Updated Monday, November 5, 2012 at 11:31 PM
A beaver dam built across a pond near Duvall broke apart on Monday, unleashing a torrent of water, mud and debris that damaged a home and flooded a street.
The dam broke apart around 11 a.m., and water from a 3- to 4-acre pond traveled down a natural watershed, forcing road closures near a roundabout at Northeast 124th Street and state Highway 203, said Lynne Miller, spokeswoman for the King County Office of Emergency Management.
No injuries were reported.
"I had a wall of water 4 to 5 feet high, 160 feet wide up behind my house, around both sides of my house," said Bob Siko, whose home was damaged by the floodwaters.
Sharon Conn, who lives near the pond, said the floodwaters "pretty well washed out" Northeast 124th Street, where she lives.
"It's just like a raging river, and right now they're not letting anyone out," she said by phone as water poured down the street. "It was just this small, little area here; we're kind of isolated. There's no other road out."
A section of Northeast 124th Street was closed from 12 to 1:30 p.m. because of the ruptured beaver dam, according to a King County Department of Transportation alert.
Siko said his house received only minor damage but that there was extensive damage to his property, which was covered in sand and silt.
He said he does not have flood insurance because his property is not located in a flood plain.
Siko said he took his concerns about the beaver dam to King County earlier this year. He said he was told the U.S. Army Corps of Engineers would look into it, but he never heard from that agency.
"I've been concerned. I feel the county did what they were supposed to and they notified the proper authorities. I just don't know where they (the Corps of Engineers) were with the assessment," Siko said.
Miller said she was unaware of Siko's conversations with county officials. She said King County did not previously consider the beaver dam "an issue."
The Conns were aware of the dam but hadn't worried about a collapse causing damage.
"It was no big deal to us," Sharon Conn said.
Brian Calkins, the small-game manager at the state Department of Fish and Wildlife, said the "massive failure of a beaver dam is not a common experience."
"If you get a heavy rainfall they are commonly washed away, but not to the degree that it would cause the flooding of a home," he said.
In April 2009, a breached dam built by a family of beavers sent a 10-foot cascade of water, trees and debris crashing through a beachfront community in Clinton, Island County. Eight homes were hit, and one was left tilting after tons of water pushed it from its foundation.
Fish and Wildlife officials regularly hear from local residents seeking advice on how to deal with beaver dams. Officials will advise them or ask them to contact state-licensed "nuisance wildlife operators."
"They trap and remove, typically, nuisance animals. Sometimes they give people advice, but we do, too," Calkins said, adding that beaver dams are common in Western Washington.
According to the Department of Fish and Wildlife's website, beavers live in colonies ranging from two to 12 animals. A colony usually is made up of the adult breeding pair; the offspring, or kits, from that year; and kits of the previous year or years.
It's unclear how many beavers were living on the pond where Monday's flood let loose.
Beavers flood areas for protection from predators, for access to their food supply and to create an underwater entrance to their den. Beaver dams are generally built using wood, stones, mud and plant parts, according to Fish and Wildlife.
Fish and Wildlife officials say that beavers often allow their dams to leak, especially when the water level is high.
Seattle Times staff reporter Steve Miletich and news researcher Miyoko Wolf contributed to this report.
Jennifer Sullivan: 206-464-8294 or email@example.com. On Twitter @SeattleSullivan.
MARK HARRISON / THE SEATTLE TIMES
Muddy water washes over a roadway near Duvall on Monday after a beaver dam gave way, spilling a rush of water and debris from a large pond downhill through a natural drainage. Roads were closed and at least one home was damaged.
MARK HARRISON / THE SEATTLE TIMES
Family members, friends and neighbors help dig out Bob Siko's home Monday. Siko raised concerns about the dam and had been waiting for a response from the Army Corps of Engineers.