The District has developed the Napa County Stream Maintenance Manual (SMM) to improve the management of streams and drainage channels in the District’s county-wide jurisdiction through establishing consistent guidance for stream maintenance activities. The SMM provides the organizational framework to oversee routine stream maintenance activities, including vegetation management, erosion protection and bank stabilization, sediment removal and habitat enhancement. The District’s stream maintenance approach relies on recognizing fundamental hydrologic, geomorphic and biologic processes that affect a given stream reach and adaptively manages and maintains streams based on the underlying processes. These maintenance activities occur mainly in engineered channels and “collectors”, modified channels and also in natural streams throughout Napa County on an as-needed basis.Updated Napa County Stream Maintenance Manual
Napa County Stream Maintenance Program Initial Study/Negative Declaration
Before: Large downed tree crossingDry Creek and causing debris jam.
After: Large wood and rootwad preserved,bank replanted and willow mattressesinstalled along bank.
The District performs annual stream reconnaissance and assessments to identify potential maintenance needs in District-maintained channels and in tributaries prone to flooding. The District develops an annual work plan and coordinates with the appropriate regulatory agencies to implement stream maintenance projects as needed. At the end of each maintenance season the District produces an Annual Report which provides project summaries, project maps and locations, pre- and post-photo documentation and summaries of habitat enhancement efforts.
Stream Maintenance Program Annual Report
Stream Survey Postcard
Before: Large downed tree constricting flowalong the Napa River.
After: Tree limbs crossing channel removed andlarge wood preserved to enhanceinstream habitat.
The District sees stream maintenance as an integrated stream management approach that involves protecting and enhancing existing instream resources while providing for necessary flood conveyance capacity in the channel. The District has integrated habitat enhancement efforts into the Stream Maintenance Program to protect and enhance instream physical processes, water quality conditions, riparian vegetation and instream habitat. The District partners with local groups and other government entities to implement stream enhancement projects including invasive species management, native riparian planting projects, barrier and debris removal, large woody debris preservation and supports watershed and flood control studies. The District also offers a Stream Bank Stabilization Cost-Share Program to assist property owners with stream bank erosion issues. The District's long-term vision is to create a diverse, mature and structurally complex riparian corridor that provides shade to the active channel, foraging and nesting habitat for many small mammals and birds, forage for aquatic species, moderates water temperatures and shades out invasive species. The District sees itself not merely as a flood management bureau, but more broadly as a resource management agency with a duty to integrate environmental benefits (such as habitat protection and enhancement) into stream maintenance activities.Stream Bank Stabilization Cost-Share Program
Stream Maintenance Flyer