Logging and Water Quality- 500% Increase in Sediment Loads
San Francisco, Marin County and Santa Cruz all prohibit logging in their municipal watersheds. This prohibition exists because these municipalities understand a simple fact - logging in a watershed is bad for water quality.
Logging the Los Gatos Creek watershed WILL cause degredation in water quality. Logging, including the 'selective logging' proposed by SJWC, causes more sediment to be deposited into streams. This is a result of run-off from the land itself as well as the building of logging roads in watershed areas. Proof of this fact is contained in the US Department of Agriculture study entitled "Hydrologic Consequences of Logging Second-growth Redwood Watersheds" written by Robert R. Ziemer, Jack Lewis, and Elizabeth T. Keppeler USDA Forest Service, Pacific Southwest Research Station. This study showed an increase in sediment of up to 500% in the South Fork of Casper Creek in Northern California for 5 years following a selective timber harvest.
Here are excerpts from the study. The complete report can be found <A href="http://www.humboldt.edu/~rrz7001/pubs/redwood.htm">here</a>.
"From 1971 through 1973, about 65% of the stand volume was selectively cut from the South Fork watershed. Suspended loads in the South Fork increased by almost 400% (130 m3km-2) following roadbuilding and from 100% (30 m3km-2) to 500% (460 m3km-2) during the five winters after logging commenced."
Anyone drawing drinking water from Los Gatos Creek needs to be aware of what logging will do to the quality of that water. Keep in mind 11 different streams in the logging area feed into Los Gatos Creek.