ground water breaks out of a slope forming a sidehill seep. In this way they provide for flood control and prevention of flood damage. Alteration can result in the lateral displacement of retained water which may result in damage. Isolated Wetlands are areas where ground water discharges to the surface either by a rising water table or from a sidehill seep. Under some circumstances, surface water discharges to the ground water in these areas, particularly where they are underlain by pervious material. Contaminants introduced into such areas, such as septic system discharges, road salts, pesticides or herbicides, find easy access into the ground water. Where such areas are underlain by pervious material or covered by a mat of organic peat or muck, they are likely to be significant to the prevention of pollution. Isolated Wetlands providing Seasonal Wetland habitats are essential breeding sites for certain amphibians which require isolated areas that generally flood in the spring and/or summer, and are free of fish predators. Many reptiles, birds, and mammals also depend upon such Isolated Wetlands as a source of food.
Definition, Critical Characteristics and Boundary
Isolated Wetlands are wetlands that do not border on creeks, rivers, streams, ponds, lakes, or other water bodies. Some isolated depressions which hold standing water for extended periods of time, perhaps continuously, such as certain kettle holes too small to be called ponds or lakes, may be Isolated Wetlands.
Isolated Wetlands may occur in a depression or closed basin in otherwise flat topography. In these areas, water may pool above the surface at least once a year or may be contained in the top twenty-four (24) inches of soil. In addition, some Isolated Wetlands occur down slope of sidehill seeps, depending on the topography, soils and water regime.
In most cases, the vegetative community in Isolated Wetlands conforms to that specified in this Ordinance for Freshwater Wetlands.
The soils are annually saturated hydric soils as specified for Freshwater Wetlands.
The boundary of an Isolated Wetland shall be determined by one or more of the following, depending on the availability of information. Where more than one method is possible, that method leading to the largest area shall be used. The boundary of the Isolated Wetland shall be:
the line enclosing that area having a vegetative cover consisting of 50% or more of freshwater species, as defined in the Ordinance, or
the line enclosing the largest observed or recorded area of water confined in said area, or