For the first time this decade, Chinook are spawning in a Seattle stream, and what’s more they’re doing so in a stretch restored for just that purpose.
Seattle Public Utilities reports that in late October it spotted the pair in Thornton Creek’s Meadowbrook reach, between Matthews Beach on Lake Washington and Nathan Hale High School.
That section was part of an $8 million 2014 SPU project that combined improved spawning habitat with better flood control.
“We engineered the streambed vertically and horizontally. Four years after construction, it is maintaining very high-quality gravel,” said utility biologist Katherine Lynch in a press release. “The Chinook salmon pair travelled almost one and a half miles to select this site for spawning. That’s a vote of confidence!”
Ironically, Thornton isn’t even among the sites the public are directed to go to for Salmon Seeson in King County, but the duo appear to be fin-clipped, and in its release SPU noted the importance of the salmon stock to starving southern resident killer whales.
Thornton here formerly was a 1,000-foot-long ditch, essentially a “hallway” for fish instead of a home, and above there it still runs nearly as straight as an arrow.
As my two young sons can tell you, if last Sunday’s visit to Seattle’s Pipers Creek and a chat with a fish steward there is any indication, in addition to clear, clean and cold water, salmon need connected and complex streams– the 5Cs.
The Meadowbrook work also includes a pond that fills with runoff during high water events, filtering out some of the debris.
Well upstream, my family and I had a rain garden installed outside our house to slow and treat street runoff that feeds into a stormwater drain that dumps into Thornton. It’s suspected that particles from tires flushed off the roads into urban waterways are particularly deadly to returning adult coho and their young.
In a year of mixed news for Northwest salmon, that a pair of Chinook found themselves in a city stream outfitted with spawning gravel is a bit of good.