Abstract
The Battle Creek watershed in northern California was historically important for its Chinook salmon populations, now at
remnant levels due to land and wat er uses. Privately owned portions of the watershed are managed primarily for timber
production, which has intensified since 1998, when clearcutting became widespread. Tur bidity has been monitored by
citizen volunteers at 13 locations in the watershed. Approximately 2000 grab samples were collected in the 5-year analysis
period as harves ting progressed, a severe wildfire burned 11,200 ha, and most of the burned area was salvage logged. The
data reveal strong associations of turbidity with the proportion of area harvested in watersheds draining to the measurement
sites. Turbidity increased significantly over the measurement period in 10 watersheds and decreas ed at one. Some of these
increases may be due to the influence of wildfire, logging roads and haul roads. However, turbidity continued trending
upwards in six burned watersheds that were logged after the fire, while decreasing or remaining the same in two that escaped
the fire and post-fire logging. Unusually high turbidity measurements (more than seven times the average value for a given
flow condition) were very rare (0.0% of measurements) before the fire but began to appear in the first year after the fire (5.0%
of measurements) and were most frequent (11.6% of measurements) in the first 9 months after salvage logging. Results
suggest that harvesting contributes to road erosion and that current management practices do not fully protect water quality.