(A) The town contains and is bounded on the north and northwest by mountains and hills, which contain soils that range in depth, including very thin soils.
(B) Land-disturbing activities on high elevation, steep-slope mountain sides potentially threaten the public health, safety, welfare and economic progress of the town.
(C) The land-disturbing activity has the potential to cause the following:
(1) Endanger the quality of surface water by increasing erosion, stream sedimentation and stormwater runoff;
(2) Induce landslides;
(3) Adversely affect ground water due to the difficulty of providing proper sewage disposal and mitigating the potential for rainwater infiltration;
(4) Damage the habitat of some species of wildlife (plants and animals); and
(5) Detract from the mountain's scenic and natural beauty, which is vital to the recreation and tourism industry of the town.
(D) The Town Council finds the following.
(1) Steep hillsides are inherently unstable.
(2) Changes to slopes due to undermining by humans, flowing rivers, heavy rains, or the focusing of stormwater runoff by human built channels or storm drain outlets can cause erosion and/or landslides. Soil slips, which cause avalanche-style failures, as well as slower moving earth flows can occur on slopes of 20% or greater. Serious erosion can occur on much shallower slopes; however, steeper slopes are far less forgiving of construction errors than are shallower slopes.
(3) When steeper slopes fail, the failures can have disastrous consequences. Development can result in the alteration of land surfaces that can contribute to slope destabilization. Alterations that have the potential to further the instability of slopes include placing fills on top of marginally stable slopes, including organic matter such as tree limbs in the fill, cutting slopes at too steep of an angle, undermining the toe of a slope, redirecting storm water runoff in a way that artificially concentrates flows onto portions of the landscape that are not prepared to receive the concentrated flows, removing vegetation, and adding water to the slope by means of hillside septic systems or by means of inadequately supplying storm water drainage systems. All of these factors work together and can cumulatively decrease the stability of slopes and eventually lead to disaster. Landslides and other slope failures pose a variety of hazards to both life and property.
(4) Hillside development, if unregulated, can take place at the expense of environmental concerns. Stormwater runoff from humanly altered slopes is greater in both quantity and velocity than it would be from naturally graded and vegetated ground. Preserving existing vegetation reduces erosion by maintaining roots, which increase infiltration and bind soils. Vegetation also reduces the velocity of raindrops and slows the velocity of surface water flow by increasing the roughness and/or friction of the ground, thereby increasing groundwater recharge. Constructing hillside roads involves cuts in the upslope side and fill in the down slope side. Such cuts and fills are often much wider than the minimum required road right-of-way and can be more susceptible to failure.
(5) Hillsides and ridge lines are unique vegetation communities and wildlife habitats. Hillsides in developing areas are often the last remaining natural areas and are the final refuges for many species of wildlife. Development needs to be sensitive to the hillside's function of providing biodiversity.
(6) Hillsides have aesthetic value to the town and its surrounding areas and contribute to the community's sense of identity, as well as its tourism economy. Prominent mountains, peaks, hills and ridges have significance as identifiable landmarks to area residents. Hillside development, if unregulated, can take place at the expense of aesthetic concerns. Hills and ridges are highly visible from surrounding areas.
(7) Vegetation clearances and landform grading practices, if unregulated, can upset the natural shape of hills. The bulk, shape, height and color of buildings can contrast with the natural landscape if unregulated and thus intrude on the natural character of the landform. Regulations are needed to ensure that buildings and structures blend in with the natural environment through their placement on the land, shape, materials and colors.
(Ord. passed - -2008)