Revisiting Finney Creek…After the 2003 Floods
By Alison Studley, with assistance from the US Forest Service

Since 1999, the Skagit Fisheries Enhancement Group has partnered with the Mount Baker-Snoqualmie National Forest and the Crown Pacific Timber Company to restore instream habitat for threatened salmon runs on Finney Creek.

Finney Creek was historically the most important salmon stream in the lower portion of the Wild and Scenic Corridor of the Skagit River. Finney Creek provides access to over 11 miles of habitat for Chinook, coho, chum, and pink salmon, as well as steelhead and cutthroat trout. Resident trout also live in the upper watershed above a natural barrier for fish, a narrow rock gorge. Currently, Finney Creek suffers from abnormally high water temperatures during the summer months, which can kill juvenile salmon. High temperatures are primarily caused by a wide and shallow channel and increased exposure to the sun. In this case the channel condition is the result of large sediment loads triggered by logging of the hillsides from the 1970's to the present. These projects, along with other Finney Watershed restoration efforts, are designed to decrease sediment inputs and restore channel complexity for salmon.

Roger Nichols of the US Forest Service inspects one of the logjams
after the October 2003 floods.

To date, SFEG's projects have placed over 1,000 logs into 103 log jams in two reaches of Finney Creek covering 3 miles of instream habitat. Roughly 10 logs are cabled together to create each jam. The log jams are not anchored to the bank or the stream channel, allowing them to freely move as natural accumulations of logs would. The jams positioned in the upper reach of Finney Creek weighed an average of 25,000 to 29,000 lbs each and in the lower reach averaged 40,000 to 48,000 lbs. The purpose of the log jams is to increase channel roughness and complexity. The jams affect the local scour and deposition of the channel, sort gravel, increase sediment storage, accelerate natural pool development and stabilize the channel, creating a narrower and deeper stream channel. This technique of using logs to control sediment and change the shape of the channel will ultimately result in decreasing water temperature in the creek.

A great deal of monitoring has gone into this restoration effort. Baseline conditions were collected for water temperature, channel shape, riparian cover and macroinvertebrate diversity. Photo points were also established for each log jam location. Monitoring occurs at the sites each summer during low flow months, as high water flow and snow can prevent access to the creek during the rest of the year.

The project partners all looked forward to revisiting Finney Creek this summer after last fall's major flood events to see how the channel had changed. The 2003 flood events were the largest high water event to take place since the projects began, so we were all curious to see what types of channel changing processes had taken place. Below is a summary of what was observed.

The 82 log jams placed in the upper reach in 1999 and 2000 performed the functions they were intended to perform (storing sediment and helping to narrow the channel). These log jams had the benefit of modifying the channel over a longer time period than the lower reach and because they are farther upstream they endured less flow in the creek during the October 2003 flood series.

A group of log jams combined with flood-recruited woody debris in
a Finney Creek side channel.

Results were interesting in the lower reach, with over half of the log jams changing position dramatically. The lower 21 log jams were all installed last summer and did not have the benefit of smaller winter storms and incremental channel modification over time. Since these log jams are farther downstream than the others, there are more tributaries entering and thus more water in the channel, which created higher flows and likely impacted their stability during the flood events.

Monitoring of the lower reach indicated that 10 of the 21 log jams were still in the locations they were originally placed last summer, while the other 11 jams had been moved downstream by channel-wide debris jams forming and breaking. This natural process mobilized the placed jams as large wood units and repositioned them downstream within the next mile of channel and in one case several miles downstream. After careful observation, it was noted that the log jams tended to remain intact and travel as a unit. Multiple log jams tended to accumulate in one place in the channel, forming a massive jam of 30-50 logs (or 2 to 5 log jams). It was apparent from the sediment on the stream banks that during the flood huge accumulations of woody debris must have completely blocked the creek's flow for a time, allowing sediment to build up behind this massive debris jam. When the creek finally broke through this debris jam, a narrow channel was formed on one side of the channel leaving behind the new large log jam. "The channel changes were amazing. The channel narrowed dramatically and scour pools were present. The pools still lacked cover but when you walk down four to six feet of sand and gravel to get to the channel it's impressive," says Roger Nichols, USFS Project Manager.

While the fact that more than half of the log jams have changed locations since last year, may seem like a disaster, it could also be called "adaptive management". The log jams were installed with the ability to move with the water as needed and allow for natural processes to occur. Where the log jams ended up in the channel they have created even larger debris jams which will likely be more effective at changing the channel shape than the original smaller jams. These restoration projects began in the upper reaches of Finney Creek with the idea of continuing efforts downstream as the effects were monitored. Last year's floods just started moving the restoration project downstream sooner than we anticipated. Therefore, while the log jams are not in the locations they were originally placed, project partners agree that the new jams (where the floods have rearranged them in the channel) are just as effective, if not more, at meeting the restoration goals.

Cross sections of the channel measured throughout the project reaches have shown channel stability and narrowing in the upper reach. This stability has facilitated revegetation of stable bars where sediment is stored. Cross sections of the lower reach are not yet conclusive with only one year of data. While the ultimate goal of the project is to decrease water temperature in the creek, upper reach data indicates that temperature trends are cooler. SFEG plans to continue to work with the US Forest Service and other timber landowners on restoration projects farther downstream until the restoration goal is attained. Good partners have been the key so far to this success but as we progress downstream, willing landowners will be the future to the health of Finney Creek.