Lands that Flood

Includes Floodplains, Bordering Land Subject to Flooding, Isolated Land Subject to Flooding and Land Subject to Coastal Storm Flowage

Land Subject to Coastal Storm Flowage
Defined in the Wetlands protection Act as follows:
  • Land Subject to Coastal Storm Flowage means land subject to any inundation caused by coastal storms up to and including that caused by the 100-year storm, surge of record or storm of record, whichever is greater.
  • Information on the extent of Land Subject to Coastal flooding is available from the Flood Insurance Rate Maps published by the Federal Emergency Management Agency (FEMA). These maps can be viewed (and copied) in the Conservation Commission office.

Bordering Land Subject to Flooding


Land that is flooded when the water level rises in adjacent lakes, ponds or streams. (source-A Guide to Understanding and Administering the Massachusetts Wetlands Protection Act by Elizabeth Colburn, published by Massachusetts Audubon Society)

Almost every water body, no matter how small, will have bordering land subject to flooding associated with it.

The State Wetlands Protection Act defines Bordering Land Subject to Flooding as follows:
  • An area with low flat topography adjacent to and inundated by flood waters rising from creeks, rivers, streams, ponds or lakes." The boundary of Bordering Land Subject to Flooding is the 100-year floodplain. It extends from the outer edge of a bank or Bordering Vegetated Wetland." (10.57 (2)(a)1-3)
  • For most major bodies of water the 100-year flood elevation has been determined by the National Flood Insurance Program and will be shown on copies of the Flood Insurance Rate Maps published by the Federal Emergency Management Agency (FEMA). These maps are available for viewing or copying in the Conservation Commission office. However when the FEMA map does not state a flood elevation floodplain boundaries on controversial sites may need to be determined by hydrologic calculations.

Isolated Land Subject to Flooding


Land that floods as a result of surface runoff or groundwater discharge, not as a spillover from a water body (Colburn).

The Massachusetts Wetlands Protection Act defines Isolated Land Subject to Flooding as follows:
  • Isolated Land Subject to Flooding is an isolated depression or a closed basin which serves as a ponding area for run-off or high ground water which has risen above the ground surface. Such areas are likely to be locally significant to flood control and storm ground damage prevention. Isolated land subject to flooding is without an inlet or outlet. It is an area which at least once a year confines standing water to a volume of at least one-quarter acre-feet and to an average depth of at least six inches.
  • The boundary of Isolated land Subject to Flooding is the perimeter of the largest observed or recorded volume of water confined in said area.

Still Confused ?


If you are still confused as to whether your property or Proposal contains any of the above areas of land that flood? Stop by the Conservation Commission Office and we can help you.