(1) Preservation of natural features. While removal of vegetation for necessary structures and yard space is allowed, the development will preserve natural topography and retain natural vegetation and trees to the maximum extent practicable in order to create the least erosion potential and handle adequately the volume and rate of surface water runoff.

(2) Natural drainage patterns. Natural drainage patterns shall be protected and incorporated into site design. Where natural drainage patterns are demonstrated to be adversely affecting a protective feature, such as an outcrop, significant tree or significant vegetation feature, drainage patterns may be altered in a manner which reduces the threat to such natural protective features provided such alteration does not create other flooding or erosion problems.

(3) Diversion of stormwater. In no case shall stormwater be diverted to another property.

(4) Natural features for stormwater recharge. Natural land features, such as shallow depressions, shall be used, whenever possible, to collect stormwater on site for recharge. Under no circumstances, however, shall such a feature be used if subsurface conditions cause a stagnant pool to develop.

(5) Minimize paving. Site designs shall minimize impervious paving and walks.

(6) Stormwater discharge to surface waters. Stormwater runoff shall not be directly discharged to surface waters, marshes and wetlands. Stormwater pollutants shall be attenuated by using holding ponds, sedimentation basins, perimeter berming, vegetated buffer areas and other measures that reduce flow velocity and increase storage time. In addition, any filtering devices constructed as part of the drainage system must be adequately maintained in order to function properly.

(7) Retaining wetland vegetation. All wetland vegetation shall be retained. Development should not disturb freshwater or tidal wetlands either by direct removal of vegetation or substrate or by the alteration of adjacent slopes that would undermine the stability of the substrate.

(8) Subsurface sediments. Subsurface sediments shall be maintained to provide structural support for the soils of the wetlands.

(9) Elevation of wetlands. The elevation of wetlands shall not be altered.

(10) Discharge of pollutants. Pollutants shall not be discharged into wetlands or other lands or waters but shall be handled in accordance with all applicable laws and regulations.

(11) Construction near wetlands. Construction shall not be located within 50 feet of the upland boundary of a freshwater or tidal wetland. This includes the introduction of impervious surfaces, roads, utility equipment and other infrastructure. An exception is made for a private dock, provided that no other opportunity for water access exists on the lot, except through wetlands. Wetland boundaries and the fifty-foot setback referred to in this subsection shall be identified on the plat as "conservation areas," and notes shall be placed on the plat and on all deeds that expressly prohibit accessory structures and uses in such areas.

(12) Fill not to encroach on watercourses. Fill shall not encroach on natural watercourses, constructed channels, wetlands or floodway areas. All fill shall be compacted at a final angle of repose which provides stability for the material, minimizes erosion and prevents settlement.

(13) Natural vegetative buffer. To the extent practicable, a natural vegetative buffer of 50 feet shall be maintained adjacent to surface waters and wetlands to absorb floodwaters and trap sediment.

(14) Trails and walking paths. Trails and walking paths along water bodies shall be sited and constructed so that they are not a source of sediment.

(15) Amount and velocity of runoff. The amount and velocity of runoff from a site after development shall approximate its predevelopment characteristics, such that the development shall result in zero net incremental discharge of runoff from the development site, or a decrease in the net incremental discharge of runoff from the development site through the use of green infrastructure as defined in § 360-4.14C. However, if the site is adjacent to coastal waters, stormwater shall be contained on-site, to the maximum extent practicable, to prevent direct discharge of runoff to coastal waters.

(16) Alteration of stormwater channels. Stream channels, natural floodplains and major drainage swales shall not be altered or disturbed in a manner which decreases their ability to accommodate and channel stormwater runoff and floodgates. If no practicable alternative to the location of driveways, pathways and similar surfaces within these areas exists, such facilities shall be sited and constructed to minimize and mitigate the amount or velocity of stormwater entering the swale.

(17) Time limits for installation. All permanent (final) vegetation and structural erosion control measures called for in approved plans shall be installed within the time limits specified by the Planning Board.

(18) The plan shall include a note stating who is responsible for maintaining any drainage system and shall conform to the requirements of § 360-4.12: Stormwater pollution prevention, Stormwater pollution prevention.

(19) Green infrastructure. To the maximum extent possible, the amount and velocity of runoff from a site should be reduced through the use of sustainable stormwater management techniques which retain runoff and enable infiltration on the site. Such techniques are hereby referred to as green infrastructure, as defined in § 360-4.14C.