River Corridor Base Map Posted

Dear Town Clerks,

The Agency of Natural Resources has posted a Base Map of river corridors on line at the Flood Ready Atlas  tinyurl.com/floodreadyatlas.  Click here to find answers to frequently asked questions.

River Corridors

What they are:  A river corridor is delineated to provide for the least erosive form toward which a river will evolve during floods over time.  River corridor maps guide State actions to protect, restore, and maintain naturally stable meanders and riparian areas to minimize erosion hazards.  Land within and immediately abutting a river corridor may be at higher risk to fluvial erosion during floods. 

What they are not: River Corridor Maps do not indicate any required action on the part of municipalities.  They are developed to facilitate ANR’s responsibilities in Act 250 to protect public safety from fluvial erosion hazards and to regulate activities exempt from municipal regulation under the Flood Hazard Area and River Corridor Rules. The Legislature has directed the ANR to promote municipal river corridor protection, but towns are not required, nor does the state have the authority to require the use of these maps by local communities.  Landowners are not required to get flood insurance within Mapped River Corridors. 

Over time, this newly posted map will serve as a place to composite data from the hundreds of separate river corridor and fluvial erosion hazard mapping exercises that have been conducted by our local and regional partners since 2004. The Base Map is a computer modelling product that will eventually incorporate both existing and new field-based stream geomorphic data (e.g., it does not yet reflect all those places where bedrock confines the stream channel). The ANR Rivers Program welcomes the opportunity to work directly with municipal and regional planning commissions in this process to ensure that the Statewide River Corridor Layer becomes a meaningful flood resiliency planning tool.

Two documents are attached;

ANR Releasing River Corridor Base Map:  gives background information on why the state has generated a statewide map, provides links to other river corridor and flood hazard mitigation planning information, and list the local data that may yet be incorporated to build a robust Statewide River Corridor Layer.

Reviewing the River Corridor Base Map: explains the types of map refinements the ANR is hoping to make before posting the Statewide Map on the ANR Natural Resource Atlas early in the new year and how people may participate in that process.  

Please forward this email to those in town governance or serving on municipal commissions whom you think would be interested in this information and click for more information about the map review and refinement process, river corridors, river corridor planning, and other frequently asked questions.