This watershed rehabilitation project improved habitat for coho and Chinook salmon and steelhead in the north coast region of California by reducing sedimentation into Mill Creek and the Eel River. All roads having high erosion hazard were eliminated from Standish-Hickey State Recreation Area property on the north side of the Mill Creek basin. Mill Creek is one of the tributary streams of the South Fork Eel River that contains steelhead populations and is within the historical range of coho salmon; therefore, rehabilitation of this watershed directly improves critical habitat for these listed threatened and endangered species. Rehabilitation will occur by a reduction in abnormally high sediment loads that impact anadromous fish through increased streambank erosion, higher stream temperatures, filling of pools, increased embeddedness, and direct impacts on fish due to turbidity.
The work was performed by heavy equipment (primarily bulldozer and excavator) under the direction of California State Parks (CSP) personnel trained in landform rehabilitation. The project involved the removal of 4.6 mi. of abandoned logging haul road. The road removal required 359 excavator hours and 317 dozer hours over an eight-week period. It involved excavation of 14,717 yd.3 of road fill and 1,250 yd.3 from 11 stream crossings. The average distance production rate was 676 ft./day for the road removal. The maximum production rate was 1,340 ft. during one 12-hour day.
The Standish-Hickey Mill Creek Rehabilitation Project was implemented to eliminate erosion associated with numerous abandoned logging roads within the lower Mill Creek watershed at Standish-Hickey State Recreation Area (see map). The project involved removing stream crossings and recontouring abandoned roads using heavy equipment. By removing the crossings and roads, natural flow patterns and topographic features that were altered by road construction prior to park ownership were reestablished. Several of the roads removed had served as an improvised trail that wound its way into the middle reaches of the watershed near the park’s western boundary. As a result of poor alignment of the trail and the unstable terrain, the trail was abandoned in favor of a sustainable route lower in the watershed. The project area includes all park property north of the “Standish tree” and west of the Eel River. Due to time constraints and the scope of the project, it was broken into two phases. The first phase focused on the area north of Mill Creek and was conducted during 2000. The second phase of work was completed south of Mill Creek in 2001.
CSP and the California Department of Fish and Game (CDFG) California Coastal Salmon Recovery Program jointly funded the Standish-Hickey Mill Creek Rehabilitation Project. In March 2000, North Coast Redwoods District (NCRD) submitted a grant application to CDFG requesting $80,000 in matching funds to help complete the project. The project was selected for CDFG funding due to the fact that sediment reduction is a primary factor affecting salmonid recovery in the South Fork Eel River. The Roads, Trails, and Resources (RTR) section under the supervision of Maintenance Chief Don Beers implemented the project.
Setting
The subsurface geology of the area (as exposed in road cuts and excavations) consisted of sheared and broken shale, sandstone, and pebbly conglomerate. Most of the excavations were into previously excavated material resembling colluvium. Where native material was encountered, the bedrock appeared highly sheared and mixed.
Erosion and Sediment Problems
The watershed of Mill Creek, a tributary to the South Fork Eel River, has experienced extensive upland and inner-gorge landsliding. Detailed mapping conducted during the spring of 2000 revealed extensive instability on slopes throughout the park. Some of the instability resulted from extensive logging and road-building activities in the Mill Creek watershed from the late 1940s until its acquisition and addition to Standish-Hickey State Recreation Area in the early 1960s. The most severe problem in the park involved stream diversions in five locations that all contributed flow into an active landslide measuring 200 ft. wide, 400 ft. long, and 50 ft. deep. The diverted flows were actively expanding this landslide. Another major problem was a large inner-gorge failure that extended along both streambanks for 400 ft. that had flow from insloped roads draining into the head scarp. A third major problem was an 8-ft.-deep x 10-ft.-wide gully that traversed a slope on an old road for more than 800 ft. before cutting straight down the slope into Mill Creek. Numerous additional smaller gullies, rills, and slope failures also existed within the project area that were directly or indirectly related to roads.
