In the News

USDA Forest Service Upgrades Some Roads, Decommissions Others
date posted: December 22 2005

Lake Tahoe Report #83
Sept. 7, 2004
By John Cobourn, Heather Segale,and Rex Norman, Public Affairs Officer, USDA Forest Service, Lake Tahoe Basin Management Unit


In mountainous watersheds such as the Lake Tahoe Basin, one of the greatest sources of sediment is eroding roads, including their cut and fill slopes. This is why so many projects of the Lake Tahoe Environmental Improvement Program (EIP) involve controlling erosion along roads.

The USDA Forest Service (USFS) maintains 190 miles of “system roads” in the Tahoe Basin. The Lake Tahoe Basin Management Unit (LTBMU) is actively involved in an ambitious and expensive program to upgrade some of its forest roads and to decommission others. Since 1998, the LTBMU has decommissioned 66 miles of roads, 16 of those in the last two years. In addition, the LTBMU has upgraded 13 miles of its road system in the past two years. Upgrades are performed on roads that are becoming erosion sources. They eliminate negative impacts and maintain the road for both public and administrative access.

When an existing logging road has eroding cut slopes or fill slopes, and when its surface delivers sediment to creeks that lead to Lake Tahoe, the LTBMU must decide whether the road is necessary or whether it can be decommissioned. If it is needed for public recreation access, resource management, habitat enhancement, or hazard fuels reduction projects, it can be upgraded to eliminate negative impacts. This process involves making changes to the road such as rerouting sections, adding erosion control, fortifying banks, or installing other best management practices (BMPs). These changes are then maintained at the proper standards set by the USFS.

If a road is in poor condition and is not necessary, it can be decommissioned. Nationally, decommissioning of poorly designed or unneeded roads is being used more in the management of many national forests. In fact, the total number of miles of Forest Service roads has been decreasing in recent years.

Decommissioning a road can be more time consuming and expensive than building the road in the first place. The purpose is not only to remove the road, but also to restore the entire corridor through which the road once passed. This takes great technical expertise, since the road surface must be tilled to eliminate soil compaction, and the cut and fill slopes must be regraded to restore the original slope. The new surface soils must be amended with organic matter, planted with native species, and mulched to retain moisture and prevent soil erosion while the new vegetation gets established. The old road must also be blocked off, and signs must be placed to convince former users not to use the route again.

The LTBMU maintains 41,000 acres of public land in the Basin as inventoried “roadless areas,” where there is no road construction and no road reconstruction. These areas are available for dispersed, nonmotorized recreation. Unfortunately, off-road drivers create new roads each year. Once someone drives off the road into the forest, it only takes a couple of people to follow the path before it turns into a road Such illegal roads can increase soil erosion and disturb natural habitat, since they are not designed to avoid negative impacts. It is important for all forest users to stay on established and maintained roads and trails, whether on bicycles or motor vehicles.