5.2 BORDERING VEGETATED WETLANDS (WET MEADOWS, MARSHES, SWAMPS AND BOGS)
Bordering Vegetated Wetlands are likely to be significant to: public or private water supply,
ground water supply, flood control, storm damage prevention, prevention of pollution, wildlife habitat, water quality control, water pollution, and erosion and sedimentation control.
The plants and soils of Bordering Vegetated Wetlands remove or detain sediments, nutrients (such as nitrogen and phosphorous) and toxic substances (such as heavy metal compounds) that occur in run-off and flood waters. Some nutrients and toxic substances are detained for years in plant root systems or in the soils. Others are held by plants during the growing season and released as the plants decay in the fall and winter. This latter phenomenon delays the impacts of nutrients and toxins until the cold weather period, when such impacts are less likely to reduce water quality.
Bordering Vegetated Wetlands are areas where ground water discharges to the surface and where, under some circumstances, surface water discharges to the ground water. The profusion of vegetation in Bordering Vegetated Wetlands acts to slow down and reduce the passage of flood waters during periods of peak flows by providing temporary flood water storage and by facilitating water removal through evaporation and transpiration. This process reduces downstream flood crests and resulting damage to private and public property. During dry periods the water retained in Bordering Vegetated Wetlands is essential to the maintenance of base flow levels in rivers and streams, which in turn is important to the protection of water quality and water supplies.
The Act defines freshwater wetlands by hydrology and vegetation. Hydrology is the driving force which creates wetlands, but it is a transient, temporal parameter. The presence of water at or near the ground surface during a significant portion of the year supports, and in fact promotes, the growth of wetland indicator plants. Prolonged or frequent saturation or inundation also produces hydric soils, and creates anaerobic soil conditions that favor the growth of wetland indicator plants. Hydric soils are direct indicators of long-term hydrologic conditions and are present throughout the year.
Wetland vegetation supports a wide variety of insects, reptiles, amphibians, small mammals and birds
which are a source of food for important game fish. Bluegills (Lepomis macrochirus), pumpkinseeds
(Lepomis gibbosus), yellow perch (Perca flavescens), rock bass (Ambloplites rupestris) and all trout species feed upon nonaquatic insects. Chain pickerel (Esox niger) and northern pike (Esox lucius) feed upon small mammals, snakes, nonaquatic insects, birds and amphibians.
Wetland vegetation provides shade, which moderates water temperatures important to fish life. Wetlands
flooded by adjacent water bodies and waterways provide food, breeding habitat and cover for fish. Fish
populations in the larval stage are particularly dependent upon food provided by over-bank flooding which
occurs during peak flow periods (extreme storms) because most river and stream channels do not provide
sufficient quantities of the microscopic plant and animal life required for food. Bordering vegetated wetlands are probably the Commonwealth’s most important inland habitat for wildlife. The hydrologic regime, plant community composition and structure, soil composition and structure, topography, and water chemistry of bordering vegetated wetlands provide important food, shelter, migratory and overwintering areas, and breeding areas for many birds, mammals, amphibians and reptiles. A wide variety of vegetated wetland plants, the nature of which are determined in large part by the depth and duration of water, as well as soil and water composition, are utilized by varied species as important areas for mating, nesting, brood rearing, shelter and food (directly and indirectly). The diversity and interspersion of the
vegetative structure is also important in determining the nature of its wildlife habitat. Different habitat characteristics are used by different wildlife species during summer, winter and migratory seasons. Although the vegetational community can often be analyzed to establish an accurate wetland boundary, sole reliance on the presence of wetland indicator plants can be misleading because some species thrive in both uplands and wetlands. Gently sloping areas often produce large transitional zones where the vegetational boundary is difficult to delineate. Hydrology can supplement vegetative criteria to enhance the technical accuracy, consistency, and credibility of wetland boundary delineations, and are especially useful for analyzing disturbed sites.
5.2.1 Definition, Critical Characteristics and Boundary
Bordering Vegetated Wetlands are freshwater wetlands which border on creeks, rivers, streams,
ponds and lakes. The types of freshwater wetlands are wet meadows, marshes, swamps and bogs.
