Chesapeake Bay Critical Area Act Glossary: Key Terms & Definitions for Developers and Consultants

Chesapeake Bay Critical Area Act Key Terms & Definitions

100-foot Buffer: An area that begins at the mean high water line of tidal waters, the edge of each bank of tributary streams, or the landward edge of tidal wetlands, and extends 100 feet landward. This buffer area provides a protective barrier to filter runoff and minimize adverse impacts of development on the Chesapeake Bay and its tributaries.

Accessory Structure: A structure that is detached from the principal structure, located on the same lot, and clearly incidental and subordinate to the principal structure. Examples include tool sheds, garages, and swimming pools.

Best Management Practices (BMPs): Conservation practices or systems of practices and management measures that control soil loss and reduce water quality degradation caused by nutrients, animal waste, toxins, and sediment.

Buffer Management Plan: A plan that shows the 100-foot Buffer and any proposed development, describes how the forested vegetation in the 100-foot Buffer will be established or enhanced, and outlines how the Buffer will be maintained in the future.

Chesapeake Bay Critical Area (Critical Area): All land and water areas within 1,000 feet beyond the landward boundaries of state or private wetlands and the heads of tides, as designated under the Critical Area Act.

Chesapeake Bay Critical Area Commission (CAC): The agency responsible for overseeing the development and implementation of local Critical Area programs, which are designed to foster more sensitive development activity along the shoreline of the Chesapeake Bay and its tributaries.

Critical Area Buffer Management Plan: A plan that details how forested vegetation in the 100-foot Buffer will be established and maintained, including provisions for replanting, controlling invasive species, and protecting trees during construction activities.

Critical Area Buffer Management Overlay (CBMO): An overlay zone that delineates the geographic area where specific buffer management strategies, such as reforestation and stormwater management practices, must be implemented to protect and enhance the 100-foot Buffer.

Development Activities: Human activities that result in disturbances to land, natural vegetation, or a structure, including construction or reconstruction of a structure, grading, and land clearing.

Forested Vegetation: Trees and other woody plants that grow in a contiguous fashion, creating a visual buffer and providing habitat for wildlife.

Growth Allocation: An allotment of additional land within the Critical Area that a local jurisdiction may use to create new Intensely Developed Areas (IDAs) or Limited Development Areas (LDAs), or to change the classification of an existing LDA to an IDA.

Habitat Protection Area: An area identified by the Department of Natural Resources as having plant or animal species that are threatened, endangered, or in need of conservation, or containing plant or animal communities that are ranked as rare or unique.

Impervious Surface: Any surface that does not allow stormwater to infiltrate into the ground, such as rooftops, sidewalks, driveways, and parking lots.

Intensely Developed Areas (IDAs): Areas where residential, commercial, institutional, or industrial development predominates, and where relatively little natural habitat occurs.

Limited Development Areas (LDAs): Areas that are currently developed in low or moderate intensity uses, and that contain areas of natural plant and animal habitats, as well as areas where the quality of runoff has not been substantially altered or impaired.

Local Critical Area Program: A program developed by a local jurisdiction to implement the goals and objectives of the Critical Area Act, including land use policies, zoning ordinances, and development regulations.

Mean High Water Line: The average level of high tides at a given location.

Mitigation: Actions taken to offset the adverse impacts of development activities on water quality, fish and wildlife habitat, or other resources protected under the Critical Area Act.

Nonconforming Use: A use of a structure or land that was lawfully established prior to the effective date of the Critical Area Act or local Critical Area program, but that no longer conforms to the current provisions of the program.

Resource Conservation Areas (RCAs): Areas characterized by nature-dominated environments, such as wetlands, surface waters, forests, and open space, and by resource-based activities, such as agriculture, forestry, fisheries, or aquaculture.

Riparian Habitat: Habitat found along the banks of streams, rivers, and other waterways, characterized by unique soil conditions and vegetation influenced by the presence of water.

Shore Erosion Control Measures: Structural or nonstructural methods used to control the erosion of shorelines, such as bulkheads, revetments, and living shorelines.

Special Buffer Area (SBA): An area of the 100-foot Buffer where existing patterns of residential, industrial, commercial, or recreational development prevent the Buffer from fulfilling its intended functions, and where development activities have significantly impacted water quality and habitat.

State Tidal Wetland: Any land under the navigable waters of the state below the mean high tide, affected by the regular rise and fall of the tide.

Steep Slopes: Slopes with a grade of 15% or greater that are within the Critical Area.

Tributary Streams: Perennial and intermittent streams that flow into tidal waters, not including ephemeral streams, which flow only after rainfall events.

Water-Dependent Facilities: Structures or activities that require location at or near the shoreline, such as ports, marinas, and fisheries.