What is Downstream?

The Skagit Environmental Endowment Commission focuses on Ross Dam, Ross Lake and Canadian region of the Upper Skagit watershed. When the Skagit River headwaters were threatened by a potential mine on Silverdaisy Mountain a few years ago, much was said about the potential downstream harms if an industrial accident would cause an unplanned release of mine tailings effluent into the Skagit.

Most Canadians are not familiar with Washington State’s geography. What exactly is downstream of Ross Dam or, to put it another way, beyond the lip of the dam so to speak? These are some of the towns and cities on the Skagit River’s route to the sea.

“The northern end of the basin extends 28 miles into Canada and covers 400 square miles. The headwaters of the Skagit arise in the steep Cascade Mountains of Canada and flow west and south into the United States. The river continues to flow through steep mountains for the next 40 miles where it passes through Ross, Diablo, and Gorge Dams owned by Seattle City Light above the town of Newhalem.

The river continues for approximately 70 miles through less precipitous mountain valleys

  • and the small towns of Marblemount (2000 population 251),
  • Concrete (2000 population 760), Hamilton (2000 population 309)
  • Lyman (2000 population 409) before emerging in the vicinity of
  • Sedro-Woolley (2000 population 8,658) (US Census Bureau 2010a).

The river then meanders for about 25 miles through the coastal lowlands between the cities of

  • Burlington (2000 population 6,757) and
  • Mount Vernon (2006-2008 population 30,745) before discharging into
  • Skagit Bay (US Census Bureau 2010a and b).

Population in the watershed is concentrated in the lowland delta area with only a few small towns in the upper basin (Sedro Woolley being the largest). Before it reaches the bay, the river crosses a broad outwash plain and divides into two principle branches, the north and south forks, which are 7.3 miles and
8.1 miles long, respectively, and which normally carry 60 percent and 40 percent of the flow, respectively. ”

Source Document: http://tinyurl.com/skagitcounty