Arizona Department of Transportation

“The new system is designed to be much more efficient in handling any of the storm water that’s being directed toward those underpasses,” said Doug Nintzel, a spokesperson with the Arizona Department of Transportation.

Just in time for monsoon season, the state Department of Transportation says it has completed a $38 million drainage system along part of Interstate 17 in north Phoenix.

Doug Nintzel with ADOT said the new system has been under construction since the spring of 2020.

“The new system is designed to be much more efficient in handling any of the storm water that’s being directed toward those underpasses,” Nintzel said.

Water tends to pool in underpasses and other low lying areas. The new system, Ninztel said, uses gravity to direct that water into an underground pipeline and then to a diversion channel.

“It’s all about angling of the pipelines as they’re underground to be able to keep the water moving in a drainage system,” Nintzel said, “combined with the fact that we have two new stormwater retention basins.”

It replaces several pump stations from 1964 that would get overwhelmed during heavy rainfall, leading to pooling at some underpasses. Nintzel said the 50 or so pump stations on other Valley freeways can still be used if needed.

And the new system, which has opened in stages, has already seen a few storms.

“The system was holding up very well when those storms were occurring, say in the past year or so,” Nintzel said.

But he still warns drivers to abide by the old mantra: “Turn around, don’t drown.”