The lower-river number alone is already large
The U.S. Army Corps of Engineers says the Columbia River channel and adjacent lower Willamette move roughly 51.6 million tons of cargo a year with an annual cargo value of about $16 billion.
That means a closure of the lower route is not a niche inconvenience. If you divide that annual cargo value by 365 to get a scale estimate, you get roughly $44 million a day in freight value moving through that corridor. That is not the same thing as direct final loss, but it is a reasonable way to show the size of the traffic that would be caught in delay if the route shut down.
If disruption spread beyond the lower river, the number gets bigger
A Corps planning record says the wider Columbia-Snake River Navigation System moves over 50 million tons of cargo worth about $24 billion annually.
Using the same simple scale estimate, that works out to about $66 million a day in freight value. Again, that is a value-in-motion estimate, not a claim that every delayed dollar becomes permanent damage. But it does show why a spill or shutdown on the lower Columbia can quickly become a regional freight problem, not just a local one.
Washington already says spills can halt commerce
Washington Ecology's oil-spill pages say spills can halt commerce, damage natural resources, close fisheries, and trigger expensive cleanup. That matters because the Columbia is not only a habitat system and not only a drinking-water system. It is also a working freight corridor.
So if people ask what a spill could cost, the clean answer is this: the public record supports saying the cargo value put into delay could land in the tens of millions of dollars per day, even before you start counting cleanup, fisheries, port disruption, or other knock-on costs.
Port Westward makes the shipping question part of this review
The Corps says the NEXT Renewable Fuels project could involve up to 171 ocean-going vessel movements a year through the existing Port of Columbia dock. That means the river-traffic question is already built into the federal review, not something critics invented later.
That is why the Port Westward story is about more than wetlands alone. If a project adds industrial throughput and vessel traffic to a shared interstate river corridor, the shipping-risk story belongs in the public record too.
What this estimate does and does not mean
I am not claiming a one-day closure automatically destroys $44 million or $66 million in final economic value. Some cargo would be delayed, some might reroute, and the exact loss would depend on timing, duration, contracts, commodities, and response conditions.
What I am claiming is narrower and source-backed: the Corps' own annual cargo values show that a serious shipping interruption on this corridor would put freight worth tens of millions of dollars per day into delay, which is enough to make spill risk a real economic issue, not just an environmental talking point.
