Watershed Assessment 2004
The Pescadero-Butano Watershed Assessment was undertaken to assess current habitat conditions
for Coho salmon and Steelhead trout in the watershed, and to identify factors limiting the quality
and extent of salmonid habitat. The overall goal of the project is to develop a scientific basis for
future management plans and actions related to restoration of the watershed and the salmonid
fishery. The specific objectives of the project are as follows:
1. Characterize the watershed and identify the areas of remaining high quality salmonid
habitat, that should receive high priority for conservation and restoration treatments;
2. Identify the factors and anthropogenic processes limiting the quality of salmonid habitat in
the watershed, and water quality generally.
3. Identify the most cost-effective treatments for improving salmonid habitat, and the areas
where these should be employed.
Historically, both Pescadero Creek and Butano Creek, as well as several tributary streams,
supported runs of Steelhead trout and Coho salmon. Steelhead are still present, but there have
been only sparse reports of Coho salmon in the watershed in recent years. Both streams are listed
under the federal Clean Water Act as impaired water bodies for sediment. It should be noted that
this assessment is not intended to substitute for, nor to form the basis for the development of
Total Maximum Daily Loads (TMDL) for the basin, though the study may be useful to others
undertaking their development.
The Pescadero-Butano watershed has been the subject of several past studies, as well as actions
and efforts by local residents to investigate and solve problems associated with the streams,
including flooding, landsliding, impaired water quality, and the declining fish population. The
Pescadero-Butano Watershed Assessment builds on past studies, and includes several discrete
new studies. These include a land use history (Chapter 3); a hydrologic analysis of the watershed,
focusing on the USGS stream gauging record (Chapter 4) and a study of the changes in stream
bed elevation at several County road bridges (Chapter 5); a geomorphic study of the watershed,
including an analysis of sediment sources and erosion rates since 1937 (Chapter 6) and current
geomorphology of stream channels (Chapter 7); and an assessment of current ecological
conditions, focusing on the quality of salmonid spawning and rearing habitat, and specific
impairments to salmonid habitat (Chapter 8). All of these studies are synthesized and conclusions
are presented in Chapter 2……….

