DENVER (AP/CBS4) – Heavy rains over a short period of time have flooded some streets in Boulder.

The Boulder Daily Camera reports that more than an inch of rain over a 30-minute stretch Friday afternoon and overflowed creeks and flooded roadways.

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Boulder Creek in Lyons on Friday (credit: CBS)

Boulder Creek in Lyons on Friday (credit: CBS)

Weather conditions calmed in the city around 5 p.m., after the pounding rain prompted officials to evacuate the Boulder Municipal Building and the main library. Some bridges became impassible as well.

The National Weather Service had issued a flash flood watch from 10 a.m. to 8 p.m. for Boulder County, including the cities of Boulder and Longmont, and the Fourmile Fire burn scar in the foothills. A flood advisory was also issued for Lyons as minor flooding was expected along the St. Vrain River.

Tubing has been banned in both Boulder and Clear creeks because of the high water. But for professional kayaker Kalob Grady fresh rain on Boulder Creek was like fresh powder on the ski slopes.

“The river has been playing games with us all day. The level has been rising and dropping.

It’s the rapid rise and fall that has meteorologist and Flood Watch Network founder Greg Berman on alert.

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“That’s the highest it’s been since September,” Berman said.

Berman is worried about flooding and not knowing how rivers will react after last September’s flooding.

“The St. Vrain is now at 1,150 cfs. The old norm was 1,200,” he said. “We start worrying about flooding … our eyes have to be on the river for sure.”

Depending on how high and dangerous it gets, Lyons town officials say it could cancel events in the Outdoor Games Festival.

Berman encourages anyone living close to rivers or creeks and low-lying areas to start sandbagging now.

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