Fish Habitat
Historically Mill Creek had runs of steelhead in its upper and middle reaches and coho salmon in the lower reach. The reach through park property has good woody material recruitment from large trees that were not removed along the creek during logging. Approximately 20 large old-growth redwood trees still exist on the slopes adjacent to Mill Creek. The streambed in the upper half of the park is composed of small to medium-size gravel in a predominately riffle/run habitat type. The lower reach is composed of small boulders in a rapid/pool habitat type. Some bedrock outcrops exist, which have caused the development of low-gradient aggraded reaches above with some short, steeper sections below. Reducing sediment yield to Mill Creek would help rehabilitate a former coho salmon stream, improve conditions for steelhead currently within Mill Creek, and improve conditions for salmon migration throughout the Eel River downstream from Mill Creek. Personal communication with Scott Downie, senior fish habitat supervisor with CDFG, indicates that he has witnessed steelhead migrating up Mill Creek, and those populations continue to use the Mill Creek watershed. Communications with fish biologist Bret Harvey from the USDA Redwood Sciences Lab indicate that the Eel River and tributaries within the Standish-Hickey State Recreation Area have significant populations of steelhead. Harvey plans to continue research in this area and believes the strong populations in this area are related to the tributary systems protected by the park. Park staff investigations have found numerous small fish using pools in the upper portion of the park.
Road Characteristics
The main access road to the project site was on Page and Gates Road, a park service road that crosses the lower-most part of Mill Creek on a railroad flatcar bridge. Page and Gates Road is currently used as a trail and for access by adjacent landowners. This road contributes sediment to Mill Creek at the crossing from the inside ditch on both approaches. Page and Gates Road was not affected by this road removal project.
Roads in the NCRD are classified by size, vegetative cover, surrounding topography, and the level of maintenance prescribed during the life of the road. A comprehensive discussion on road classification can be found in Wildland Road Classification – California State Parks Technical Memorandum (revised November 1999). Roads in this project area were of very similar size and type, had not been maintained, and were overgrown with vegetation, which increased the effort required for brushing and clearing.
The steep, narrow inner gorge of Mill Creek adjacent to the Page and Gates crossing made temporary construction of a low-water crossing for equipment unfeasible. In addition, the existing flatcar bridge was not suitable for equipment to use; therefore, an alternative route was selected to access the north side of Mill Creek. The access route in the upper portion of the park required development of a long, circuitous route to some of the more severe erosion sites. The route limited the ability of a service vehicle to access the equipment. This route also resulted in additional brush clearing with no further increase in stabilized fill, and it forced the operators to hike more than 1 mi. each day, resulting in a loss of production.
The lower one-quarter of the Mill Creek watershed is within the park. This area is currently used for recreation–mostly hiking, swimming, and sightseeing. The only significant park development in the Mill Creek watershed is a trail route, known as the Mill Creek Loop, which was developed by connecting a network of logging roads. The trail follows a network of industrial logging roads that were used for timber extraction before park ownership. Humboldt-style stream crossings, involving logs placed in the channel instead of culverts, had been used along the route. The Humboldt crossings were causing severe erosion during winter storm events. Therefore, due to the high instability of the slopes, the hiking route through the Mill Creek portion of the park was removed with funds provided by the NCRD.
A trail reroute was constructed to mitigate the loss of the Mill Creek Loop. The new trail was constructed in a portion of the park with stable soils and a low potential for impacts to the resources. The new trail has a curvilinear alignment and is outsloped to provide good drainage. The NCRD South Trail Operation (under the supervision of Sam Allsop) constructed this trail.
Mendocino Redwood Company (MRC) owns the upper portion of Mill Creek (south of the park). Although the company is not currently conducting habitat planning or rehabilitation in Mill Creek watershed, it is in the process of developing watershed management plans for adjacent basins. This effort demonstrates MRC’s interest in protecting fish habitat resources. Personal communication with a representative of Trout Unlimited indicates that MRC will be conducting habitat rehabilitation and erosion control on its property as part of the state-mandated total maximum daily load process, with some funding by CDFG. MRC foresters have requested copies of the NCRD’s Field Techniques for Forest and Range Road Removal and copies of its construction reports from past road removal projects.
