Habitat Improvement at Tualatin River NWR
Chicken Creek Restoration
Beginning July 2019, a small tributary stream to the Tualatin River, known as Chicken Creek, will be restored to its natural, curving flow at Tualatin River National Wildlife Refuge’s Atfalat’i Unit. The project aims to restore natural stream and wetland floodplain functions, where the realigned Creek will feed a portion of the Atfalat’i Units once heavily managed wetland impoundments. Anticipated beaver activity in the restored Creek channel will cause water to pond, and in concert with the native vegetation planted by the Refuge, will result in 280 acres of wetlands and 2 miles of stream habitat supporting a healthy, diverse array of plants, fish and wildlife.
Mid-July, 2019 through September 2019: The project will begin with a delivery of large woody debris that will be used for habitat improvement in the Creek channel and its associated floodplain. This will require the Refuge to close a portion of the Wetlands Seasonal Trail (pictured below). That section of the trail will eventually be removed to connect the new 280-acre wetland site. A new section of trail will open in mid-July, providing access to a previously closed area of the Refuge while overall adding 1/2 mile of trail. This will be a permanent change to the Refuge trail system. Additional activities will include excavating the new creek alignment, filling ditches and the placement of the woody debris.
Fall 2019 through Winter 2020: Large scale plantings are slated to occur. Stay tuned for likely volunteer opportunities during this time.
May 2020 through September 2020: Beginning in spring 2020, work will start with the removal of water control structures and the installation of two new bridge crossings near the wayside and photo blind. Finally, late in the summer, flow from the current Chicken Creek ditch will be diverted into the new excavated Creek channel that was created during phase 1 and the ditch filled in.
Why return the creek to a curving flow?
Over 100 years ago, when this land was converted to agricultural use by Europeans, the portion of Chicken Creek that once meandered through the present day Refuge before it met the Tualatin River, was altered to become a straight channel, and reduced in length from 2 miles to 1/2 mile. While this allowed farmers to effectively manage the land for crops and dairy cows, it greatly reduced habitat for fish and wildlife.
When the area became a National Wildlife Refuge in 1992 the process of rehabilitating the landscape began. The land that is now referred to as the Atfalat’i Unit was divided into multiple wetland impoundments that, to date, have been intensely managed by water control structures and intricate water delivery canals in an attempt to mimic naturally functioning wetland systems. While this work has represented a positive first step for wildlife and people alike, Chicken Creek has remained in its unnatural straightened channel, as it did over a century ago, to the detriment of native aquatic species, floodplain wetlands, and Tualatin River water quality.
The faster flows in a straight and shortened ½ mile channel have limited rearing and resting opportunities for native aquatic organisms like cutthroat trout and western brook lamprey, compared to the slower flows of the meandering 2 mile natural creek system that once existed. Further, some of the water control infrastructure present barriers to habitat further upstream of the Refuge. Faster flows in a straight channel have also caused significant erosion of the current channel, preventing the creek from spilling onto its floodplain, while carrying copious amounts of sediment directly into the Tualatin River, creating water quality concerns associated with increased turbidity. By restoring the Creek’s natural curves for over 2 miles across the floodplain, and eliminating water management infrastructure, Chicken Creek will once again serve as the lifeblood of its floodplain. All the while greatly reducing the need for human intervention to sustain the thriving system.
partners in conservation
A project of this size requires the help of many beyond our Refuge staff, including wildlife. Refuge biologists and experts from our community partners anticipate some help from nature’s #1 engineers, the North American beaver. The restored riparian vegetation and meandering waters of Chicken Creek will entice beavers - who can’t resist the sound of flowing water - to become even more active in the area than they already are. Dam building will cause water to pond throughout the 280-acre site. As a result, wetland and riparian vegetation will thrive and a diverse array of fish and wildlife will benefit from more foraging, nesting, and protection opportunities.
From research, to know-how, to financial support, we also have many human partners to thank for this project becoming reality:
Starting July 2019, the Wetlands Seasonal Trail will be re-routed. A straight section of East-West trail between the Refuge Wayside and the North-South crossing trail will be closed during the project and eventually removed. A new, permanent section of the Wetlands Seasonal Trail will open at the same time, providing new views of the Refuge and an additional 1/2 mile of trail.
There may be additional temporary closures on the Wetlands Seasonal Trail when large equipment needs to move through the area.
Check back to Refuge2020.info and the Tualatin River NWR website for specific closure dates and other project updates.