed to reduce flooding in the underpasses between Peoria Avenue and Greenway Road in Phoenix is ready to operate, Arizona DOT announced.

The construction of the $38 million system was done by the Maricopa Association of Governments, the Valley’s metropolitan planning organization.

Crews installed pipelines and large storm retention basins for the system near Thunderbird Road, according to a press release.

The NEW regional drainage system designed to reduce the risk of stormwater flooding in underpasses along I-17 in Phoenix is ready to go.

The new system allowed ADOT to remove outdated pump stations from 1964 near lower-lying underpasses

MORE: https://t.co/NXfvuIaCGd pic.twitter.com/rVf9C7KAl1

— Arizona DOT (@ArizonaDOT) July 3, 2023

The new system will allow ADOT to remove old pump stations that were installed in 1964 near underpasses carrying Peoria Avenue and Cactus, Thunderbird and Greenway roads beneath I-17. The underpasses have been areas of heavy flooding after rain.

Work on the system began in 2020 including extensive trench work as well as tunneling under I-17 for pipeline installation. The water will drain into retention basins or the Arizona Canal Diversion Channel north of Dunlap Avenue.

ADOT reminds drivers that despite the new system, monsoon storms can bring heavy rain over a short period of time and can be taxing on any drain system, meaning drivers should always proceed with caution.

The improvement was a part of the Regional Transportation Plan for the Maricopa County region which is majority funded by Proposition 400.