The Willamette River changes as it flows from south to north - fast and braided in the upper reach, slow and meandering in the middle, wide and tidally influenced as it approaches the Columbia River. Each reach has its own character and set of challenges.
On maps, the Willamette River begins just south of Eugene. But the river’s true headwaters lie in the watersheds of the Coast Fork, Middle Fork, and McKenzie rivers. The McKenzie and Middle Fork are especially important to the upper Willamette. Fed by melting snow that emerges from porous volcanic rock in the high Cascades, they provide clean drinking water to Eugene and Springfield and help moderate water temperatures in this reach. Warmer winters and predicted lower snowpacks threaten this natural cooling system.
Managing floods and flows
Dams located on upper Willamette tributaries provide many benefits—reduced flood damage downstream, improved summer flows, electricity, and reservoir-based recreation. At the same time, they alter water temperatures and natural flow patterns, reduce and simplify habitat, and block fish access to more than 400 miles of spawning streams, threatening the survival of salmon and steelhead populations. Federal and state agencies are working to address these issues, but solutions are expensive and will take many years to implement.
Habitats worth saving
The upper Willamette contains side channels, sloughs, and islands created by powerful currents that shape the river channel and surrounding floodplain. Water flowing beneath the river periodically resurfaces to create coldwater refuges for temperature-sensitive fish like salmon and trout. Over the past 150 years, these critically important habitats have been significantly reduced through flood management, erosion control projects, and urban and agricultural development.
One river, many uses
The Willamette River floodplain—the flat land directly adjacent to the river—contains highly productive farmland and many of Oregon’s largest cities. Naturally occurring gravel deposits, a valuable source of building material, are also critical for salmon habitat and water quality. Finding a balance between river health and the needs of important economic sectors is challenging everywhere along the Willamette, but especially here in the middle reach, where all play a prominent role in the area’s quality of life.
The temperature story
The middle Willamette received the poorest temperature score. Historically, cold tributary inflows and the movement of water through gravel bars and floodplain soils moderated the summer river temperatures. Today, these features have been greatly reduced, while warm water sources—from reservoirs, municipal and industrial discharges, paved surface run-off, and removal of vegetation that shades the river—have increased. Remaining areas of cold water have become havens for temperature-sensitive fish like trout and salmon.
Vanishing floodplain forests
Forests of cottonwood, alder, cedar, willow and fir once covered much of the Willamette River floodplain. Vital contributors to river health, these forests absorb floodwaters, remove sediments and pollution, reduce water temperatures, and provide important food and shelter for many species of fish and wildlife. Some of the best remaining examples of mature floodplain forest are found in the middle Willamette, but they occupy less than half their original footprint.
More people, more connections
Human connections to the Willamette multiply in the lower reach. Wilsonville and Sherwood draw their drinking water from the river and other communities have plans to do the same. The tribal lamprey harvest at Willamette Falls is one of the most important in the Columbia Basin. Fishing boats are a common sight in downtown Portland, and many people walk, jog, and bike along riverside paths. Throughout the lower Willamette, people flock to the river on sunny summer weekends.
The working river
Sand and gravel operations, pulp mills, and other commercial and industrial activities dot the length of the Willamette, but the river has a distinctly industrial feel moving through Portland. Dry docks, port terminals, and manufacturing facilities line the banks. Fishing boats and kayaks share the river with barges and cargo vessels. In 2000, the lower 11 miles of the river were designated a federal Superfund site, and authorities warn against eating resident fish more than once a month due to toxic contamination.
Within our reach
Approaching its confluence with the Columbia, the Willamette still carries water from far-off tributaries like the McKenzie and Santiam. It also carries the sediments, contaminants, and run-off of upstream cities, farms, and industrial facilities —but not as much as it once did. Significant and successful efforts have been made to improve the health of the river, by everyone from governors to a legion of dedicated volunteers. As a result, the Willamette is relatively healthy overall, deserving of our care and attention.