Poudre river peaks late, on July 1

After several crests in June, the Cache la Poudre River finally peaked on July 1. This year’s peak flow at the canyon mouth was 4,160 cubic feet per second. LaPorte did not flood this year, and residents began removing sandbags from their properties as the river settled down.

River commissioner George Varra said this year’s heavy runoff, caused by record mountain snowpack, was kind to riverbank residents because of the nature of the snowpack. “It was a real hard, dense snowpack,” he commented. “It acted like an ice cube and took a long time to melt.”

A July peak is highly unusual on the Poudre, where the average high point occurs on June 11. The only others on record, according to Varra, were the July 3 peak in 1975, a July 5 peak in 1909 and another on July 1 in 1904.

June saw several days when the river was running hard at 3,300 cfs or more.
Since the river was high for a long period, the total water volume during June was well above average, nearly 160,000 acre-feet as measured at the canyon mouth.

By contrast, the peak in 2010 was higher, 4,770 cfs, but total June volume was just 129,000 acre-feet last year.

The big flood year of 1983, when the Poudre stayed high until mid-July, dwarfed this year’s figures. The peak that year was 6,590 cfs, and June volume was a whopping 292,500 acre-feet of water.