Flooding and Maps
Flooding is the region and state’s most prominent hazard. Floods have destroyed homes, businesses, roads, railroads and bridges. Flooding has hit the region in the past, and it will again in the future. Flooding can happen any time of year – intense summer thunderstorms, tropical remnants in the fall, ice jams in winter and spring snowmelt. Be ready for floods! There is considerable evidence to support that floods are increasing in frequency and severity. It is important for towns and their residents to lessen flood damage by generally refraining from building or filling in floodplains and near stream channels; properly constructing and maintaining culverts, roads and ditches; and requiring private ponds to be constructed to avoid failure.
Flood Ready Vermont has lots of useful information for community leaders and planners including:
- Community Reports– summaries of risk data and community efforts
- Vermont Flood Ready Atlas – online map with popup reports
- Update Your Plans– municipal development planning and other community efforts
- Emergency Relief and Assistance Fund (ERAF)– qualify for more aid after a disaster
- ERAF Summary Report– community mitigation actions and ERAF rate
- Get Help– links to people, organizations, training and other resources
- POLICY information by TOWN updated (Use Firefox or IE)
Flood Maps and River Corridors
FEMA has mapped a variety of flood hazard areas, and Vermont has gone further and also is mapping areas along smaller streams and river corridors where erosion is a greater risk than the inundation shown on the FEMA maps.
- FEMA Map Service Center: Search with an address in the upper left.
- FEMA NFHL Viewer: Search with a map.
These sites can be slow but the TRORC online map below shows flood data for our region and includes both official and unofficial digital data.
Vermont has also completed its own flood hazard mapping through the identification of river corridors. A River Corridor includes the meander belt of a stream or river and a buffer of 50 feet. The River’s program has developed river corridors for streams draining at least 2 square miles. The rest of the mapped streams have a 50′ buffer from the top of the bank. The official map is available below through the TRORC online viewer or at https://tinyurl.com/floodreadyatlas. River corridors minimally encompass the meandering of a river in the least erosive form. They are drawn with the expectation that new and existing structures outside the corridor may be protected from lateral channel migration using bank stabilization practices without creating new or additional hazards. Within a river corridor, existing infrastructure and improved property may be at a heightened risk from erosion and be more likely to require river management to protect over time. River Corridor as defined in Vermont statute:
“River Corridor” means the land area adjacent to a river that is required to accommodate the dimensions, slope, planform, and buffer of the naturally stable channel and that is necessary for the natural maintenance or natural restoration of a dynamic equilibrium condition, as that term is defined in section 1422 of this title, and for minimization of fluvial erosion hazards, as delineated by the Agency of Natural Resources in accordance with river corridor protection procedures. 10 V.S.A. Chapter 32 § 752. Definitions
Flood Mapping Updates starting 2020-2021
Flood map updates are planned for our whole region in two groups. The White-Ompompanoosuc-Waits-Wells watersheds started in the summer of 2020 and the Black-Ottauquechee started in the summer of 2021. These updates will take several years (up to five) before we see the final products. But these updates will use the new LIDAR elevation data improve the mapping products and create much more approximate level mapping (base level engineering or BLE).
Black-Ottauquechee- These watersheds are being coordinated by CDMSmith and the contact is Alexandra Rodriguez, [email protected].
Flood Insurance and Regulations
Every town in the region participates in the National Flood Insurance Program (NFIP) by regulating development at least in the FEMA NFIP designated flood zones on Flood Insurance Rate Maps (DFIRM or FIRM). Anyone in the region can buy flood insurance, and those living near a river or stream should seriously consider this insurance, even if not required, since a significant amount of flood damage in Vermont has occurred outside of mapped flood zones. Homeowners’ policies never cover flood damage. To find out about your local flood regulations, contact your town zoning administrator or administrative officer through the links to the right. Every town has such a person.
The flood web-map viewer below shows official River Corridors for the state and FEMA NFIP DFIRM flood hazard data for Windsor and Rutland counties as well as unofficial FEMA data for Orange and Addison Counties. Please note that if you live in an Orange County town that borders Windsor County, the effective dates of the Windsor flood map panels will overlap into Orange County. It will look like you have 2007 data available but this is not the case. The map below also shows streams with watersheds draining between 0.5 and 2 sq miles with a 50′ buffer. To qualify for ERAF increased disaster funding, towns must protect mapped river corridors and streams with watersheds between 0.5 and 2 sq miles. The buffer is shown on the map but must be determined in the field from the top of the streambank back 50′.
Floodplain Management Resources
- Floodplain and Corridor Protections Model Bylaws
- Vermont Regional Floodplain Managers
- VT FEMA NFIP Page
River Corridor Resources
- VT River Corridors
- Flood Hazard and River Corridor Protection Procedure – This is set of procedures that the state will follow when reviewing projects under state programs such as Act 250 or municipally exempt activities.
- Flood Hazard Area & River Corridor Rule: activities exempt from municipal regulation
- ANR General Permit for Flood Hazard Areas & River Corridors – An ANR General Permit for activities exempt from municipal regulation in Flood Hazard Areas and River Corridors. These activities include state-owned and operated institutions and facilities, accepted agricultural and silvicultural practices, and power generating and transmission facilities regulated under 30 V.S.A. §§ 248 and 248a.
Flood and Water Data
- StreamStats USGS- Tool to get watershed sizes and discharges
- USGS Current Water Data for Vermont
- National Weather Service (BTV)
- Advanced Hydrologic Prediction Service for VT
- Automated River Flow Gauge – Ayers Brook (Randolph)
- Automated River Flow Gauge – Connecticut River (Hartford)
- Automated River Flow Gauge – Ottauquechee River (West Bridgewater)
- Automated River Flow Gauge – Waits River (East Orange)
- Automated River Flow Gauge – Wells River (Wells River)
- Automated River Flow Gauge – White River (West Hartford)
- NEW: Vtrans Flood Resilience Map: a web-based application that identifies bridges, culverts, and road embankments that are vulnerable to damage from floods, estimates risk based on the vulnerability, and criticality of roadway segments, and identifies potential mitigation measures based on the factors driving the vulnerability.