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River history

Looking back some 100 years, the Willamette River was a far different river. In those days, the river was not impeded by dams, leaving its natural current and flow to fluctuate with the seasons, from low summer flows, to massive floods that were nearly annual occurrences. These floods spread throughout the Willamette River bottomlands, extending across low-lying floodplain lands depositing rich sediment, and offering access for fish to key refuge and food sources.

In some areas, the river became miles wide with brown swirling water. It is not hard to imagine this dynamic river system, of interconnecting channels and still, quiet backwaters, interspersed with raging channels pushing through river rock and willows. Meandering channels, completely shaded by riparian vegetation, provided cool water refuges for migrating fish, away from the rush of the main channel.

This river of old has changed drastically. Today, dams control the river’s flow, and vast stretches of the riverside have been channelized. Old backchannels were cut off from the main river steadily from the mid 1800s onward, and riverside areas were rip-rapped—essentially coated with large rock—to keep the bank in place, thereby relegating the flow to one main channel in most areas. The river was dredged in spots, making it deep enough to support commercial river traffic, but destroying riverbeds and river habitat in the process.

Over the past few decades, the river has been simplified, cutting off side channels and floodplain areas, and curbing its natural spring flows. Today, in places, one can get a sense of the natural river, especially in those areas where the river moves and deposits its gravel bars. In these areas, one may find cool water being transported from upland areas or percolating through gravel beds providing essential habitat for native fish. This kind of natural river action provides a sense of what is needed throughout the Willamette River.

In combination with the transformation of natural habitat, the river’s once clean waters have been polluted over time as well.

 

 


Willamette Falls Locks

 

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