It seems to happen every few years -- a monsoon storm strong enough to flood a major Valley highway, stranding drivers and forcing a closure.
Last week, drivers on the US-60 became the latest victims as channels of water started rushing down the highway near Rural Road.
The Arizona Department of Transportation says the flood pumps simply got overwhelmed by the sheer volume of water in such a short time.
The explanation is that even the largest capacity pumps can still only handle so much water. ADOT says it can plan for a 10-year or 50-year flood event but there is no way to prepare for a 1,000-year flood event with four inches of rain falling in a matter of hours like the Valley saw last week.
The bad news is, the explanation means there’s always the possibility of a repeat if enough rain were to fall, but it’s a big “IF.”
The good news is ADOT is in the middle of replacing two aging pumps along US-60 with newer, more reliable ones at 48th and Val Vista. It’s a $3.5-million project that will have the new pumps in operation this fall.
Plans are already in the works to make similar upgrades along Interstate 17 at Greenway, Cactus and Thunderbird roads to prevent underpass flooding, which happens often during the monsoon.
In 2021, the pumps along Interstate 10 at the Deck Park tunnel will be overhauled.