^^^ Hah hah hah...
I was living here then. Yes, the Salt River was a mile wide or something like that. It cut the metropolitan Phoenix in half, and there were only 3 bridges left to connect the east and west parts. And unfortunately, I had to go cross town to get to work.
But some people blamed the problem on the Salt River Project, who managed the reservoir system on the Salt River watershed. I don't remember the details, but they said the SRP did not discharge the water gradually beforehand. They wanted to be sure that there would be enough water in the reservoirs for summer use. When heavy rain came, they had to discharge A LOT to make room, and hence the problem.
It was called the 100-Year Flood. I forgot to buy a T-shirt to commemorate this event.
Ever since, there was no water flowing in the Salt River, the part that goes through Phoenix. I repeat, none. Water was diverted from the lowest reservoir to go to the distribution channels. There was no spare water to let flow down the river bed, which has been bone dry for the last few decades.
Phoenix has grown so much since then, every drop was spoken for. There's little chance of water even getting wasted down the Salt River to recharge the aquifer under the desert soil, let alone causing a flood.
But if we had enough rain to cause a flood, a lot of people, myself included, will be dancin'. Bring on the rain, please.
This is true-the SRP system was built to capture and store water for later use. IIRC, there was also concern about the integrity of the dam at those highest water levels. After the floods in 78(?) and 1980, Roosevelt dam was enlarged/built higher, providing room for flood control as well as to storage.