MRC allowed use of a road on its property for access to the north side of the Mill Creek watershed. In exchange for the right to use this road, RTR decommissioned a half mile of logging haul road on MRC land, as described in the Entry Agreement. Fill from stream crossings was moved down the road to a dry, more stable storage location.
Project Planning
Geomorphic Mapping
Geomorphic mapping of the project area took place during February 2000. Two sets of air photos taken in 1963 and 1981 were obtained from California Department of Forestry and were color photocopied to create map boards. Geomorphic information observed in the field was mapped onto the map boards using a standard set of mapping symbols. (Refer to the Geomorphic Assessment and Mapping — California State Parks, Watershed Rehabilitation Technical Memorandum Series for more information related to geomorphic mapping.)
The mapping resulted in identification of 8 mi. of roads with high erosion hazard and related problems such as gulling and landsliding. This project treated 600 ft. of class II roads, 5,560 ft. of class III roads, and 18,185 ft. of class IV roads. Fill-slope failures, swale diversions, and runoff concentrations on these abandoned logging roads were contributing sediment directly into Mill Creek.
GIS
The geographic information system (GIS) database included the scanned air photo serving as a base map. This image was not orthorectified; therefore, the GIS could not calculate area and distance units. However, road lengths and fill volumes were measured on-site and entered into the database for each road segment. Road segments were digitized onto the base map and connected to a spreadsheet in which information on the road was entered. Other features of the landscape were added as separate layers including landslides, streams, and gullies. A final map was prepared and used as the construction specification.
Prescriptions
Prior to the heavy-equipment work, Project Supervisor Don Beers, Engineering Geologist Brian Merrill, heavy-equipment operators Glyne Johnson and Brian Hall, and Environmental Resources Intern Ethan Casaday hiked the project distance and developed prescriptions. All roads with 1 yd.3/lin. ft. or more of fill material were selected for removal. Other roads were selected for removal if they had any significant erosion problems or potential for problems, regardless of their fill volume. The prescriptions were entered into the GIS database developed for the project.
Volume Survey
Volume surveys were conducted using standard methods described in the Redwood National Park Watershed Restoration Manual 1992. Road prism measurements were taken at obvious changes in the road profile and used to estimate volume per linear foot. Measurements included road bench fill length, fill-slope length, and fill-slope angle. This information was not used for contract payments or for sediment reduction measurements. The volume estimate for this project is used for analysis of production rates for equipment operator comparisons and in the preparation of future contracts.
The volume survey for this project was difficult to implement due to the very thick vegetation cover on fill slopes and surrounding hillsides. Estimating the length of the fill slope is difficult because it is often unclear where the fill meets the natural hillside. However, the majority of the roads in this area were of similar size and for the most part separated into 0.2 yd.3/lin. ft., 0.5 yd.3/lin. ft., and 1.0 yd.3/lin. ft.
Environmental Documents and Permits
Prior to preparation of environmental documents, the project area was surveyed for rare and endangered species. Humboldt State University staff botanists surveyed the entire area for rare plants. No federal- or state-listed rare plants were discovered in the project area.
The project site was also surveyed for the presence of potential amphibian habitat. No populations of federal- or state-listed threatened or endangered species were identified in the project area. Potential habitat was flagged and mapped by a local biological consultant. The consultant also provided amphibian habitat surveying training for state park staff. During this training, the consultant determined that road removal projects will have an overall benefit to amphibians by increasing potential habitat.
The NCRD was the lead agency for this project and prepared documents required by the California Environmental Quality Act (CEQA). After review of a project evaluation report by district staff, a draft negative declaration was prepared. At the time of project planning, the district senior ecologist position was vacant, which resulted in long delays in preparation of the negative declaration. Following public review of the negative declaration, as required by CEQA, the regional ecologist and the state park director signed a notice of determination that the project would not have a negative effect on the environment. During the review period, no comments were received from state agencies or the public.
Contract Implementation
The contract work for this project was implemented between August 21, 2000, and October 19, 2000.
