Freshwater in the Salish Sea Bioregion

The Salish Sea Bioregion is defined by the watersheds that drain into the Salish Sea (you can learn about how the bioregion is defined in " Where is the Salish Sea? "). The rivers and streams in these watersheds connect their upland drainage areas to the marine waters of the Salish Sea. The Salish Sea is considered an estuarine system due to the large inputs of freshwater it receives throughout the year. Streams deliver freshwater along with sediments, nutrients, organic matter, and pollutants to the sea.

Watersheds are areas in which surface water flows to a common outlet such as a lake, sea, or ocean. The Salish Sea Bioregion's watersheds include several that are part of the greater Fraser River drainage basin, as well as others that are part of smaller coastal drainage areas that deliver freshwater directly to the Pacific Ocean and Salish Sea. The Cascade Mountains and Coast Mountains create a drainage divide that separates the Salish Sea drainage basin from the Columbia watershed. The map below shows the Salish Sea Bioregion's location in the context of major North American watersheds.

Seasonal stream flow patterns

Visit the  Salish Sea Atlas  website to access all of the atlas's data, chapters, and reference maps.

View data sources and processing details, or download the datasets used in this chapter of the  Salish Sea Atlas :

•  Salish Sea Bioregion Boundary 
•  Major rivers with monthly discharge 
•  Watersheds in the Salish Sea Bioregion 
•  Watersheds in the Salish Sea Bioregion and the entire Fraser River drainage basin 
•  Complete stream line network 
•  Lakes and reservoirs