Johnson Creek Streamwalk Report
July 17, 1999
- Members: Cathy Kenney, Jack Caldicott, Gina Hietpas, Beth Oakes
Before beginning our Streamwalk, and because we had the use of a 4-wheel drive Jeep, we decided to climb up Johnson Creek Road a few miles. Johnson Creek road heads toward Burnt Mountain off Happy Valley Road. After taking a left fork of the road, still climbing, we crossed Johnson Creek as it flowed under the road through a culvert (photos 1 through 3). Just up the road from the creek was an old washout from at least two years ago (photos 4 and 5). Backtracking and taking the right fork, we followed the lower border of an overgrown clear-cut to a turn-around area. There we saw extensive hillside erosion from this area toward the creek (photo 6). The water ran off a steep grade on the right side of the road, then crossed the road and down into the creek canyon. There was also a spring or the beginnings of Johnson creek on this side (photo 7). Johnson Creek Road showed signs of wear and tear - old washouts, and downed trees. Old culverts had been replaced fairly recently and there was a lot of new rock showing at the sides of the road (new grading).
After coming off the mountain, we went down into the canyon at reach 2. The plan was to go upstream in the creek as far s possible or until the creek appeared homogenous. We then splashed up Johnson Creek past the railroad trestle, under 101 through a concrete culvert, and a short way upstream from there. This area is probably about one-half to three-quarters of a mile downstream from the now defunct Reach 3. We observed gentle meandering here with some pool formation. What looked like bedrock up from the right wetted edge (looking downstream) was instead compacted clay in layers. There was little large woody debris here. Approaching the culvert from upstream, we noticed manmade embankment on both sides to retard washout. There was some garbage here. The culvert floor had metal "ridges" spaced perpendicularly to the creek's flow. Between the culvert and the railroad trestle, there were logs spanning the creek, a kind of stepping down, with notches carved in the logs close to the center. This may have been a way of fish passage. The low areas close to the trestle near the left bank contained large pieces of "garbage" - old bedsprings, tires, and rusty car parts as examples. At the base of the trestle was an artificial embankment in the way of cabled logs, broken up from a combination of movement and age. Downstream from the trestle is Reach 2.
We wanted to explore as much as possible of the creek between the reaches. We started at a footbridge close to the RV park across the road from John Wayne Marina. Johnson Creek retains its natural meandering upstream from the bridge. The canyon is, of course, not as deep here as at Reach 2. There is more light, but the banks are steep and in many cases undercut, most trees that have fallen are lodged bank to bank, and would be in the water only at flood stage. We trudged upstream until logs fallen from the banks cut off the passage. Actually, we got tired of climbing over them. The creek is very shallow at this time of year at most of the meanders - not more than three inches deep, and virtually no pool formation. I think we saw one pool. Heading back downstream, we noticed several outfall pipes sticking out from the right bank. At the footbridge, we noticed pipes attached to the underside of the bridge, with several disappearing into the ground on both sides. Johnson Creek from here on out to the estuary has been "man-handled" a great deal: it's been straightened, its banks have been rip-rapped, and there's virtually no natural creekside vegetation.