Cross-border flood reduction plan to aid B.C., American communities not expected for two years

The status update report from Washington State noted that Indigenous knowledge, as well as geological and archeological evidence, indicate that the mainstem Nooksack River flowed through what is now the Sumas Prairie and into the Fraser River as recently as several hundred years ago.

“The reason that we have this really weird river and flooding problem now is still a remnant of the peculiar topography left by the ice sheet as it retreated at the end of the last Ice Age,” says Allison Pfeiffer, a Western Washington University associate professor of geology.