Massachusetts Rivers Protection Act Glossary: Key Terms & Definitions for Developers and Consultants

Massachusetts Rivers Protection Act Key Terms & Definitions

Abutting land: Land that borders or touches the riverfront area, as defined in the Massachusetts Rivers Protection Act.

Actively growing vegetation: Vegetation that is actively growing and not dormant, as determined by the season and the species' natural growth cycle.

Bankfull discharge: The flow at which water begins to spill out of the channel and onto the floodplain.

Base flow: The portion of streamflow that is not directly attributed to precipitation runoff but is instead the result of groundwater seepage, springs, or other delayed sources.

Best management practices (BMPs): Methods, measures, or practices designed to prevent or reduce water pollution, including structural and nonstructural controls and operation and maintenance procedures.

Bordering vegetated wetland: A wetland that borders on a creek, river, stream, or brook and is in turn bordered by uplands.

Buffer zone: An area of land extending horizontally outward from the edge of a protected resource, such as a river or stream, that is subject to restrictions on development and other activities.

Channelization: The process of straightening, deepening, or widening a stream channel, often for flood control or navigation purposes.

Dredging: The removal of sediment or other material from the bottom of a water body.

Erosion control: Measures taken to prevent or mitigate the detachment and movement of soil particles by water, wind, ice, or gravity.

Filling: The depositing of any material that substantially impairs the natural flow of water, reduces the natural storage capacity of the land, or impairs the natural filtration capability of the land.

Floodplain: The area adjoining a river, stream, or watercourse that is subject to inundation during high water events.

Hydraulic capacity: The ability of a river, stream, or other watercourse to convey water without overflowing its banks.

Impervious surface: A surface that prevents or significantly impedes the infiltration of water into the underlying soil, such as a roof, road, sidewalk, or parking lot.

Intermittent stream: A stream that flows only at certain times of the year, generally in response to seasonal precipitation or groundwater discharge.

Land subject to flooding: An area that experiences temporary inundation of water during storms, high river flows, or other hydrologic events.

Mean annual high-water line: The average of the highest water levels achieved each year over a period of time, used to delineate the extent of a water body's influence on adjacent lands.

Natural stream flow: The flow of water in a stream that would occur in the absence of human interference or manipulation.

Non-point source pollution: Pollution that originates from diffuse sources and is carried by runoff, seepage, or atmospheric deposition, rather than from a specific point of discharge.

Ordinary high water mark: The line on the shore or bank established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, or the presence of litter and debris.

Perennial stream: A stream that normally flows year-round and is supplied by both surface runoff and groundwater discharge.

Point source pollution: Pollution that originates from a specific, identifiable source, such as a pipe, ditch, or other discrete conveyance.

Riparian area: The area of land adjacent to a river, stream, or other water body that is influenced by the presence of the water and its associated vegetation and wildlife.

Riverfront area: The area of land between a river's mean annual high-water line and a parallel line measured horizontally outward from the river, as defined in the Massachusetts Rivers Protection Act.

Runoff: The portion of precipitation, snowmelt, or irrigation water that flows over the land surface and is not absorbed into the ground, evaporated, or transpired by plants.

Sedimentation: The process by which particles of rock, sand, soil, or other material settle to the bottom of a water body, often as a result of erosion or runoff.

Stream order: A classification system that assigns a numeric order to streams based on their position within the overall drainage network, with the smallest headwater streams designated as first-order streams and the main river channel having the highest order.

Vernal pool: A temporary body of freshwater that provides essential breeding habitat for certain amphibians and invertebrates and typically dries out completely during the summer months.

Water-dependent use: A use that requires direct access to or location in water, such as a marina, boat launch, or hydroelectric facility, as defined in the Massachusetts Rivers Protection Act.

Wetland replication: The process of creating a new wetland area to replace a wetland that has been lost or altered due to development or other activities.