Tim Esary gazed at lush vegetation along Burnt Bridge Creek in central Vancouver and remembered what the area looked like more than a decade ago.
“Just a field of reed grass,” said Esary, whose title is greenway sensitive lands supervisor for the city of Vancouver. “This was all blackberry, invasive species.”
After years of effort, reed canary grass and blackberries have been replaced by Oregon ash, crabapple, red alder, black cottonwood, Pacific willow and other native trees.
Esary, who started working on the Burnt Bridge Creek greenway in 2007, said more than a half million trees and shrubs have been planted in partnership with the Watershed Alliance of Southwest Washington and other community volunteers.
“It’s a great job,” he said. “Talk about rewards, being able to see what you have built over the years.”
The city is now looking to the west, to a section of Burnt Bridge Creek between Leverich Community Park and Northwest Lakeshore Avenue that is choked by reed canary grass.
Brian Potter, the city’s operations superintendent for grounds, stormwater and greenway sensitive lands, said the city is building partnerships with the Lower Columbia Estuary Partnership, the Washington State Department of Ecology and other organizations in preparation for transforming the western portion of Burnt Bridge Creek’s greenway.
“We have multiple projects that will plant upwards of 20,000 trees over the next two years,” Potter said.
For decades, Burnt Bridge Creek was little more than a polluted drainage ditch lined by invasive vegetation. The creek flows west for about 13 miles through the city, from its headwaters in east Vancouver, before emptying into a natural wetland near Northwest Lakeshore Avenue and flowing through two culverts into Vancouver Lake.
It has a history of pollution and contamination. In 1936, a child contracted typhoid from playing in its dirty waters. In 1958, the Clark County Health District declared Burnt Bridge Creek a threat to public health because of pollution from failing septic systems, deteriorating wooden sewer pipes and agricultural runoff.
For more than 20 years, Vancouver officials have worked to change that sorry legacy and create a greenway to treat polluted stormwater from roads, rooftops and parking lots not far from the creek’s banks.
By restoring the creek’s greenway, the city seeks to capitalize on nature’s ability to slow, store and filter polluted water. Planting trees, especially those on the creek’s south bank, provides shade and helps cool the water for fish and other aquatic life.
Esary said the city tries to plant native vegetation on both sides of the creek to create a true vegetation corridor to insulate the creek. The city primarily uses deciduous trees, he said, because their leaves and other material drop into the creek and feed macroinvertebrates, or water bugs, that in turn provide food for fish.
Besides enhancing water quality in Burnt Bridge Creek, the restoration also improves flood control and provides a multistory canopy for wildlife.
Vancouver has been able to merge urban recreation with environmental enhancement through the Burnt Bridge Creek Trail, which stretches for nearly 8 miles from Northwest Lakeshore Avenue near the mouth of Burnt Bridge Creek to Northeast 92nd Avenue. The paved trail is popular with walkers, runners, cyclists and others seeking exercise and a slice of nature in the middle of Washington’s fourth-biggest city.
The Washington State Noxious Weed Control Board describes reed canary grass as a major threat to natural wetlands. The species, native to Eurasia, grows to 6 feet and squeezes out other vegetation to create a monoculture that does little to improve water quality and wildlife habitat.
Potter said the city uses a type of Roundup to kill reed canary grass and other invasive species.
Bayer, parent company to Roundup’s manufacturer, faces more than 18,000 lawsuits in the U.S. from people who say the herbicide caused them to develop cancer.
Information is mixed on whether the herbicide is dangerous to humans. In February, researchers at the University of Washington said exposure to glyphosate, Roundup’s active ingredient, may increase the risk of non-Hodgkin lymphoma by as much as 41 percent. Two months later, the U.S. Environmental Protection Agency reaffirmed its previous conclusion that glyphosate is not a carcinogen and poses no risk to public health when used according to instructions.
Potter said city employees who use Roundup do so judiciously and in full compliance with instructions and regulations.
“All of our applicators are certified by the state,” he said.
The city uses Roundup to control reed canary grass and other invasive species because it’s much more efficient than removing it manually, Potter said.
“This is by far the most productive and efficient way to do it,” he said. “It’s done with the support and the approval of our environmental permitting bodies, Fish and Wildlife, Ecology and others.”
Esary said some vegetation can be controlled by first mowing and then spreading a thick layer of mulch over the remnants.
“You can’t do that with reed grass,” he said. “Reed grass will just come right back. It’s crazy.”
The city uses Roundup to kill reed canary grass and string trimmers to remove the dead vegetation before spreading mulch over the area. This fall and winter, the city and its partners and volunteers will plant new native trees.
“The little bit of chemicals we do use, the benefits definitely outweigh the negatives because we have a functional ecosystem,” Esary said.
Water quality results
Annette Griffy, Vancouver’s stormwater utility manager, said water testing continues to document elevated levels for temperature, bacteria and nutrients in Burnt Bridge Creek.
The city did not expect to see a swift recovery in water quality, Griffy said.
“The watershed has really been suffering over 150 years with urbanization,” she said. “It’s taken over 150 years for the creek to be degraded and to reverse that trend and [to] see improvements is not expected.”
So how does the city know it’s on the right track?
“We base our improvements on a lot of what is the science and a lot of what we will be required to do under the state requirements,” Griffy said.
Be First to Comment