Sediment Delivery Monitoring

A great deal of effort and money is expended maintaining, improving, and decommissioning roads within the watershed. The objectives for the road network relevant to the strategies for the Aquatic and Riparian Ecosystem are to improve and protect stream and riparian ecosystems. The program is designed to:

  1. Reduce the road network to what is needed for watershed management under conditions of no timber harvest for commercial purposes
  2. Minimize sediment delivery to streams from roads
  3. Improve drainage patterns that have been altered by roads
  4. Reestablish fish passage, where economically and technically feasible, between significant amounts of upstream and downstream aquatic habitats, where these connections are interrupted by roads
  5. Track changes in sediment delivery to the aquatic system as a result of all road work.

While relying heavily on our comprehensive road inventory and predictions about sediment delivery using output from the Washington Road Surface Erosion Model (WARSEM) to prioritize road work and track improvements, the accuracy of these predictions has not been assessed, resulting in a significant source of uncertainty as to the effectiveness of our roads program at achieving one of our most fundamental objectives.

Sediment Monitoring

A sediment monitoring station along one of the roads in the watershed.

From 2008 to 2011, road surface erosion and delivery data was collected. It was used to quantify the actual amount of sediment produced from roads in the watershed as well as the effectiveness of road improvements at reducing road-generated sediment delivery to streams.

View the Road Surface Erosion Monitoring Plan (pdf).

For more information on the WARSEM model, see the Washington Department of Natural Resources website.