Salmon still run through the middle of Seattle. That they do at all, given what's been done to their river, is either a miracle or a lesson — and it's really the second one.
The Green-Duwamish is the urban extreme: a river whose lower reach was straightened, dredged, and poisoned into a federal Superfund site, and whose salmon persist mostly because people actively keep them there. It shows both how far degradation can go, and exactly what it takes to hold a run in place once it has.
The Lower Duwamish lost about 97% of its original salmon habitat — a 9-mile tidal estuary of marsh, mudflats, and meandering channels was reshaped into a roughly 5-mile industrial shipping channel.
That lower river is now a federal Superfund cleanup site — the juvenile salmon of an ESA-listed run have to transit a contaminated industrial waterway on their way to sea.
Howard Hanson Dam (1962) cut off the upper watershed and reduced spawning gravel in the middle river — degradation top and bottom, with the fish squeezed in between.
Here's the part that matters for the argument. A run this hemmed in — Superfund estuary below, dam above — is not persisting on its own. It's persisting because of active intervention. The Green is a major Chinook producer largely because of the Soos Creek Hatchery, whose output is much of what keeps adult fish coming back at all. And at the top of the watershed, the response to Howard Hanson wasn't demolition — it was engineered fish passage to reconnect habitat above the dam.
Left purely to "protect what's there and wait," a river reduced to an industrial channel would have very little left to protect. What keeps salmon in the middle of a major city is the same thing we argue for everywhere: active production, engineered passage, and habitat work, applied on purpose.
The Green-Duwamish is where the slow, ordinary version of loss — a channel dredged here, a wetland filled there, a contaminant discharged upstream — is followed all the way to its conclusion. It's a preview of where any urbanizing salmon river ends up if degradation is allowed to accumulate unchecked: a run that exists only because it's being actively held in place, in a river that's barely a river anymore.
The hopeful side is that even here, active recovery keeps salmon present — and a serious restoration effort is underway to give the estuary back some of what it lost. But the warning is the whole point: don't let a river get to this before you act. See the rest of the record, or get involved.
The Green-Duwamish is not a lost cause, and it would be wrong to write it off. Real restoration is underway — the Muckleshoot and Suquamish Tribes, King County, the cities, and the Army Corps are rebuilding estuary habitat and improving passage, and every acre reclaimed helps. Howard Hanson Dam also provides genuine flood protection for the valley below it, which is not a small thing.
The point isn't that the river is hopeless; it's that keeping salmon in a river this damaged takes constant, active effort — and the smarter path is to intervene long before any watershed reaches this state.
The figures on this page are drawn from public, authoritative records:
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