Puget Sound Sub-basins
There have been various way to divide Puget Sound into various units over the years. Some boundaries are more distinct than others. Some methods mix political with oceanographic approaches--with political boundaries favoring a "land-centric" view that conflict with a "water-centric" view. There is no single system that seems to satisfy all needs. Instead of reporting all the different systems, this page is for describing the various intersections of these systems, knowing that different variations serve different purposes. Eventually we will shift to a spatial foundation, but for now we describe the sound in words. The PSNERP oceanic sub-basins are used to organize this information.
|Sub-Basin||Notes on Usage|
|San Juan||While this lumps the islands with the Whatcom mainland, it generally describes the influence of the Fraser river outflow, including the Nooksack Watershed and the Samish Watershed as well as the San Juan Islands. The greater San Juan basin includes San Juan County, Whatcom County, and part of Island County and Skagit County|
|Juan de Fuca Basin||The boundary between Juan de Fuca and San Juan is a line in the water. Typically Juan de Fuca includes Port Townsend, Discovery Bay and Sequim Bay ecosystems. Where Juan de Fuca ends and North Central begins is defined by the shallower more protected waters of Admiralty Inlet. This system is mostly Clallam County with the northern part of Jefferson County.|
|Whidbey Basin||While the northern extent of Whidbey is clearly marked by deception pass, the southern boundary with South Central is somewhat ambiguous, and marked by the Snohomish Delta. Island County has been frequently challenged by having their jurisdiction divided into three or four sub-basins, and so Whidbey Island is frequently defined as its own unit, reverting to the "land-centric" view for political continuity. Even if it excludes eastern Whidbey Island it still includes the large Skagit Watershed, Stillaguamish Watershed and Snohomish Watershed, The basin includes Skagit County, Snohomish County and Island County.|
|North Central Basin||The boundary between North and South Central is fairly ambiguous. There is a sill which generally marks the boundary between the central basin and Juan de Fuca. This area is commonly called Admiralty Inlet. This basin has no large watersheds, and is located between Jefferson County, Island County, and the northern tip of Kitsap County|
|South Central Basin||The South Central Basin is often divided into the metropolitan East Sound and the sub-urbanizing West Sound, given the difference in governance, development, and economic power. The urban shoreline includes south Snohomish County, King County, and Pierce County, while West Sound is mostly Kitsap County, with a little Pierce County in the south and King County having jurisdiction over Vashon-Maury Island.|
|Hood Canal Basin||Long skinny Hood canal has a distinct northern mouth and sill, and is consistently mapped as its own unit. Jefferson County lies to the west, Mason County to the South, and Kitsap County to the east.|
|South Puget Sound Basin||The Tacoma Narrows clearly defines the transition to the shallow South Puget Sound. T|
Other A category including the seven sub-basins used by the PSNERP study to divide Puget Sound and surrounding waters.
The following pages are flagged with the Sub-basin category: