Roads can cause many watershed problems. Forgotten roads can keep causing problems. As land uses and resource utilization techniques evolve, road needs change. When the roads associated with former activities are no longer needed, they have often been essentially abandoned, and closed with a gate or "tank trap". However, these roads continue to disrupt natural runoff patterns and can cause erosion as unmaintained drainage structures fail. They can cause revegetation problems for years. Sometimes they are the main reason that an area cannot be considered wilderness. More and more, public land management agencies are opting to completely remove their unneeded roads.

A common road closure treatment has been to build waterbars and, in some cases, remove the drainage structures. This helps prevent erosion, however, is often inadequate to meet the dual goals typical of most restoration projects: erosion control and revegetation. At Redwood National Park, a road rehabilitation program was initiated in 1978, with the goals of minimizing man- induced erosion and encouraging the return of a natural pattern of vegetation. Ultimately, the efforts were to result in the restoration of natural ecosystems to a condition similar to what would have existed without disturbance by man. Over the years, we have learned both what is possible, and what is cost-effective in watershed restoration work. We have not published much about our work recently...however, as more public land management agencies decide to obliterate their roads, this knowledge needs to be shared...we are hoping to have a publication out next year. In the meantime, we are offering field seminars on watershed restoration techniques, which cover the whole process from watershed inventories to contract preparation. This article summarizes our current treatment philosophies.

Our ability to effectively meet the overall goals of the program in the early years were somewhat limited by the minimal use of small heavy equipment, and not knowing what was possible in terms of road removal and restoration. Many areas treated in the early years are continuing to function essentially as intended, however, as time progresses, problems are becoming apparent with some of the treatments. Ditches and waterbars have locally filled with sediment, debris and/or vegetation, and are no longer functioning as intended; some partially excavated stream crossings eroded significantly, in excavation adjustments, potentially destabilizing the channel for some distance above and below the excavated area.

Stream excavations are generally done with a large excavator and bulldozer; the bulldozer can often remove the bulk of the fill unassisted, with the excavator finishing the channel. It is recommended that stream excavations be guided by someone experienced in interpreting soils and geomorphic indicators, as contract specifications often need adjustments in grade and depth in order to locate and follow the original channel course.

Retrieving sidecast fill and outsloping road benches restores the natural hillslope runoff patterns and minimizes the potential for future fill failures and debris slides. Pulling back sidecast fill and organic debris perched on steep slopes can directly reduce the amount of material that may eventually fail and enter a stream system. It is a permanent, maintenance-free erosion control treatment that keeps runoff dispersed. In comparison, ditches and waterbars concentrate and divert runoff, and eventually require maintenance or clearing.

One of the biggest factor controlling revegetation success, and ultimately the recovery of the entire native biological ecosystem, is the degree to which the soil conditions are physically restored along a road corridor. Outsloping, if done completely, can significantly aid this process. In outsloping, the concentrations of gravel and rock are dispersed, the depth of soil above bedrock is restored, and much of the original topsoil is retrieved. Topsoil is the first material to be sidecast during road construction, and is generally uncovered near the end of the outsloping process and spread on the finished surfaces. Thus, in order to retrieve the topsoil, the excavation of sidecast fill must be fairly complete. On extremely steep slopes, there may not be much topsoil to be recovered, however, recovery of even the subsoil provides a significant benefit in revegetating bare cut areas.

Visiting older restoration projects in Redwood National Park shows that outsloping dramatically speeds the re-establishment of native vegetation along road corridors. Many of the roads which received minimal treatments 8-10 years ago, such as ripping and waterbarring, have only sparse, small vegetation; nearby areas that were outsloped, and received the same revegetation treatments, are covered with dense, lush vegetation and the trees are significantly larger.

Outsloping is usually done by a combination of a large excavator and bulldozer. The steepness of the terrain generally dictates which piece of equipment is needed for most of the work. Typically, the excavator retrieves the more distant sidecast road fill, placing it against the road's cutbank, and the bulldozer shapes and smoothes the fill, as needed, to match the natural relief. Recent refinements in equipment application and resulting decreased treatment costs have allowed outsloping and topsoil retrieval to be widely applied in watershed restoration work.

Where desirable, a trail can be constructed along the outsloped road as the equipment finishes the work. This can provide foot or all-terrain vehicle access to restored areas for monitoring, planting or other land management activities. In exposed areas, the restored topsoil is protected with straw mulch when the work is completed. Trees (or other native vegetation) are planted during the first winter following the physical restoration work.

Road removal by excavation of stream crossings and outsloping road benches is the essential component of complete watershed or landscape restoration. It restores the natural runoff patterns and soil depth in the roaded area, which sets the stage for restoration of the native biologic ecosystem. A final benefit of road removal is the restoration of the aesthetic value of the natural landscape that can be achieved by the complete removal of unneeded roads. This is particularly important in parks, wilderness and recreation areas. It may, in and of itself, have valuable public relations benefits for agencies whose past land management practices are under public scrutiny. Road removal protects natural resources and enhances the quality of our dwindling natural wildland areas. In doing this work completely, you are leaving behind a legacy of caring enough to restore the earth for our future generations.

For further information about wildland restoration work or field seminars, you can contact Terry Spreiter at Redwood National Park in Orick, at 707-488-2911.