Single beaver behind broken dam that flooded Glendale
April 9, 2009 · Updated 5:43 PM
Go easy on the Glendale beaver. He was just doing his job.
Actually, he wasn’t doing his job, and that’s the problem.
The beaver blamed for last week’s Glendale flood may have been dead for weeks, apparently run over while waddling across Cultus Bay Road.
The result was an unfortunate chain of events: a deteriorating and breached beaver dam, a rapidly rising creek, an overwhelmed and washed-out road and the Glendale Flood of 2009.
That’s the scenario pieced together by Friends of Glendale, a group of property owners who have monitored the wetlands complex along Glendale Creek since 2003.
“We’re trying to prevent beaver backlash,” said Craig Williams of Clinton, president of Friends of Glendale. “If they’re not around to maintain their dams, the dams can be easily compromised.”
“We’re not trying to minimize what happened, because it’s a tragedy,” Williams added. “We’re encouraging everyone to help however they can.”
“But beavers are a natural phenomenon and have an important role to play in our ecosystem,” he said.
A broken beaver dam has been blamed for the unexpected swelling of Glendale Creek on Thursday, April 2.
The next morning, the rising water wiped out a section of Glendale Road and the culvert under it and sent a wall of water, mud and debris rushing a mile down the canyon into the Glendale beach community.
About 10 homes were damaged. Residents had been evacuated hours earlier, and there were no reported injuries. But they’re still cleaning up the mess, and damage is expected to be in the millions of dollars.
Williams said Friends of Glendale is a loose association of about 40 to 50 households near Glendale Creek.
He said the group’s purpose is to keep tabs on the large wetlands complex near Cultus Bay and French roads, and to establish lines of communication between property owners in the area.
Williams said it has been well-documented that beavers have been active in the Glendale Creek watershed and other areas of South Whidbey since the 1900s.
Beavers build dams to protect against predators, such as coyotes, wolves and bears, and to provide easy access to food during winter.
They always work at night, carrying mud and stones with their fore-paws and timber between their teeth.
Beavers like to eat water-lily that grows at the bottom of lakes and rivers, along with the bark from birch, poplar and willow trees, and summer berries.
Williams said there had been no beaver activity near the creek since the 1990s, until this particular animal arrived last fall and started building a simple earthen dam.
Then, several weeks ago, a beaver was reported dead along Cultus Bay Road. Friends of Glendale believe it was the same one, since activity at the dam ceased thereafter, Williams said.
Before he was finished, however, the beaver, working alone, had built and maintained a dam about 50 feet wide. He also had plugged up the 24-inch culvert upstream under Frog Water Road, Williams said.
The result, in only a few months, was a pond complex several feethigher than before, containing 90- to 100 acre-feet of water, Williams said.
One acre-foot of water is about 380,000 gallons. Williams said that when about a third of the dam failed, the escaping water popped the plug on the Frog Water Road culvert, increasing the already-growing flow.
“It’s a cyclical natural event,” he said. “A beaver builds a dam, water collects behind it, the beaver is killed or his food source runs out and he moves on, there’s no more maintenance of the dam, the dam fails and the water pours out.”
Williams has lived on Whidbey since the l980s, and at his present location near Cultus Bay and French roads since 1997. He is a partner in a local technology consulting firm.
He and others in the area believe the Glendale flood wave occurred because the smaller culvert under Glendale Road near Holst Road about three miles downstream from the dam wasn’t designed to withstand such a high volume of water.
He said the flood, as devastating as it was to Glendale residents, may have a silver lining, because the road can now be rebuilt in such a way that it will serve both residents and nature.
“It’s a safety issue, a fish-passage issue and a wildlife issue,” Williams said.
He said a large box culvert or even a bridge at the washed-out section of Glendale Road may be the best solution.
Spawning salmon could travel farther upstream, and a Glendale Creek swollen by natural events such as snow, heavy rain and broken beaver dams could be handled without catastrophe, he said.
County officials have said all options will be considered before the road is rebuilt.
However, Bill Oakes, Island County Public Works director, said last week that the question of beaver dams is another matter entirely.
“Beaver dams on private property is an issue that needs to be addressed,” Oakes said. He said he’s talked with other counties, including King County, “and they tell very similar stories.”
He said the state Department of Fish and Wildlife should take a more active role in regulating beaver dams to avoid more incidents of flooding.
But Williams said he thinks intervention is only asking for trouble.
“If a landowner kills a beaver, the dam is likely to collapse,” he said.
The better course, he said, is to plan for “an extraordinary water event as well as a normal water event.”
Williams also said that the tons of water that washed down the creek flushed the canyon and replenished it with nutrients that will eventually benefit fish and wildlife.
He said the activity of beavers is especially important here because the impoundment of water helps to recharge Whidbey’s aquifers.
“A beaver in the system is both a positive and negative thing,” he said. “But it’s definitely a benefit for those of us who live on an island.”