PHOENIX, AZ — A flood warning in metro Phoenix has been extended through the Halloween weekend as heavy runoff keeps parts of Maricopa County under threat. The National Weather Service said flooding from excessive rainfall is continuing in south central Arizona, with low-water crossings and low-lying areas already affected in some spots.
The warning includes the Salt River corridor and Indian Bend Wash, where water levels have been high enough to prompt repeated updates through Saturday and into Monday morning. Meteorologists urged drivers to stay away from flooded roads, especially at night, when standing water can be harder to see.
Salt River flooding remains a concern below Granite Reef Dam
One of the main trouble spots is the Salt River below Granite Reef Dam, where the weather service said flooding was imminent or already happening. The warning also covers crossings upstream of Tempe Town Lake, including McKellips Road, which may become impassable when water rises.
At 2:45 p.m., Salt River Project was releasing 1,650 cubic feet per second from Granite Reef Dam. Earlier in the day, SRP had been releasing 3,800 cfs, a sign that flows in the area had already been high enough to keep flood impacts active across the river corridor.
The weather service said some locations between Granite Reef Dam and Tempe Town Lake could see flooding. Officials also said remaining road closures should be heeded while water keeps moving through the system.
Indian Bend Wash and nearby neighborhoods stay under flood threat
The National Weather Service also warned that Indian Bend Wash remained flooded or close to flooding, with low-water crossings covered by water and possibly unsafe to cross. Stream gauges showed water levels above alarm stage after runoff from earlier heavy rain pushed through the drainage system.
The affected area includes parts of Paradise Valley and Scottsdale. Meteorologists said 1 to 3 inches of rain had already fallen in the watershed, and that it could take several hours for water to move through urban drainage systems.
Even though no additional rainfall was expected in that warning area, flooding impacts were expected to continue. That means conditions can stay dangerous long after the heaviest rain has moved on.
Rio Verde and Fort McDowell included in the later warning update
Later updates widened the concern to additional parts of Maricopa County, including Rio Verde and Fort McDowell. The weather service said flooding caused by excessive rainfall was expected until 8 a.m. Monday, with rivers, creeks, streams and other flood-prone places at risk.
At 2:41 p.m., gauge reports indicated heavy rain effects from releases upstream from Bartlett Dam, and the weather service said flooding was already occurring in the warned area. Streams were still rising as runoff from earlier rainfall continued to work through the system.
The warning message described flooding as imminent or occurring in several low-lying areas, underscoring that the danger was not limited to one neighborhood or one roadway. In practical terms, that means conditions can change quickly from passable to hazardous.
National Weather Service urges drivers to avoid flooded roads
Along with the warning itself, meteorologists repeated standard flood-safety advice for the region. Their message was simple: turn around, don’t drown. They cautioned that most flood deaths happen in vehicles and that darkness makes it harder to judge how deep water really is.
The weather service also warned that just 6 inches of moving water can knock a person off their feet, while 12 inches can carry away smaller vehicles. SUVs and trucks are not immune either; 2 feet of water can sweep them away.
Residents were told to avoid walking through floodwater, pay attention to road closures, and keep children away from flowing water. The agency also warned that floodwaters can hide rocks, trees and other debris beneath the surface.
How long the warning lasts and what comes next
The warning was first issued on Saturday, Oct. 31, and later extended through the weekend into Monday morning, depending on the part of the county being watched. One update said the Flood Warning would expire at 4 p.m. Saturday, while a later one reissued the warning through 8 a.m. Monday.
That shifting timeline reflects how quickly conditions can change after heavy rainfall and dam releases feed the same drainage network. The weather service said water was still moving through the Salt River system and local urban drainage channels, which means flooding can linger even after rain stops.
For metro Phoenix drivers and residents, the key takeaway is to keep checking closures and weather alerts. In a flood event like this, the most dangerous roads are often the ones that look shallow until a vehicle reaches them.