Over the past couple days, SFEG staff and interns have been completing our annual Finney Creek cross section surveys. If you aren’t entirely sure what a cross section survey is, allow me to explain… but first, a little background on Finney!
Finney Creek, a major tributary of the Skagit River, was historically one of the most productive salmon streams in the Lower Skagit River area. In recent years, however, this has not been the case. The hills that rise above Finney Creek have been heavily logged, which increases erosion and the amount of sediment that runs off into the creek.
Over the years, this has resulted in a wider and shallower creek than we might have seen in the past. While it may feel great to dip our feet in a warm stream, it does not feel good to the salmon that call Finney Creek home! Any water temperature over 68 degrees Fahrenheit dramatically decreases a salmon’s chance of survival. Water in the 40-50 Fahrenheit range is more ideal.
In 2002, Skagit Fisheries Enhancement Group took on Lower Finney Creek, the area I visited yesterday, to try and add some complexity to the stream bed and create better habitat for salmon. We did this by adding what in restoration terms is called “LWD,” or Large Woody Debris. These engineered log jams replicate the kinds of log jams that used to be all over the Skagit watershed historically, and may appear nowadays during a flood or storm. They may be troublesome in places where we don’t want them, but these log jams are actually a big help for shallow, uniform streams that tend to get too hot. Log jams tend to collect excess sediment above the jam, and form deeper pockets and pools beneath them. In 7 years, we installed 107 log jams over 10 miles of creek!
Well, after an endeavor like that, we’re hoping that Finney Creek will become deeper and cooler. The best way to measure our success is by conducting cross section surveys, where we measure the underwater topography of the creek. So, in case you were wondering how to do it at home, here are some simple instructions!
How to Conduct a Cross Section Survey
1. Extend a measuring tape from one bank of the creek to the other.
This tape helps us record the same distance from year to year and keeps our measurements constant.
2. Set up your survey equipment!
A level keeps us honest with our measurements, especially when a tape bows over a wide creek bank. They also work great as binoculars for wildlife. Notice the butterfly bush in this picture – the banks of Lower Finney Creek are infested with butterfly bush! While it’s beautiful in a garden, it’s a real problem and invasive species up here in this riparian area.
3. Record the height of a measuring rod at regular intervals.
These distance points help us to connect the dots when we map out or graph the stream channel later.
4. Pack up and repeat again next year!
We’ve been collecting data from Lower Finney Creek ever since the last log jams were installed in 2010. While we may not know how the log jams have affected Finney Creek yet, we’re hoping to get those answers by collecting information about the creek annually.
When we take the height measurements we’ve recorded and map them, it ends up looking like this:
and every year, the stream bottom is different.
This year, Finney Creek’s flow was shallower than it has been in past years, but that’s a Skagit-wide phenomenon. It made it great for noticing tiny salmon fry and heaps of caddisfly larvae that inhabited the bottom of the creek bed. Masses of tadpoles also darted around in the crystal clear water.
We’re hoping that Finney Creek can retain its natural beauty and productivity and also become even better habitat again by changing its course and becoming deeper and more complex, with more riparian vegetation to give it shade.
To learn more about our work on Finney Creek, check out our project page on Habitat Work Schedule.
Have you ever visited Finney Creek, and how was it? Post your comments or questions below!