The Napa River flows though one of the most scenic landscapes in the Bay Area, and supports one of the largest remaining salmon runs, but it faces many challenges. In the mid 20th century the river corridor was squeezed from a broad ribbon to a narrow thread, as land managers cut off secondary channels and confined the river behind levees. At the same time urbanization and land drainage funneled more water into a narrower floodway. The result was channel incision – unable to spread its energy across a wide floodplain the river cut down into its bed, causing the banks to fail.
