John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Following recent downpours, the South Platte River swelled so big that it consumed part of a city.
Greeley is a medium-sized city located about 50 miles north of Denver on the banks of the South Platte River. That's during a normal week. In recent days, Greeley has actually been located partly within the South Platte River, thanks to record-setting rains that fattened the waterway into obscene proportions.
The transformation of Greeley from bucolic meat-packing burg into Splashtown Water Park was captured, as so many things are nowadays, by the mechanical eye of a U.S. satellite. Here's what the Landsat 8 probe observed on June 29 (larger version):
Now look at the South Platte River this Tuesday, after huge amounts of rain sent water cascading down the Rockies into lower-level tributaries (larger):
The tributary has spilled over its banks seemingly everywhere, swamping farms and the southeastern part of the city with bubbling, coffee-colored water. Notice at top right how a new branch of the river has lurched and flowed into several fields just north of Highway 34. Travel southwest and it gets much worse, with sediment-loaded water ballooning unimpeded around the barely visible outline of the original Platte.
NASA adds some background on this historical drenching:
The image shows that the flood has washed away roads, including sections of U.S. Highway 34. Farmland and a few developed areas are under water. Heavy rain caused flooding across the Front Range of the Rocky Mountains starting on September 11, and much of that water made its way into the South Platte River. The river reached a record 18.79 feet in the early morning hours of September 14. The previous record crest was 11.73 feet. Flood stage is 10 feet. As the water subsides in Colorado, it is expected to swell the river downstream in Nebraska.
Here's a closer look at the neighborhood that was eclipsed by floodwater:
On a drier day it looked like this:
Colorado is in the middle of its wettest year in 120 years of record-keeping. That's partially a boon to the state's farmers, as it has helped diminish a drought that's been in place for a long time. In Greeley, though, these recent floods have actually forced the waterways to shift locations. That means the river-side apparatuses they rely on to gather water for irrigation are now useless, potentially allowing their crops to wither and die next year. As one local put it to the local Tribune, “How do you begin to deal with things like that?"