Floodplains - Definition: A land area adjacent to one or more rivers and streams and subject to recurring flooding. The boundary of this area is determined by the 100-year floodplain, as delineated by the Federal Emergency Management Agency. The term "100-year flood" is a statistical designation meaning there is a 1-in-100 (1%) chance that a flood this size will happen during any year.

During storms (whether 100-year or more frequent), floodplains serve to absorb and slow flood waters, and take up water-borne pollutants. Where maintained in a relatively natural state, these areas also help limit potential for erosion, downstream sedimentation, non-point-source pollution, and obstruction or alteration of the floodway. Floodplains are usually associated with “headwaters” (discussed below). As with headwaters, maintenance or establishment of stable, wooded vegetative cover in floodplain areas can help maintain both stream water quality as well as control flooding.

Headwaters - Definition: The land area or watershed that drains to “first-order streams,” which are the small streams that first define water flowing on the ground from rainfall, snowmelt, or springs.

Since first-order streams are the smallest streams in the greater stream system, they are significant beyond their size since they are sensitive to sediment from unprotected lawns, unswept roads, and construction sites. Other impacts include excess paving of and pollutant discharge within the headwaters of the watershed. Maintenance or restoration of wooded headwaters is especially important given the ability of wooded areas to slow and filter flows to the first-order stream, provide shade and water temperature regulation for the first-order stream, and supply food and cover for wildlife that use first-order streams.

Greenways - Definition: Corridors of land that serve as linkages among high priority natural resources or manmade features. They can be either land or water based and serve a variety of functions and benefits, including community revitalization and economic development, natural resource conservation, environmental protection, wildlife habitat, and migration.

Greenways provide opportunities to protect and manage wildlife, forests, and ecological systems by creating corridors that connect natural areas, making it possible for more varieties of plants to grow and for wildlife to access water and food by traveling along the greenway. There are many environmental benefits associated with creating natural resource-based greenways – air quality is improved by preserving trees that produce oxygen, water quality is protected, and noise and thermal pollution are reduced. Greenways are increasingly utilized as a focal point for land protection and land use strategies.

Woodlands - Definition: A tree mass or plant community in which tree species are dominant and tree branches form a complete or nearly complete canopy.

Woodlands support mature or maturing stands of trees that absorb large amounts of rainfall or snowmelt through their roots and/or allow the rainfall or snowmelt to infiltrate into the aquifer below. Woodlands are especially valuable along streams, providing cover and shade to aquatic life that lives and breeds in and near these areas. Most plants and animals which are native, and therefore ecologically significant to the mid-Atlantic, are adapted to life in or near woodlands. For example, many indigenous and beneficial species (e.g., pollinators), soil organisms, and natural predators (e.g., insect-eating birds) live and breed in woodlands. Most woodlands are pleasing to the eye and so have aesthetic value. Further, they function as natural barriers to unwelcome noise, strong winds, and unsightly views, as well as reduce temperature extremes and moderate evaporation. Woodlands can include areas where timber has been recently harvested and is being allowed to rejuvenate, as well as orchards and “old fields” (i.e., open fields supporting young shrubs and trees or even a more open woodland canopy). These latter areas provide similar functions to woodlands in terms of aesthetic value, groundwater recharge, and habitat for native plants and animals.