Subdivisions and land developments shall be designed to achieve the general goals or outcomes that are listed in this section.
A. Minimize damage to the environment. All subdivisions and land developments shall be designed to minimize environmental damage by carefully fitting the subdivision or development to the natural environment of the site.
(1) Minimize grading. Roads, building sites, and lots should be laid out in a manner that will minimize disturbance of the land. Roads should generally follow existing contours, where doing so will minimize cuts and fills. Naturally level areas should in general be utilized for building sites. Clustering of development on less steep areas of the site is strongly encouraged, as an alternative to mass grading.
(2) Protect steep slopes. Wooded hillsides are important environmental and aesthetic resources of Allegheny County. Development should be located to avoid disturbance of steeply sloped areas and to preserve the visual character of wooded hillsides.
(3) Protect watercourses and wetlands. Watercourses are the county's natural drainage ways for the conveyance of surface waters, including runoff and flood waters. Streams, land bordering streams, and wetlands provide habitat for aquatic and terrestrial plants and animals and may function as wildlife corridors. The County's larger streams and rivers are primary elements of the visual character of the county and are also important resources for recreation and commerce. Development should be designed to preserve and protect the county's watercourses and wetlands so that they can continue to serve all of these functions.
(4) Preserve mature trees and woodlands. The excessive cutting of trees and clearance of woodlands in conjunction with subdivision and development of land causes soil erosion, increased runoff, loss of habitat, and diminution of one of the county's most significant visual resources: the wooded hillsides that are so prominent throughout the area. Except for regulated commercial timbering operations, the cutting of mature trees and clearance of woodland should be allowed only after final approval of a plan for subdivision or land development, and then only to the extent required for the construction of roads, utilities, and buildings. Total clearance of vegetation and mass grading of development sites shall be prohibited.
(5) Protect other identified natural resources. Special care must be taken in the design and construction of subdivisions and land developments to protect habitats in which rare or endangered plants or animals are found and other ecologically important sites.
(6) Protect historic, architectural, and archeological resources. Sites containing structures of historic or architectural significance should be designed to preserve, and reuse such structures. Archeological resources must be protected in accordance with applicable state regulations.
(7) Protect the quality of the county's air and water. All land development shall comply fully with federal, state and county laws and regulations concerning air and water pollution.
B. Avoid hazardous development. Where hazardous or potentially hazardous features are present on proposed development sites, the design of subdivisions and land developments shall consider such features. Extra precautions shall be required to ensure that development will be safe and that the public health and welfare will be protected. Development shall not be approved unless safety is ensured.
(1) Landslide-prone areas. In areas where soils or underlying geology may be unstable, geotechnical investigation shall be required to ensure the safety of any proposed disturbance.
(2) Undermined areas. In areas where mining has occurred in the past, subsidence risk assessments may be required to establish that proposed development will be safe.
(3) Flood-prone areas. In undeveloped areas of the county, construction in flood-prone areas should be avoided entirely. In areas, where floodplains have been developed in the past, new development shall be in accordance with municipal floodplain regulations, enacted in accordance with the Pennsylvania Flood Plain Management Act.
(4) Contaminated sites. In order to protect the public health, no subdivision or development of land in areas which may have been contaminated by former industrial or other uses shall be approved unless the site has been made safe for development. Development of contaminated sites shall be limited to uses which will not pose health risks for site occupants.
(5) Areas exposed to aircraft noise or hazards. Subdivisions and land developments in areas of the county where airport-related noise is high or where aircraft landings and takeoffs can be endangered by vertical obstructions or other hazards shall ensure that development does not reduce the ability of the airport to function safely and efficiently. Conversely, the safety of development and health and welfare of occupants should not be compromised because of proximity to airports.
C. The general layout of subdivisions and land development should respect the natural resources of the site, the character of the surrounding area, and be suitable for the intended uses. The design of blocks and lots shall comply with the zoning requirements of the municipality and should provide suitable sites for buildings. The design of subdivisions and land development should consider the topography and other natural features of the site, requirements for safe and convenient pedestrian and vehicular circulation, and the character of surrounding development. Subdivisions and land developments should be compatible with municipal, county, and regional Comprehensive Plans and components thereof.
D. Land development shall include landscaping which is designed to improve community appearance, to contribute to the environmental quality and livability of new development areas, and to mitigate the negative impacts of development upon other areas of the community. Uses and structures shall be sited to minimize adverse impacts from or upon adjoining uses. Landscaping and bufferyards should be designed to reduce unavoidable impacts and to augment the natural features of the site.
E. Provide a full range of improvements in subdivisions and land developments as required ensuring the public health, safety, and welfare and the creation of desirable communities for living, working, and recreation.
(1) Water. A safe and sufficient supply of potable water shall be provided for every subdivision and land developments, in accordance with applicable regulations of the commonwealth and county. New development shall not degrade the quality of potable water supplies.
(2) Sanitary sewage facilities shall be provided in accordance with applicable regulations of the commonwealth and county.
(3) Stormwater management. Every subdivision and land development shall manage stormwater flows in accordance with the Pennsylvania Storm Water Management Act. All development located in watersheds for which watershed stormwater management plans have been adopted shall comply with all requirements of the watershed plan.
(4) Other public utilities, shall be provided or available to every subdivision and land development, including electricity, natural gas, telephone, and where accessible, cable TV.
(5) Public and community services. All new development should have access to a full range of community services and facilities, such as public safety and emergency services, schools, libraries, and recreation.
(6) Transportation facilities. The design and constructions of subdivisions and land developments should include transportation facilities that will provide access to all lots, buildings, and open spaces intended for use by people. Transportation facilities that are developed in subdivisions and land developments should be designed as parts of the larger system of transportation facilities which serve the community. Transportation facilities may include streets, public transportation, sidewalks, bikeways, and multipurpose trails for nonmotorized transportation.