Park Staff
RTR trail crewmembers were at the project site to assist with project implementation. The main function of the crew was to clear brush from the road alignment. They used hand tools to remove all trees and brush from the cut slope. The hand crew also removed trees marked with red paint from the fill slope, which the inspector had previously marked.
Operators and Equipment
The contractor for the implementation of the rehabilitation prescriptions was Paul Deneau Construction from Redding, CA. The contractor operated a 17,000-lb. John Deere 190E excavator. Deneau has operated excavators, bulldozers, loaders, and other heavy equipment for more than 30 years, gaining most of his experience on pipeline projects. Recently, Deneau has gained watershed rehabilitation experience working for the Trinity Resource Conservation District and the US Forest Service. He has also been involved in contract work for state parks on past projects. Tom Hale, equipment subcontractor, operated an 18,400-lb. Dresser bulldozer with a six-way blade. Hale also has experience in road rehabilitation projects from working for the Forest Service and has numerous years of equipment experience working in the timber industry.
Prior to construction, the inspector and operator spent two hours reviewing the Field Techniques for Forest and Range Road Removal, looking at photographs from past projects, and discussing techniques and specifications. During this meeting, the NCRD’s safety protocol and the construction contract were reviewed and discussed.
Equipment Move-In and Move-Out
The equipment move-in consisted of walking the two pieces of equipment from State Highway 1 adjacent to Leggett, CA, up the Page and Gates Road. The 2-mi. move-in was required due to the narrow switchbacks on the Page and Gates access road, which were difficult to navigate in a standard low-bed transport vehicle. This part of the walk-in required one hour for each piece of equipment.
For fuel supply, the contractor hauled diesel in a service truck to the job site. For three weeks of the project, however, the service truck was unable to drive to the equipment because of very steep road grade and loose soils. During this time fuel was hauled to the equipment using 5-gal. fuel cans transported on an all-terrain vehicle (ATV).
The ATV was an extremely useful tool, improving efficiency and safety during the project. At times the equipment worked more than a mile from the service vehicles. The ATV hauled diesel fuel, a chain saw, first aid and safety equipment, fire and mechanics tools, a radio, a cell phone, and food and water.
Site Preparation
Marking paint in a spray canister was used to help operators visualize crossing excavation locations. This helped reduce the possibility of misaligning a stream channel excavation or underexcavating the crossing width. The markings on the ground quickly disappeared when equipment work began and were intended for visualization before excavation.
Manual brush clearing accompanied the initial brush removal by heavy equipment. Park employees used chain saws and pole saws to remove small trees and brush that were overhanging the road. This organic material was placed in the road where the dozer then pushed it into piles.
Historical and Cultural Resources
The only cultural artifact found during the project was old logging cable and a part from a bulldozer. These items were left intact to the side of the road-recontouring site. Other evidence of historic use included one large stump that still had springboards in place from early logging.
Road Removal
Removal of road and skid trails includes retrieving material side-cast during road construction and excavation of stream-crossing fill. This fill is placed against the adjacent cutbank and shaped to blend with the surrounding topography, forming a “full recontour” where feasible. Where a complete match to the existing slope was not feasible at a site, a “partial recontour” was constructed. Partial recontouring was used where a road to be removed was adjacent to an area where numerous roads were not being treated (because they were outsloped and did not require treatment). Partial recontouring also occurred where excavated fill material was insufficient to allow matching the restored slope to the top of the existing cut bank.
In some cases, decommissioning involved preserving the road bench, but outsloping it to improve sheet flow, while removing all stream crossings.
Restored fill was compacted in lifts to reduce the potential for recontour slope failure. A full recontour to the natural slope was obtained along 70% of the road removal length and a partial recontour on the remaining 30%.
Organic Material
Organic material was separated from the fill and placed on the recontoured surface to protect against raindrop splash and sheet erosion. Logs and large pieces of organic material were placed on the slope surface and were tamped down to provide contact with the soil surface. In some places the organic material placed on the final surface had 100% coverage and was up to 3 ft. thick. The inspector used a chain saw to cut brush mulch into smaller pieces to allow better contact with the soil.
