It was a scary feeling to be the driving force behind the small but powerful 450 CASE 4 End Loader. Upon my command it would lower its front blade ten feet from the edge of the severely eroding stream bank, and start to push the soil and sod towards the stream. Inside I tried not to panic, wondering, "Was the treatment we had proposed going to be successful. Were we worsening the problem? Had we correctly read the landscape? And did our treatment plan build on the on-going natural processes?"

Perhaps for those of you who have been involved in a watershed or in-stream improvement project these same thoughts and feelings have appeared, especially when that heavy yellow iron starts moving soil or streambed about.

On the Stanislaus National Forest we started a Watershed Improvement Needs Inventory in l989. We surveyed seven watersheds covering 56,000 acres. The surveys included fish habitat and fish productivity typing, range condition and trend analysis, hillslope survey, stream and riparian condition, and road system effects on drainage and sedimentation. From this integrated survey several potential project areas were established in the North Fork Mokelumne watershed.

(Editor's note - The Mokelumne watershed that is the subject of our Fall Field trip).

Inventory crews had identified a section of stream 2700 feet long that had severely eroding vertical streambanks. Walking the streambank with Hydrologist Emeritus, Earl Ruby, we noted that in certain areas the bank had slumped off sufficiently to effectively stabilize themselves. This natural slumping process seemed to work best on fine-textured soils, but in more recent alluvial areas there was a large depositional area of coarse sands and gravels. The coarser material did not slump but maintained a vertical bank that was constantly being undercut. After several passes up and down the streambank, Earl and I began to get a picture of what processes were operating. Our strategy became one that would accelerate the natural processes.

This same segment of stream also needed fish habitat improvement. The wide channel lacked shade, and there were few deep pools available. Fortunately, the area had also been identified as needing lodgepole pine removal to increase the meadow for grazing. Sixteen of the tallest lodgepole were used for in-stream for fish habitat.

Treatment Specifics:
The streambank stabilization and fish habitat involved three stages. The first stage was to key into the banks the lodgepole pine that would enhance fish habitat. Sixteen trees were keyed into the bank on both sides of the stream. This was done with the 450 CASE front bucket. The trees were roughly 30 ft in length and had all the branches left on them. It would be wise in the future to remove the bottom 8-10 feet of branches so that the tree could be more securely placed in the streambank and have a more secure fit. Anchors were used to prevent the trees from moving.

Second stage involved a stair-step approach to pushing the sod banks, which were being undercut, into the stream at an angle to stabilize the banks. The sod was often 3-4 ft. above the stream and die back was evident since the roots could not access the water. As the banks were moved by the equipment, the sod would come in contact with the water, and within a couple weeks they were turning green. The areas directly behind where the sod once was had to be filled in with soil, in effect grading the site down to the stream. The area was then planted with native grasses and mulched.

The third stage of the treatment involved outsloping the banks with the coarse sands and gravels.

The work was completed in four days with equipment and the entire area was mulched with 100 bales of straw. Emphasis in 1991 will be to establish woody vegetation to further stabilize the stream banks. An active beaver population may not favor the use of willows, so early field review will focus on riparian species which are prominent in areas both above and below the treated area.

Bloomfield Campground: Streambank Stabilization

The natural migration process of the stream in the Bloomfield Campground had resulted in severely undercutting the banks below this popular campground. Several trees were overhanging the banks, and recreational access was dangerous, and was increasing the erosional processes.

Treatment focused on designing a rip rap wall where the stream was undercutting the streambank. We attempted to work around the existing trees. This made for more work and increased safety hazard. Boulders were recruited from a ten acre area with a rubber-tired front-end loader. This piece of equipment was quick and with its high maneuverability it eliminated the need for a dump truck.

The project site was constructed to dewater the area. Several steps were taken to meet BMPs: Work was done during the lowest flows in September, a sediment catchment basin was built, and a berm was built to prevent sediments from entering the stream channel. Construction of the rip rap wall consisted of digging an eighteen-inch trench where the 1-2 cubic yard boulders were placed. Smaller rocks and stones were placed in between the larger boulders to fill the spaces and to achieve a stable wall that would not fail during high stream stages. The entire area was reshaped with a CASE 450 after placing the fines. Fish habitat was also lacking in this segment of stream, and large boulders were placed instream to create some scouring around the boulders for fish habitat. Treatments were designed to fit with the natural environment. Future work will focus on stabilizing the streambank with willow cuttings. Another stretch of eroding streambank will be treated this summer after careful evaluation of the successes of the current treatment.

A few words of warning: When planning an improvement project in a public area be sure to post and educate the public as to what you are doing and why. Also try to avoid the opening weekend of deer season for your work! Keep in mind that a lot of our publics like remote areas that aren't improved, and we need to explain what the project is for.

Improvement work is a lot of fun, but it is important to review how successful your treatment was after a couple seasons. The Stanislaus N.F. plans on continuing watershed improvement projects, since the opportunities to improve soil productivity, enhance visual resources, create viable fish habitat, and protect water quality are plentiful.

Carolyn can be reached at (209)-532-3671