development by merging them with the large-scale turbulence of weather-related events as suggested in CPA’s proposed alternative methodology introduces very large uncertainties or errors that are unrelated to proposed Project Site development, and would tend to obscure the impacts of proposed Baylands development on the CPSRA wind resource.
The wind analysis for the Draft EIR qualitatively evaluates two variables—relative wind speed and turbulence intensity—that directly characterize changes in wind conditions occurring in the atmospheric boundary layer due to proposed Baylands development. Whereas large-scale turbulence can adversely affect windsurfing, wind speed is the most common primary indicator used by windsurfers of all skill levels to judge whether or not to go windsurfing on any given day. The Draft EIR thus focuses on the changes in wind speed as the most important and direct indicator of the potential adverse effect of the Project.
Furthermore, the relative wind speed measurement was used to support a qualitative evaluation in the Draft EIR of the effects of the Project on the measurement test grid (see Draft EIR page 4.M-11), but was not used to prepare a quantitative analysis as suggested in Comment Letter CPA 2. The magnitude, location, and extent of the decreases in wind speed were considered in the Draft EIR analysis. Pages 4.M-24 to 4.M-25 of the Draft EIR state a conservative range in wind speed decreases, from 5 percent to 10 percent, due to the proposed Baylands development. However, at least half of the test points over the grid show a reduction of 5 percent or less for all scenarios and wind directions, including locations near the existing CPSRA launch site. No “substantial degradation” of the CPSRA windsurfing area was determined from the qualitative evaluation of the wind analysis because proposed Baylands development would result in relatively small wind speed reductions and relatively small turbulence increases over the test grid, including locations near the existing CPSRA launch site.
Measurements of relative wind speed and turbulence intensity were calculated in the wind study based on wind tunnel testing. It is well documented in the scientific literature (see Master Response 31) that an atmospheric boundary layer wind tunnel can correctly simulate wind velocity, wind turbulence, and the power spectrum of the wind.15
The relative wind speed measurements (R-values) analyzed in the Draft EIR are independent of specific instances in time (refer to the description of the R-value on Draft EIR page 4.M-12). R-values were used to determine what the reduction of all wind speeds would be over the measurement grid at CPSRA as a result of the Project. Furthermore, R-values may be converted to absolute values, as explained under “Evaluation of CPA’s Alternative Impact Analysis” below.