DENVER — Fifty years ago Tuesday, days of torrential rain that deluged Colorado caused the unthinkable. It changed the landscape of Denver and many other places in Colorado.
The South Platte River flooded through the heart of Denver, taking out homes, bridges and practically everything in its path.
The 1965 South Platte River Flood was Denver’s greatest disaster and changed the way flood control is dealt with.
“There was just so much water, it didn’t have nowhere to go. So it went over the banks,” said Jim Weber of unincorporated Adams County.
He was just 17 years old when the river hungrily swallowed the land around it as he watched from a bridge over the raging waters near his home in Ruby Hill.
“We stood three, four hours watching houses, debris, all kinds of stuff crash into the bridge,” he said.
The water had come from the south, near Larkspur, where it had rained 14 inches in just four hours, creating a 20-foot wall of water that raced from Plum Creek near Castle Rock into the South Platte and straight into Denver.
The water level on the South Platte is at about 14 feet. But in June 1965, it was more than double that, at 28 feet.
That amount of water today would cover Elitch Gardens, Pepsi Center, Sports Authority Field at Mile High and parts of Interstate 25.
The river spread 1 1/2 miles wide in some places. The South Platte also flowed at a rate that’s still a record.
“The flow right now in the river is 1,600 cubic feet per second. The day of the flood, in 1965, the flow was 110,000 cubic feet per second, about 50 times what we see in the river today,” U.S. Geological Survey hydrologist Suzanne Pashke said.
She said that flow today equates to filling one Olympic-sized swimming pool in one minute. Then, it filled 72 pools over the same time.
There was little anyone could do in 1965 to prevent the disaster that killed 21, destroyed or damaged more than 1,200 homes and displaced 1,400 families. But times have changed.
“We’ve seen a lot of advancement in our tools over the last 50 years. Satellite. Radar has been upgraded. Gauges, we have more of those. They go up to satellite. We get them in real time,” Robert Glancy with the National Weather Service said.
The flood led to long-term changes in flood control, including constructing Chatfield Dam to store water. There are also improved early-warning systems thanks in part to stream gauges to measure the depth and speed of water.
“It’s something not likely to see happen again, that’s for sure,” Weber said. “But it was an interesting experience. Once in a lifetime is enough.”
It’s science and technology that eases his mind. The flood caused $543 million in damage, which adjusted for inflation would be more than $4 billion in today’s dollars.