Sandy River (Oregon)
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The Sandy River is a tributary of the Columbia River, approximately 50 mi (80 km) long, in northwestern Oregon in the United States.
It rises in the Cascades in eastern Clackamas County, issuing from the Reid Glacier on the flanks of Mount Hood (the nearby Sandy Glacier drains into Muddy Fork, a tributary to the Sandy River). It is joined by the Zigzag River and Salmon River and then flows northwest past Sandy and Troutdale and joins the Columbia from the south in central Multnomah County, approximately 14 mi (23 km) east of Portland, near the lower end of the Columbia River Gorge. Flow rate averages from 700 to 3,000 ft³/s, with extremes from 45 to 84,400 ft³/s.
Tributaries of the Sandy River include the Bull Run River, Cedar Creek near the town of Sandy, Alder Creek, Wildcat Creek and Beaver Creek. The Sandy River provides drinking water via the Bull Run Reservoir for the Portland Metropolitan area. The Sandy River Fish Hatchery lies on Cedar Creek very near to its confluence with the Sandy.
The river is one of the few declared navigable rivers in Oregon. Because of this, public use is permitted from the line of high water mark and below. The most notable parks on the Sandy River (going upstream) Glenn Otto Park, Lewis and Clark State Recreation Site (boat ramp), Dabney State Recreation Area (boat ramp + parking fees), Oxbow Park (boat ramp + parking fees) and Dodge Park.
[edit] Hydroelectric decommissioning
Currently, the river is dammed and the flow rate is regulated, with a goal of at least 600 ft³/s of water continuously. The Bull Run Hydroelectric Project diverts water from the Sandy river at the Marmot Dam to the Little Sandy River at the Little Sandy Dam. Water is then diverted to Roslyn Lake through a wood box flume. The artificial lake supplies the 22-megawatt Bull Run hydroelectric powerhouse and empties into the Bull Run River (Oregon).
In 2007 the Marmot dam will be removed, followed by the Little Sandy Dam in 2008. Roslyn Lake will then cease to exist. The decommissioning will restore the Little Sandy River to steelhead and salmon runs for the first time in a hundred years. Portland General Electric, the dams owner, will also donate 1500 acres of land near the dams to a nature reserve.
[edit] Historical note
Lewis and Clark wrote more pages on the Sandy River than any other tributary of the Columbia.
"... I arrived at the entrance of a river which appeared to Scatter over a Sand bar, the bottom of which I could See quite across and did not appear to be 4 Inches deep in any part; I attempted to wade this Stream and to my astonishment found the bottom a quick Sand, and impassable ..." [Clark, November 3, 1805]
The nearby Mount Hood had erupted a few years earlier, causing loose sediment to collect at the mouth. Although even today, the river sand can sink your leg in to the knee in some areas.