Feeding a Hungry River

by Elizabeth Brink
Monday, December 15, 2008

The Sandy River in Oregon is undergoing a restoration since the Marmot Dam was removed.
The Sandy River in Oregon is undergoing a restoration since the Marmot Dam was removed.
When the nearly 50-foot-high Marmot Dam was removed from the Sandy River in Oregon last year, some estimated it could take two to five years for the river to process the rocks, gravel and sand that had collected in the reservoir for decades. Instead, the river cleaned itself out in months.

In fact, the day after the dam was removed, federally protected Coho salmon were migrating past the former dam site.

This summer, the Little Sandy Dam was also taken out, fulfilling a cooperative agreement between the Bureau of Land Management (BLM) and dam owner Portland General Electric (PGE) to remove the Bull Run Hydroelectric Project (which includes both dams) and restore the free-flowing character of the Sandy River.

The project was built in 1913 to power a trolley that carried city dwellers out to the countryside, but PGE decided in 1999 that the costs of modifying the dams to help declining fish runs were higher than their energy value.

The big question on Marmot Dam quickly became, should they attempt to remove the sediment behind the dam or simply blow it up and let it go.

They blew it up.

Before they did, the Fish and Wildlife Department converted its Sandy fish hatchery to raising only fish stocks native to the Sandy, rather than the more generic hatchery fish.

While Marmot Dam had a fish ladder, and therefore did not completely block migration of anadromous species, its removal does allow faster, easier fish access to 100 miles of river above the dam. The Little Sandy was only 16 feet high, but that was enough to completely block six miles of salmon stream.

Bill Bakke, executive director of the Native Fish Society, said one of the most important values of this project is that it "lays more groundwork for a lot more dam removals, which have value for our rivers."

Gordon Grant, a research hydrologist with the US Forest Service's Pacific Northwest Research Station, has documented the results of the Sandy River decommissioning project. Due to a strong global interest in dam removal, Grant recently returned from giving his Sandy River restoration talk at the newly formed Chinese Center for River Restoration, a presentation he has taken on the road across the US and to Europe.

Internationally, Grant has found that interested audiences are often surprised that we are taking down even fully functional dams in the US, and tend to assume that dam removal is motivated by a high economic value of fishing. Grant believes that the power of the US regulatory structure is what primarily paves the way for river restoration.

Though viewing the project through the lens of a scientist, Grant is quick to note "all restoration occurs within a cultural context." However, if you have a strong core scientific process, that can translate across cultural lines.