Forest roads are essential for getting timber to the mill, and for fighting wildfire. Yet some roads, especially older roads, are a source of sediment flowing into streams.
With significant amounts of research and innovation over the past couple decades, the way forest roads are built – and where they are built – has been overhauled.
Location is key
Today, forest roads are more often located away from streams and other water sources, so any runoff is drained onto the forest floor. Nowadays, roads are often located on ridgelines, for instance, and away from steep slopes.
Engineered to lessen impact
Excavation, surface preparation, drainage, gravel installation and grading are typically planned and overseen by a civil engineer to minimize the chance that muddy runoff will enter streams or other waterways.
Maintained for the long run
Forest roads, whether new or old, must be inspected and maintained to minimize the effects on nearby streams. New gravel, drainage systems, culverts or bridges may need to be added over time. If a road is no longer needed, it should be vacated, re-contoured and, ideally, replanted with native vegetation.
Account for fish and water
While engineers try to minimize the number of times a forest road crosses a stream, some crossings are inevitable. At crossings, rules require drainage to divert road runoff onto the forest floor, not into the stream. Rules also require that the crossing allow fish to pass up- and downstream.
Watch the weather
One of the recent changes to the forest practices rules puts additional requirements on roads that are used during very wet weather. Roads that are not up to the standard may not be used during heavy rain.
Anna Vesper of McGee Engineering discusses how to design and maintain forest roads to ensure the protection of water quality in Oregon's working forests.