County Expresses Serious Concerns About Logging Plan
The following are report excerpts written by a hydrologist and fisheries biologist representing Santa Clara County regarding concerns related to the SJWC logging plan. The full reports are now public record. These comments reflect serious concerns about the plan by the scientific reviewers.
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In the San Jose Water NTMP site, high rainfall, major deep and shallow landslides underlying residential areas bordering the proposed cutting zones, and the fact that redwood trees are notorious for 'profligate' water use raises immediate concerns about the potential effects of forest management on slide stability and public safety. My conclusions are that the proposed cutting schedule and volumes will most certainly contribute to slide instability including increased rate of motion of existing deep-seated slides that affect residential areas, streams, and highways within the NTMP areas of the southwest side of Los Gatos Creek and along Briggs Creek.
The primary basic premise of the authors of the NTMP is false. They say that timber removal from deep-seated slides is contemplated but that it will not destabilize slide masses....Timber removal will accelerate sliding near the slide head and near its base. The middle will follow.
Tim Best has recommended mitigations for the sites identified in NTMP Section 5…, but concludes that “It is very unlikely that the proposed harvest will have any measurable impact on deep-seated stabilityâ€. I believe that I follow his reasoning but disagree fundamentally.
….field traverses and calculation of changed water balance show that this basic premise is both false and very dangerous.
Today’s closed canopy forest is proposed to be opened in each cutting cycle, thus increasing growth of shrub and hardwood species that are now not common over the primary timber production areas. Such increased shrub growth increases fire danger …
The majority of the NTMP timber production zone is mapped as landslide…
The consequences of unmapped compound slides are that proposed timber harvest roads and cutting units probably cross onto active slide areas and displace surface water into obscured scarps, thus accelerating unrecognized slide masses that carry increasing sediment loads into the watercourses at the base of the slides. Sites that should at least be classed as special treatment areas with no tractor entry will not be recognized until it is too late to avoid the damage.
….the revised Figure 2A “Landslide Map†from Best indicates that he recognizes nested features that he classes as “large failures†below Chemeketa Park and below Call of the Wild.
The NTMP has not adequately evaluated natural rainfall intensity in the project area and thus underestimates winter condition site preparations such as culvert diameters, crossing design, and road standards for winter access.
The proposed NTMP is not soundly based in its assumptions about harvesting on deep-seated landslides that dominate the proposed harvest areas.
I estimate that 63 percent of that merchantable basal area would be equivalent to about 48 trees to be harvested per acre.
The NTMP has not adequately evaluated natural rainfall intensity in the project area and thus underestimates winter condition site preparations such as culvert diameters, crossing design, and road standards for winter access.
It is possible that the stream is just now beginning to recover from cutting in the late 1800’s that destabilized slide masses that were then exacerbated by the 1906 earthquake.
Thus, changes that may be imposed by the proposed NTMP must be added to past stress responses and may reasonably to expected to lengthen the period of natural recovery of the stream course in that watershed.
It would seem prudent to simply avoid any harvest or road activities in the slide zone, which also includes the riparian zone.
….it is certain that the proposed harvest schedule will seriously exacerbate slide stability.
Because the Santa Clara County residential areas between the Summit Area and Chemeketa Park, including both sides of Highway 17, are located on these deep seated slides that support the trees to be cut in the proposed NTMP, the potential liability for San Jose Water Company if they carry out the propose NTMP harvest plan becomes extraordinary.
Robert Curry, PhD, Hydrologist
The NTMP erroneously states that there are no non-listed species which will be significantly impacted by the operation. Coldwater species including landlocked steelhead/rainbow trout and riffle sculpin are potentially present in the project area. These non-listed species may be significantly impacted by the operation. Potential impacts are related to habitat degradation through increased sedimentation, increased water temperature, and barriers to migration at stream crossings of Class I and Class II watercourses. These potential impacts are not considered or evaluated.
Data presented in Section V of the NTMP indicates that existing temperatures approach the upper threshold of suitability for coldwater species and contradict statements elsewhere in the NTMP that temperature is not a limiting factor.
The NTMP provides no assurances as to the degree to which the avoidance and mitigation measures for soil stabilization and erosion control will actually be implemeneted.
Jeffrey Hagar, Fisheries Biologist