§ 131-51 - Standards.

§ 131-51 - Standards.

The following standards shall be observed by the subdivider in the design, layout and engineering of the proposed subdivision in both the preliminary layout phase and the final plat phase:

  1. Except where modified herein, the Stormwater Management and Erosion Control Handbook for Urban and Developing Areas In New Hampshire prepared by the New Hampshire Department of Environmental Services, Rockingham County Conservation District, and USDA Soil Conservation Service, latest edition, will be used in design of all control measures.
  2. Stripping of vegetation, re-grading or other development shall be done in such a way that will minimize soil erosion first and capture potential sediment second.
  3. Whenever practical, natural vegetation shall be retained, protected and supplemented. Upon final grading, vegetation shall be re-established except where to be covered with hard surfaces.
  4. The disturbed area and duration of exposure shall be kept to a minimum. Disturbed areas not worked for two or more weeks shall be stabilized by applying and maintaining mulch. Disturbed areas not being worked for six or more weeks shall be stabilized by applying seeding, mulch, and tackifier, and maintaining vegetation.
  5. Upon permanent seeding, slopes steeper than 2.5 horizontal to 1 vertical (2.5:1) shall be stabilized with degradable erosion control matting designed to last 12 to 24 months. Upon permanent seeding, an organic tackifier shall be applied to mulch on disturbed slopes between 4:1 and 2.5.
  6. All disturbed work areas shall be stabilized prior to October 15.
  7. Sediment in the runoff water shall be trapped until the disturbed area is stabilized by the use of sediment basins or other acceptable methods. Drainage channels and earthen basins shall be stabilized with seed and mulch/erosion control fabric, sod, or riprap or other hard surfacing (where allowed) prior to directing flow to them.
  8. The inlet to subsurface infiltration devices shall be plugged until the vegetation is established in the areas tributary to the devices.
  9. Provide a construction sequence on the plans, including the earthwork and flow diversion sequence as well as the timing for the installation of the erosion control measures.
Standards.

part number

131-51