The Board of Supervisors this week certified a final assessment of the cumulative impacts of future development on the threatened and endangered salmonid species in the San Geronimo Valley watershed. The county has been working on the document—a supplemental environmental impact report to the 2007 countywide plan—since 2014, when the state’s first appellate court directed the county to do so in response to a lawsuit brought by the Salmon Protection and Watershed Network. Now that…