The prescriptions called for placing logs perpendicular to the slope direction. Due to the extra time involved with aligning material in this direction, however, the inspector made a decision to allow mulch to be randomly placed. It is anticipated that, because of the thick mulch layer, randomly placing material will not have a significant effect on sediment transport or delivery.
Stream-Crossing Removal
Stream crossings were excavated to recontour natural channel shapes, and attempts were made to locate natural channel features. The excavation of stream crossings involved locating buried stumps; boulders; logs; and black, organic-rich soil as indicators of the location of the natural stream channel. Stream crossings were excavated to original width, depth, and slope, exposing natural channel armor where possible. Sideslopes at crossings were generally configured to match original contours above and below the road. Additional logs were placed against the upper banks of stream crossings to prevent soil detachment from overland flow. Material excavated from streams and other watercourses was placed in stable cut locations along the roads.
Access-Road Winterization
The 2 mi. of access road from the Page and Gates Road to the north side of Mill Creek was winterized on the last day of the project. The winterization included removing fill from one stream crossing, removing fill from four topographic swales, installing eight rolling dips, and outsloping 200 ft. of road. The primary purpose of the winterization was to remove the stream-crossing fill from a road segment that will have a complete road recontour in the next phase. The removed crossings will allow the second phase to take place without the need for a Streambed Alteration Agreement.
Sediment Savings
State park geologists estimate that more than 113,000 yd.3 of sediment will be prevented from entering the adjacent streams as a result of this project. This large sediment savings is due to the fact that the road rehabilitation will reduce the likelihood of landslide enlargement. The removal of stream-crossing fill eliminates the potential for fills to fail directly into stream channels. The project also eliminates the diversion of flow into large gullies directly above Mill Creek. In contrast to landslides and stream-crossing failures, gullies formed from diverted stream flow are not self-limiting geomorphic features; that is, they are not likely to stop expanding once a stable configuration is established. Instead, the gullies continue to downcut and widen for a long period of time before a new equilibrium is established. With that in mind, the estimated quantity of avoided sediment yield is considered to be the minimum value.
Postconstruction Analysis
Organic Material
The removal of standing trees and the handling of woody material required more than 50% of the time expended upon the contract. The project site had a heavy brush cover, and 10% of the excavated fill material was composed of large woody material.
Collection and placement of organic material, known as “mulching,” should be analyzed in future projects to better understand how it affects production rate. It would be interesting to record the number of bucket loads of organic materials moved per day. If possible, the project inspector should record the number of bucket loads of organics versus soils moved per hour at various points during the project. A more detailed survey would be to use a stopwatch to record the exact amount of time each task represents during the day. Sufficient data collection on brush handling was not collected because the inspector spent most of the time working with the bulldozer operator, who was opening roads and making the initial excavations.
More research is needed on the cost and effectiveness of applying various types of mulch to disturbed areas. In addition to providing the desired protection against raindrop impact, any mulch used should not slow down natural revegetation or introduce any exotic species to the site. The cost associated with spreading mulch that is produced on-site should be compared to the costs of importing mulch such as redwood bark, straw, or hydromulch. The current approach of the NCRD is to apply masticated brush mulch from materials collected on-site using the excavator. Placing all brush in a windrow downslope from the road would reduce equipment time. For other areas, importing mulch and spreading it by hand might be more costly than the time saved by making an additional windrow.
Brush Removal
Removing small trees and brush during heavy-equipment work appears to produce the best results. A chain-saw operator and a swamper should work with the equipment as they move into a site. Complete brush removal is not necessary, but standing material should be removed as required so the excavator swing capability is not limited during recontouring. Felled trees should be bucked into 10- to 20-ft. lengths and piled up on the outside edge of the road. The shorter pieces of wood are much easier for the excavator to place on the final surface. The downside of this method, however, is that trees that are cut and bucked have sawed ends that look less natural than trees that are snapped off by the excavator.
For future projects, the number of trees left in the fill slope should be limited. Excavating around trees left in the fill slope might leave them vulnerable to wind-throw or uprooting. On this project, however, the small size of the equipment made it difficult to remove trees standing in the fill slope. The small-size excavator made it difficult to push over trees with a diameter at breast height
