Union River - WRIA 15.0503

The Union watershed is 24 square miles with 10 miles mainstem and 30 miles of tributaries. The stream originates on the south and eastern sides of Gold Mountain. It flows through managed but undeveloped forest area to Union River Reservoir (City of Bremerton water supply) which is held by the Cascade dam. The stream flows down McKenna Falls (beginning of natural barrier) through low gradient broad mixed coniferous/deciduous floodplain to estuarine delta of Hood Canal. A unique characteristic of the Union River floodplain is the natural abundance of Belfast soil type (USDA Soil Survey for Mason County) consisting of silt and sandy loam. This is important when considering the type of riparian vegetation 54 (predominantly red cedar, maple and willow) and gravel characteristics that naturally occur along the low gradient portion of the river.

Stock Status: See salmon distribution maps, stock charts, and documents (right side of screen).
Federally listed (threatened) – HC/ESJF summer chum spawning and rearing (healthy in 2002 SaSI); Puget Sound Chinook salmon rearing and spawning (but not identified as a stock in 2002 SaSI)
Healthy – coho, fall/late fall chum (2002 SaSI)
Unknown - winter steelhead (2002 SaSI)
NOTE: Chinook supplementation project has been discontinued; summer chum supplementation on-going, 2000 to present.

Land Use: Managed forest in the upper portions of the watershed (above the reservoir), water storage and diversion, some residential development, hobby farms, tree farms, gravel pits, retired commercial land fill, WDFW wildlife recreation area, warehouse and open storage area.

Factors for Decline: bridge constrictions (several); floodplain constriction by levees, residential development, hobby farms; bank hardening; riparian lacks conifer for LWD recruitment; summer low flows; elevated water temps; livestock; failing septic systems; estuarine impacts.

For all references and an expanded version of this description see the Hood Canal Coordinating Council’s Habitat Recovery Strategy for the Hood Canal and Eastern Strait of Juan de Fuca, version 09-2005