(a) Replication of Bordering Vegetated Wetland
(1) Preamble. There is at present no published scientific evidence to substantiate that the process of wetland replication is a viable, realistic, or reasonable
substitute for a mature, established wetland. Thus, the Commission's approach to replication will be cautious until such evidence is available. The following standards are established in an attempt to insure the viability and success of any replication project in the Town of Scituate.
(2) The Commission will make a determination as to whether the proposed wetland replication is necessary. The justification for the destruction of a wetland must be clear and convincing that there is no available alternative.
(3) The edge of the proposed replicated wetland must be at least 100 feet from any property line unless written permission is granted by the adjoining property owner.
(4) Area. Within the Water Resource Protection District, no Bordering Vegetated Wetland may be destroyed. In other areas up to 2500 square feet may be destroyed with replication at least twice that of the area lost.
(5) Submittals. The applicant must provide the Commission with;
(1) competent and complete analysis and survey of the area being destroyed, drained, or filled; and the area selected for replication as it exists before replication;
(2) A replication plan including a complete hydrological, geological, chemical, and biological survey and analysis.
(3) A complete record of the area being replicated and the area being filled.
This shall include, but not necessarily limited to, photographs, soil
profiles, water elevations, and vegetative cover for the area before, during and after replication.
(6) The replication area must be the same type of wetland in form and vegetative composition and hydrologically connected to the filled, dredged, or destroyed wetland.
(7) The applicant must show that alteration of said area for new replication will have no adverse effect on: flood protection, protection of private or public water supply, wildlife habitat, other protective vegetation and/or adjacent properties and habitats.
(8) The new wetland must be created before the existing wetland is filled, drained or destroyed (unless material from the existing wetland is to be used in the creation of the new wetland). Completion shall include at minimum the creation of a natural wetlands soil profile, grading to natural water level and planting of species as conditioned by the Commission. In no case may other activities be undertaken until the replication is complete.
(9) The applicant must monitor the replicated wetland for a minimum of 5 years and submit annual reports to the Commission. These reports must assess the soil, water, and plant conditions of the replicated wetland. The applicant may be required, on an annual basis, to remedy any deficiencies at the replication site.
(b) Limited Access Projects
(1) Preamble. Limited access projects involve the construction and maintenance of a new roadway or driveway, through a resource area, of minimum legal and
practical width acceptable to the Planning Board, where reasonable alternative means of access from a public way to an upland area of the same owner is unavailable. Such roadway or driveway shall be constructed in a manner which does not restrict the flow of water or the recharge of groundwater on-site.
(2) Area. When limited access projects are permitted. A minimum replication area of twice that of the area being lost will be required.
(3) Submittals. The applicant must provide the Commission with:
(1) Written documentation from the Planning Board that the new roadway or driveway is of minimum legal and practical width acceptable to the Planning Board.
(2) Documentation of alternative accesses requested and the environmental or other reasons for denial by the Planning Board.
(3) Presentation of alternative ways of constructing and or obtaining access (e.g.: bridge, pilings), and design of access (e.g.: minimum width, height, length).
(4) Presentation of methods explored to minimize wetlands impacts and rationale for selected design decision. Applicants should explore the use of piling supports, bridging, box culverts with vertical walls, etc.
(5) Construction methodology must be described in full. Proposals for coffer damming, type of equipment, size of equipment, etc. should be included.
Construction area shall be the limits of the roadway.
(c) Detention Basins
Preamble. For the purposes of these regulations, a detention basin is defined as a man-made, basin-like flood control structure which is designed to collect stormwater runoff and to detain it for a specified period of time during major storm events. It also is designed to minimized contaminants from leaving the project site.
The purpose of these regulations is to establish guidelines and standards for the design and construction of detention basins. Given variations in soil conditions and
assumptions, calculation formulas and construction details can be applied to the majority of designs.
A detention basin is not the only method of controlling excess runoff from developments. Before considering the use of a detention basin, other methods of controlling runoff including, but not limited to, stormwater leaching pits and natural or man-made swales shall be investigated. A detention basin should be used only if alternate, low-maintenance methods are not feasible. The applicant shall demonstrate, through a preponderance of credible evidence, that alternative solutions have been seriously considered.
Detention basins will not be allowed within a Resource Area or in the Buffer Strip.