16 Jun

DEEP POOL CREATED ON LOWER EAST FORK BY SWANSON STREAM HABITAT PROJECT IN 2010 IS PRODUCING RESULTS IN 2017 FOR SALMON FRY REARING

A “Stacked Log Complex” stream bank and fish habitat treatment was installed in 2010 on the north bank of the EAST FORK LEWIS RIVER as a component of the overall WA Fish and Wildlife and Bonneville Power, Swanson Chum Channel upgrade located about 3 miles above La Center, WA. Recent monitoring shows it is producing the results it was designed for.

Stacked Log Complex
7-23-2016 Air Photo – Swanson Stacked Log Complex Location on Lower East Fork L. R.

Previously, in 2007, flooding caused the riverbank at this bend of the river to severely erode and a group of large ash trees were washed away leaving a shallow streambed and bare streambank.

Stacked Log Complex

The structure design used, included a unique anchoring system, is one that has been used in the past to treat a specific type of problem where the river channel characteristics fit this kind of treatment. The almost immediate results were that the severely eroded bank was revegetated, the eroded overflow channel revegetated, and erosion on and sedimentation from that bend of the river was greatly reduced.

The Dean Swanson family, with collaboration from Friends of the East Fork and the local Healing Waters Veterans Group, have monitored and maintained the treatment as well as part of the overall Chum Channel project and program. Each year, the WA F&W puts between 90,000 to 130,000 chum fry into this special Chum Channel.

Stacked Log Complex

In May of this year, with the assistance of a guide and boat provided by the Salmon Creek Fly-fishers-Healing Waters Veterans Group, we floated the lower East Fork and took water depth measurements (using a survey rod and electronics) at key places in the river, including the channel at the Stacked Log Complex. The pool depth in the lower third and off the end of the log complex ranged from 4ft. to 7ft. The river water flow at that time was relatively low at about 460 cfs. (USGS Heission Gage).

In 2016, Friends of the East Fork purchased a GoPro underwater video camera to use for monitoring the lower East Fork river channel, and specifically the existing fish habitat, as well as other previously installed fish habitat treatments in the lower East Fork.

On June 7, 2017 we used the GoPro camera to look into the water under the lower end of the Swanson Stacked Log Complex. The purpose was to see if it was providing fish habitat and if there were any salmon fry or juveniles using the Log Complex. Photos of the Stacked Log Complex and the under-water views of the fish recorded by the GoPro camera are shown below.

Stacked Log Complex

In the video below, you will see quite a few small fish (salmon fry) and some larger fish that appear to be some kind of non-salmon (sucker or other species of non-game fish).

 

Below are 2017 GoPro Camera Video Capture Clips of Salmon Fry Using Swanson Stacked Log Complex
Stacked Log Complex
Stacked Log Complex

We also found salmon fry and juvenile fish using the pools at the new Phase-1 Swanson Powerline Bend river bank and fish habitat treatment structures, which was done in the summer of last year (2016). The intent is to install Phase-2 this summer in order to complete the fish habitat restoration and erosion protection at this upper bend of the river which is just above the Stacked Log Complex.

Assembled by: Professional Field Team Members: Richard Dyrland, Friends of the East Fork-Hydrologist and Shiori Baba, Geologist/Geomorphologist