Eroded forest road due to poor planning
Best Management Practices After the Timber Harvest

Installing water bars

This web article explains how forest workers and landowners can use water bars to control erosion after a timber harvest.


Water bars are a combination of a mound and trench angling across the road to intercept and disperse water flowing down the road surface. Because they form a significant, almost impassible bump in a forest trail, they are placed where machinery will no longer travel. If the landowner wishes to continue using wheeled equipment on the road for recreation or obtaining firewood, broad-based dips can be substituted for waterbars.

The idea is to divert water off the road and into a more stable vegetated area.

Water bars are built at a 30 degree angle to the road course. The distance between water bars will vary from every 250 feet on gently sloping trails to every 40 feet on steep trails.


The height of the mound will also vary from 8 - 30 inches; lower on gentle slopes, higher on steeper slopes.

To complete the construction, the runoff area at the bottom edge of the water bar should be stabilized with coarse stone or seeded grass.

Drawing from Wisconsin's Forestry Best Management Practices for Water Quality (1995)
Photo from Jeff Martin WI DNR
Home | Index | Tools for Planning a Harvest | Cornell Cooperative Extension ForestryCornell Cooperative Extension helps forest owners

Please cite source: Cornell Cooperative Extension, 2004
Written by James Ochterski, CCE - Schuyler County