Flood in Maricopa County, Arizona

Widespread showers and embedded thunderstorms produced very heavy rainfall in Mesa during the morning hours on September 8th; peak rain rates were well in excess of 2 inches per hour and many locations received between 3 and 5 inches of rain with this event. The heavy rain led to significant urban flooding across Mesa, and one area that was especially hit hard was the Emerald Acres neighborhood located just north of US 60, and bounded by Stapley Drive and Harris. Water flowing towards the south ran up against a large berm protecting the Superstition freeway and had nowhere to go. A flood control canal bordering the freeway as well as several water retention basins were in place to protect against flooding; due to the excessive volume of runoff they were overwhelmed and as a result the neighborhood became flooded with one to three feet of water. Approximately 200 homes suffered significant flood damage and many residents had to be evacuated. Many of the homes suffered ruined flooring as well as damaged drywall that needed to be replaced. Crews started pumping water out of the area with large machines on Tuesday, September 9th and by early morning Wednesday, most of the water was removed from the streets in the Harris/Stapley neighborhood. It was estimated that water would not be completely removed for a week.

Showers and embedded thunderstorms developed across south central Arizona during the early morning hours on September 8th, and as the morning progressed the showers intensified and became more and more widespread. Partially due to an infusion of tropical moisture from former hurricane Norbert, the storms produced intense rainfall with rainfall rates commonly in excess of 2 inches per hour and in some cases, in excess of 6 inches per hour for short periods of time. By the middle of the morning, most of the central deserts had received over two inches of rain, and many locations across the greater Phoenix metropolitan area picked up between 3 and 6 inches of rainfall. Phoenix Sky Harbor airport received 3.29 inches of rainfall with this event; the rain total set an all time record for any calendar date. The rainfall caused widespread flash flooding followed by flooding; numerous roads were closed. Several freeways were closed, including Interstate 10, as pumping stations failed and lakes several feet deep formed across portions of the freeways. Hundreds of cars were stranded across the greater Phoenix area, many buried to the top of their hoods in flood waters. Hundreds of homes and apartment complexes across the greater Phoenix area were flooded. Heavy rains damaged roofs across the valley, and collapsed the roof of a Fry's grocery store in Tempe. Clearly, the heavy rainfall led to a historic flooding event across south central Arizona on September 8th.