Green Cove Creek

Green Cove Creek

The Green Cove Creek watershed is the largest watershed on Cooper Point. Lying northwest of downtown Olympia, it covers 2,626 acres (or 4.1 square miles) which drain to Eld Inlet at Green Cove. It is designated an environmentally sensitive area, as it is largely covered by critical area wetlands and highly sensitive aquifer areas. The basin includes Green Cove Creek and the Grass Lake wetlands, both of which are relatively intact.


Green Cove Creek

Green Cove Creek is a perennial stream, originating in the wetlands. Because it is comparatively pristine, the creek is among Olympia’s priority areas for salmon habitat protection measures. Green Cove Creek is critical habitat for Puget Sound Steelhead, which are Endangered Species Act-listed. The creek supports many other salmonid species, including Chinook, chum, coho, and cutthroat trout, all of which are listed by the federal government as threatened.


Unfortunately the salmon run is compromised until Thurston County fixes the compromised culvert at Country Club Road permanently, which is scheduled for completion by 2024. 


The surrounding forests provide habitat for beaver, Pacific tree frog, red frog, Townsend’s big-eared bat, bald eagle, great horned owl, and many more. Among the species that call Green Cove Creek home is the Olympic mudminnow, which the state recognizes as “sensitive”, meaning vulnerable or declining and likely to become endangered or threatened without cooperative management or removal of threats.


Grass Lake Wetlands

Wetland functions include water quality improvement, floodwater storage, fish and wildlife habitat, aesthetics, and biological productivity. An acre of wetland can store 1 to 1.5 million gallons of floodwater! Grass Lake Nature Park, owned by the city of Olympia, contains the headwaters of the main branch of Green Cove Creek and one of the most environmentally intact wetland systems in northern Thurston County. Sightings of over 100 bird species and 200 plant species have been reported.


The watershed needs our protection

External pressures – including development, climate change and pollution — will keep stressing this watershed. To preserve and restore the Green Cove Watershed, it needs continued attention and protection. OlyEcosystems is already at work in the watershed, helping to restore the headwaters of Green Cove Creek, along which we own 8.6 acres. We are trialing a systematic, manual approach for controlling Japanese Knotweed, which protects water quality in the creek.


OlyEcosystems is also turning its attention to the larger issue of the clear-cutting of over 20 acres near the Cooper Crest Open Space, which caused significant adverse environmental damage. OlyEcosystems has purchased this land and, in partnership with the community, began restoration in August, 2022.