Jackson Creek has an interesting history and has long been impacted by a series of human caused disturbances that have resulted in its habitat being compromised. In 1950, the creek was diverted into an excavated channel and directed into Netarts Bay. According to an article in the April 9, 1950 issue of the Oregonian, this action was undertaken by Tillamook County with the hopes of improving the salmon fishery. It was also hoped by some that the increased fresh water into Netarts Bay would help clear out sedimentation and improve commercial oyster production.
Jackson Creek was diverted into an excavated channel in 1950, shown here in this 2011 photo. The high sides of the channel keep the stream from interacting with a floodplain, reducing the quality of the fish habitat.
These intentions were well meaning, but ended up having negative impacts on aquatic habitat. It turns out that Netarts Bay is naturally a very saline environment, with only 14 small perennial streams providing a source of fresh water to the bay. In fact, the bay flushes itself with only 1.6 tidal cycles which is pretty rapid for a bay of its size. The fresh water contribution from diverting Jackson into the bay was minimal. Also, the creek likely contributes more to sedimentation, particularly in the south side of the bay where it regularly delivers material from the steep slopes of the Tillamook Highlands.
Diverting the creek into the bay also effectively cut off the ocean tributary from fish use. But this didn’t last long. A few years after the creek was diverted, it broke through the construction dam and some flows returned to the original channel. The flow of the creek has then been split between both channels- the historic ocean tributary and the newly constructed diversion channel- for the past 60 years. This had dramatic effects on the aquatic habitat. While fish have been using both channels, neither channel has had enough water in it to effectively support high quality fish habitat. Additionally, the diversion channel frequently went dry in the summer months and would strand juvenile salmon in small pools that eventually went completely dry. The diversion channel was also very unstable. It transported large amounts of coarse gravel downstream, and then would jump its banks and flow into portions of the campground. It wasn’t uncommon during these events to see juvenile salmon stranded in puddles in the campground!
Clearly, something had to be done. This summer, the Oregon Parks and Recreation Department teamed up with partners the U.S. Fish and Wildlife Service, Tillamook Estuaries Partnership, the Oregon Department of Fish and Wildlife, and the Oregon Watershed Enhancement Board to implement a large stream restoration project on Jackson Creek. As part of the project, the diversion channel was plugged and historic flows returned to the original Jackson Creek channel. A road ford, which had park vehicles driving across the creek to access the water treatment plant, was removed and a timber bridge will be installed to provide safe fish passage for all life cycles of salmon. And finally, the water intake that provides water from Jackson Creek to the park for use was effectively screened to prevent fish from becoming trapped in the park’s water system.
With all these improvements, it is hoped that adult fish will have an easier time navigating the ocean tributary as they come in from the ocean to spawn. Natural resources staff also hope that the original Jackson Creek ocean tributary will become more connected to its floodplain with the increased flow, providing a better place for young coho to rear. All in all, the creek has been returned to its natural condition and will provide a better experience for all park visitors- both human and fish!
For information on Waterways Consulting's involvement, please visit our Jackson Creek Restoration Plan project page... Click here
Link to Original Article: http://oprdstewardship.wordpress.com/2013/09/24/coming-soon-at-cape-lookout-state-park-better-habitat-for-fish/