Newaukum Creek flows from the forested foothills of the Cascade Mountains, through the farmland of south King County, and empties into the Green River before draining into the Puget Sound. The stream provides critical habitat for salmon to lay and fertilize eggs, and for juvenile salmon to grow to a size that will enable them to eventually journey to the open ocean. For salmon to have the best chance of getting strong enough to survive for up to four years, creeks like Newaukum need to be cool (to retain adequate oxygen levels), have plenty of gravel (for spawning) and wood (to provide shelter), and provide places for food sources (insects) to thrive.
A History of Warming Waters
The land surrounding Newaukum Creek are wetland soils and as a result are very rich and fertile. Because of this, in the early to mid-1900’s much of Newaukum Creek was dredged by farmers and laid with pipes so the water from the creek and surrounding wetlands could be used for irrigation; however, wetlands are not suitable lands for farming and many of the crops were ruined from flooding. Now these fields are overrun with invasive weeds like reed canary grass. Portions of Newaukum Creek have been straightened for irrigation and left with no native trees on the streambanks. The lack of shade along the creek has resulted in waters warmed to the point of being a lethal temperature for salmon. These temperatures affect not only salmon, but orca that feed on them in Puget Sound. If salmon can’t make it to Puget Sound, orca will go hungry.
Restoring Salmon Habitat
The King County Water and Land Resources Division and the King County Parks Division have been working together to protect and restore land along Newaukum Creek and its largest tributary, Big Spring Creek. Restoration activities focus on improving stream buffers to improve habitat and water quality for salmon, primarily through planting native trees and shrubs. King County started acquiring land surrounding Newaukum Creek in 2001 and has now conserved over 400 acres. Most of these lands are wet and regularly flood. Over 700,000 native trees have been planted in these natural areas over the last 20 years, including cottonwood, willow, and dogwoods. When these trees are planted, they are pounded into the ground as thick stakes, but within just a few years they grow into tall and dense trees. Once they are tall, they create enough shade to kill the invasive reed canary grass as well as moderate water temperature in the creek to levels cool enough for salmon to survive.
What’s Next for Salmon Habitat Restoration?
King County will continue to acquire and restore land along Newaukum Creek, but unfortunately this creek isn’t the only one in the county that has temperatures too warm for salmon. Climate change has created an urgent need to take action, and we are doing similar work on many other streams throughout the county. King County developed the Clean Water and Healthy Habitat initiative that aims to invest funds to help mitigate climate change and protect and restore water quality and habitat. In addition, trees planted along the creek will contribute to the County’s Three Million Trees goal to plant, protect and prepare forests for climate change. This restoration work also supports a variety of goals described in King County’s Strategic Climate Action Plan and 30-Year Forest Plan.
If you are interested in volunteering with King County Parks you can see our upcoming events on our Volunteer Portal.
If you are interested in hearing more about King County Parks’ environmental initiatives, please contact Sarah Brandt at sbrandt@kingcounty.gov.