Bordering Vegetated Wetlands are areas where the soils are saturated and/or inundated such that they
support a predominance of wetland indicator plants. The ground and surface water regime and the
vegetational community which occur in each type of freshwater wetland are specified in M.G.L. c. 131,
§ 40. The physical characteristics of Bordering Vegetated Wetlands, are critical to the protection of the interests identified. The boundary of Bordering Vegetated Wetlands is the line within which 50% or more of the vegetational community consists of wetland indicator plants and saturated or inundated conditions
exist. Wetland indicator plants shall include but not necessarily be limited to those plant species identified
in the Act. Wetland indicator plants are also those classified in the indicator categories of Facultative,
Facultative+, Facultative Wetland-, Facultative Wetland, Facultative Wetland+, or Obligate Wetland in
the National List of Plant Species That Occur in Wetlands: Massachusetts (Fish & Wildlife Service,
U.S. DEP of the Interior, 1988 or more current list) or plants exhibiting physiological or morphological adaptations to life in saturated or inundated conditions.
Areas containing a predominance of wetland indicator plants are presumed to indicate the presence of saturated or inundated conditions. Therefore, the boundary as determined by 50% or more wetland indicator plants shall be presumed accurate when:
1. All dominant species have an indicator status of obligate, facultative wetland+, facultative
wetland, or facultative wetland- and the slope is distinct or abrupt between the upland plant
community and the wetland plant community;
2. The area where the work will occur is partly or wholly within the buffer zone; or
3. The issuing authority determines that sole reliance on wetland indicator plants will yield
an accurate delineation.
When the boundary is not presumed accurate by the Commission, or to overcome the presumption, credible evidence shall be submitted by a competent source (a registered, certified wetlands scientist). The Commission will evaluate vegetation and indicators of saturated or inundated conditions if submitted by a credible source, or may require credible evidence of saturated or inundated conditions when determining the boundary. Indicators of saturated or inundated conditions sufficient to support wetland indicator plants shall include one or more of the following:
1. Groundwater, including the capillary fringe, within a major portion of the root zone;
2. Observation of prolonged or frequent flowing or standing surface water;
3. Characteristics of hydric soils.
Where an area has been disturbed the boundary is the line within which there are indicators of saturated or inundated conditions sufficient to support a predominance of wetland indicator plants, a predominance of wetland indicator plants, or credible evidence from a competent source that the area supported or would support under undisturbed conditions a predominance of wetland indicator plants prior to the disturbance.
The Commission may require restoration in areas where the disturbance occurred without appropriate permitting and prior review and approval.
Where a proposed activity will remove, fill, dredge, build upon, degrade, discharge into or otherwise alter a Bordering Vegetated Wetland, the issuing authority shall presume that such area is significant to the interests identified.
This presumption may be overcome upon a clear showing that the Bordering Vegetated Wetland does not play a role in the protection of said interests. In the event that the presumption is deemed to have been overcome, the issuing authority shall make a written determination to this effect, setting forth its grounds.
5.2.2 General Performance Standards
Any proposed work in a Bordering Vegetated Wetland shall not destroy or otherwise impair any portion of said area.
The Commission may issue an Order of Conditions permitting work which results in the loss of up to 5000 square feet of Bordering Vegetated Wetland when said area is replaced in accordance with the general conditions found in Chapter 7 of these regulations – Wetland Replication, and any additional, specific conditions the Commission deems necessary to ensure that the replication area will function in a manner similar to the area that will be lost. This allowance is at the discretion of the Commission on a case-by-case basis when no other alternatives are possible. Disturbing 5000 square feet of Bordering Vegetated Wetland is the maximum allowable under extreme conditions and not the right of an applicant or landowner.
No project may be permitted which will have any adverse effect on specified habitat sites of rare vertebrate or invertebrate species, as identified by procedures established under 310 CMR 10.59, Estimated Habitat for Rare Wildlife.
Any proposed work shall not destroy or otherwise impair any portion of a Bordering Vegetated
Wetland that is within an Area of Critical Environmental Concern designated by the Secretary of
Environmental Affairs.
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