July 12, 2001
Bear Creek roars again
By CLAUDIA CORNISH and VICTORIA TOBIN
WSDOT Northwest Region
The steady rumble of state Route 520 traffic can be heard in the background. A casual glance reveals commercial development slowly encroaching, with many new stores already built and more on the way. But take a closer, quieter look behind the bustle and you will be rewarded with a small living snapshot of nature despite the noise and concrete — geese swimming in newly-formed pools, dragonflies darting from one spot to another and tiny dogwood and willow seedlings sprouting along a stream.
Wildlife has not only returned, but is flourishing in a stream that had been degraded by agricultural use and population growth.
The Bear Creek enhancement project used an evolutionary approach to stream bioengineering to relocate, reshape and restore a neglected agricultural ditch into a thriving ecosystem. The project was the result of four years of planning between King County, the city of Redmond, Redmond Town Center, Washington State Department of Transportation (WSDOT), Entranco and many other public agencies, private partners and committed community members.
Entranco’s Dale Anderson said the project illustrates the enormous effort needed to repair streams damaged many years ago by unenlightened property owners. That damage included bank erosion and instability, lack of appropriate vegetation and an inhospitable fish environment.
Consider some facts about this project. WSDOT’s cost for relocating and restoring this 1,700-foot section of stream nears $2.5 million. The complete restoration has occurred over three stages.
WSDOT NW Region’s Corey Wight said that both Phase 1 and 2 landscape areas, which are in a five-year plant establishment period, are thriving. Redmond Town Center is currently constructing the continuation of the adjacent city trail to the Sammamish River and should be finished soon. Also, the U.S. Army Corps of Engineers has plans to extend restoration efforts beyond the project limits downstream to the Lake Sammamish River.
The goals of the project were to build a stream that would not change course over time, as a natural stream would, and to further protect businesses and nearby Route 520 from water damage in case of flooding.
A big construction challenge was to not adversely affect water quality of the existing stream while building the new one. Tests on construction water runoff were routinely performed and three on-site treatment tanks purified water that was found to be too full of particulates. To protect vegetation, fish and other wildlife, careful coordination during construction prevented erosion.
The attention to detail put into this stream is staggering.
The new stream bed is lined with large Douglas fir stumps and root balls to establish fish rearing, resting and hiding places, and to help protect the stream bank from flood waters. Gravel replaces sand along the bank to encourage spawning, which is particularly important since this section of river serves as an entry point for all fish migrating to and from the Bear Creek Basin found upstream.
“Habitat snags,” large dead trees, were installed on the flood plain to provide perches that encourage birds to nest in the area. Several beavers were relocated to other bodies of water to reduce damage to native cottonwoods and other vegetation growing along the stream.
When crews opened the new stream channel to a full water flow last July, numerous fish and about 400 freshwater mussels were hand-transported from the old waterway into their new home.The diversity of life seen in the area includes deer, beaver, otters, herons, ducks, geese, garter snakes, frogs, butterflies and numerous varieties of insects. Salmon were spotted spawning in the new channelized portion of the creek last fall.
Aside from helping the environment, relocating the stream away from Route 520 clears the way for WSDOT to construct a long-awaited ramp to connect westbound state Route 202 to westbound Route 520. So in the long run motorists also will benefit from this stream relocation — without even realizing it.
But wildlife is already better off. So the next time you drive over 520 near Redmond, think about the meandering stream and flourishing ecosystem that is not only a snapshot of natural beauty today but the big picture in environmental preservation tomorrow.
Claudia Cornish, a 10-year WSDOT veteran, is the agency’s Northwest Region spokesperson. Victoria Tobin has more than a decade of experience in communications and recently joined WSDOT Northwest Region’s public information team.
Copyright ©2009 Seattle Daily Journal and DJC.COM.
Comments? Questions? Contact us.