EVERETT — A large shopping mall at the southwest corner of 128th Street SW and Fourth Avenue W, just west of I-5, looks a little different now from how it looked about 30 years ago.
“In 1980, it was a forested wetland,” said Tom Murdoch, director of the Adopt-a-Stream Foundation.
While this type of change is commonplace, Murdoch mentions this because the wetland once was the headwaters for a creek.
Now, Puget Creek originates in the mall’s parking lot.
The stream runs dry in the summer and is a torrent in
the winter, filled with rainwater rushing off of parking lots, rooftops and roads.
Similar scenarios have played out around other parts of Snohomish County and the Puget Sound area, resulting in loss of spawning habitat for salmon and other fish, he said.
People for Puget Sound, a Seattle-based non-profit group working to reduce pollution in the Sound, sponsored an event with Adopt-a-Stream last week at McCollum Park in south Everett to highlight the issue.
Adopt-a-Stream, a non-profit group based in McCollum Park, promotes stream habitat restoration and preservation and carries out many such projects on its own.
Presenters at the event provided an overview of the issues in a classroom and then Murdoch led a group of 17 people on a walk along North Creek, which runs through McCollum Park.
While development can’t be stopped, new types of more environmentally friendly development, when added up, can make a big difference, participants said.
Buildings can be built with “green roofs,” on which vegetation is actually planted. Water can be funneled from downspouts into rain barrels or rain gardens — areas landscaped with native plants designed to absorb moisture. New types of porous surfaces can be used on playgrounds and driveways, letting water percolate down into the soil instead of running straight off into streams, carrying pollutants with it.
Rain gardens, while effective, can also be expensive. Stacy Aleksich, low-impact development specialist for the Snohomish Conservation District, said small rain gardens can be created for $500, while larger ones can run up to $5,000.
Still, just planting some trees can help, she said.
“Everything we put on our ground matters,” she said.
When too much water rushes into streams, it causes several problems at once, experts say. These include washing pollutants such as mercury and petroleum hydrocarbons into the water, raising water temperature and washing out spawning gravel — all bad conditions for fish, Murdoch said.
Ideally, native plants and overhanging trees extend about 300 feet from each side of a stream, providing shade and filtering the water, Murdoch said.
In a natural Northwest environment, only about one-quarter of all rainfall reaches streams, said Suzi Wong Swint, a watershed education coordinator for the Snohomish County department of surface water management.
“Our world is designed to get water out of our way as quickly as possible, so we’re not drowning in puddles,” she said.
In an area with a lot of pavement and rooftops, nearly all of it gets in, she said.
In the 1980s, development accelerated to the point where local governments started having to manage stormwater runoff with measures such as retention ponds, Swint said.
Prior to 1988, Snohomish County’s stormwater department did not exist, she said.
“The water just kind of managed itself,” Swint said.
Now the county and most other local jurisdictions charge a fee for stormwater management. Owners of single-family homes in unincorporated Snohomish County pay $122 per year if they’re inside an urban growth area or $90 outside.
Development has had a profound effect on North Creek and its 30-square-mile watershed, which runs from Everett Mall Way to Lake Washington, Murdoch said.
That watershed is now nearly half covered with rooftops and pavement, he said.
Chinook, coho and sockeye salmon, steelhead, cutthroat trout, sculpin, dace and brook lamprey all once spawned in great numbers in the creek, according to Murdoch.
In the late 1970s, “the salmon were so thick in McCollum Park you could walk across their backs,” he said. “Now you’re lucky if you see two or three.”
Measures taken on North Creek seem to have slightly improved the numbers for trout and brook lamprey, he said. Adopt-a-Stream made improvements to the stream environment, converted a parking lot into a wetland and has re-routed runoff from the McCollum Park buildings and pavement into that wetland instead of the stream.
Also, the city of Everett pumps water from underground wells into the creek during dry periods, according to Murdoch.
“Little actions like that, you start adding them up and they can turn things around,” he said.
Bill Sheets: 425-339-3439; firstname.lastname@example.org.