Evaluating Stream and Watershed Conditions in Northern California. Prepared for the California Department of Forestry, Fire and Resource Assessment Program

A map based approach for watershed assessment was developed to estimated potential salmonid habitat within two watersheds in Northern California. Current stream condition was assessed using stream gradient and streamside vegetation. For the entire study area roughly 40 % of the 900 miles of stream lengths analyzed were classified as low gradient response reaches. Within the riparian zone of response stream reaches 23 % of the area contained mature forests exceeding 24 ” dbh, while less than 10 % of the area contained late seral stage vegetation exceeding 36 ” dbh. Overall, the riparian forests were shown to be dominated by younger seral stage trees. Several indices were developed to represent the contribution of of roads and timber harvesting to sediment delivery in streams. A classification of stream types combined with information on potential recruitment of LWD, hillslope stability, and road related sediment provides a basis for a watershed assessment. This baseline data was used to develop a prioritization model to identify the restoration potential for each sub-basin. This model uses spatially explicit information from a Geographic Information System (GIS) to identify basins that are in need of short term sediment risk reduction, longer term forest stand improvements and existing habitat protection