CHAPTER I ENVIRONMENTAL PROTECTION AND HAZARD CONTROL Part 1. "A half-century ago Pittsburgh was in the headlines...because environmentally it was `hell with the lid off'." --Remaking Cities conference brochure, 1988. Pittsburgh and Allegheny County have experienced a major transition in their economy -- from one dominated by iron and steel manufacturing -- to a diversified economy that includes higher education, health services, and advanced technology industries. The transition has been accompanied by dramatic improvement in the quality of the County's air and water and by the elimination of much physical blight, so that today visitors marvel at the breath-taking river views, wooded hillsides, and large parks. The physical environment in the County -- once described as "hell with the lid off" -- is now widely recognized as one of the nation's most beautiful urban settings. As land development continues, however, the environmental resources that are so valued are also threatened. Wooded hillsides have been cleared and leveled; wetlands have been filled; and streams have been muddied. Moreover, improper development continues to cause flooding, landslides, and subsidence. "Environmental protection" is a broad concept that continues to expand with increasing public awareness, concern and regulation of various forms of hazards, pollution and sensitive or endangered resources. The growing concern of Pennsylvania residents about their environment resulted in 1971 in an amendment to the state constitution which declares the right of the people "to clean air, pure water, and to the preservation of the natural scenic, historic, and aesthetic values of the environment...." The Department of Environmental Resources was created in the same year to consolidate the increasing environmental protection responsibilities of numerous state agencies. More recently, in response to rapid growth in rural and suburban areas of Pennsylvania and the loss of agricultural land, wetlands, and other environmentally sensitive areas, the Pennsylvania House of Representatives in 1990 authorized the appointment of a House select committee to examine issues relating to land use, development, and growth management. Other legislation authorizes environmentally oriented action. Pennsylvania law (53 P.S. S 11401, et seq.) allows municipalities to enter into special agreements called Environmental Improvement Compacts and establish, separately or jointly with other municipalities, an Environmental Advisory Council to advise local officials on matters dealing with protection, conservation, management, promotion and use of natural resources. Plans, recommendations, or studies prepared by environmental advisory councils or local planning commissions can be invaluable in determining whether zoning and subdivision controls are needed to protect important resources. Zoning regulations traditionally establish restrictions on the size, intensity and location of land development. In 1988, the Pennsylvania legislature broadened the zoning powers of municipalities to regulate the environmental impacts of development as well. (See MPC S604, clause (1)). Local powers to regulate subdivisions and land development for environmental purposes are grounded in a variety of separate statutes governing stormwater management, erosion control and wetlands. Manuals promulgated by the Department of Environmental Resources are useful sources for municipalities. Allegheny County prepares model storm water management ordinances for municipalities in watersheds for which plans have been adopted. Some of the model regulations included in the second part of this Chapter are substantively more restrictive than the minimum state or federal standards. For example, the flooding patterns in some parts of Allegheny County indicate that flood insurance maps may be outdated. Therefore, municipalities are urged to restrict development in these areas, rather than allow it with minimum flood-proofing measures (as federal and state law would allow). After decades of experience in administering some environmental laws, it is apparent that stricter standards are needed in some cases. This Handbook has been prepared to help those municipalities who wish to do more than the minimum. 1. Planning Ahead Natural resource protection starts with information gathering and identification of potentially sensitive areas (through natural resources inventories, carrying capacity analysis or environmental impact statements). Once important natural resources have been identified, the techniques which are most appropriate for a particular municipality will depend in large part on the level of commitment for protecting a particular resource (such as trees, hillsides, or rivers), and the capabilities of planning commissioners, zoning administrators and staff to administer and enforce natural resources regulations. The comprehensive planning process is the most efficient and effective means of collecting and analyzing information as a basis for public regulation of natural resources. Regulations are only one way that planning policies can be implemented. Others include inventorying, monitoring, and acquisition of significant resources, education and policy making, conservation easement and other tax-benefit programs, and purchase or transfer of development rights programs. a. Natural Resource Inventories (1) Description. Natural resource inventories are usually performed for an entire county or municipality as a step in the preparation of a community's comprehensive plan. The inventory provides information necessary to identify general areas where future growth and development should be limited or restrained. If possible, such inventories should be detailed enough to be a basis for reviewing specific development proposals. The scope and design of a natural resources inventory should reflect the goals and values of the community, as clearly articulated in the community's comprehensive plan or land use regulations. For example, a municipality might establish a goal of protecting steep slopes from development in order to prevent landslides. The inventory should describe the characteristics of landslide-prone areas to facilitate more in-depth on-site evaluations at a later time. The natural resources inventory process can be expensive and require staff trained in geologic, hydrologic and environmental analysis. The size and sophistication of the staff may limit the types of data that will be useful, the geographic units on which data are measured, and the methods by which the information can be analyzed, interpreted and presented. Land trusts and other non-profit conservation organizations can be an important source of information and assistance in this process. (2) Examples of Use in Other Locations. Aspen, Colorado is an example of a community in another part of the country that restricts development based on consideration of natural features, such as steep slopes, stream valleys, and mountain views. Aspen's Land Use Regulations contain special standards for development in Environmentally Sensitive Areas (ESA's). ESA's are: (1) steep slope areas (located above or just below "the green line" or 8040 feet above mean sea level), (2) "stream margins," or areas near the Roaring Fork River, its tributary streams or flood plains, and (3) designated mountain view planes. In areas just below or above the "green line," no development is permitted unless the Aspen Planning and Zoning Commission finds that: *the site is suitable for development considering its slope, ground stability characteristics, including mine subsidence and the possibility of mud flow, rock falls and avalanche dangers; *the parcel is free of hazardous or toxic soils, or if present, that such soils are stabilized or removed; *the proposed development will have no significant adverse impact on the natural watershed, runoff, drainage, soil erosion, water quality or air quality; and *the proposed development is designed to minimize the need for roads, cutting and grading, and will maintain open space and preserve the mountain as a scenic resource. Development is only allowed to the extent that the natural geologic features can safely accommodate it. The same concept is implemented through special development review standards for "stream margins." (3) Use in Allegheny County. Municipalities in Allegheny County could utilize their planning commissions and environmental advisory councils to inventory natural resources and make recommendations regarding their protection. Though only a few Allegheny County municipalities currently have environmental advisory councils, there is no reason why other municipalities could not adopt them or join with other municipalities in forming a regional environmental council. There are a number of information sources available to assist municipal environmental councils or staff in conducting natural resources inventories. Allegheny County is in the process of collecting environmental data for the County comprehensive plan. It has also undertaken a major geographic information system (GIS) program. Data for certain natural hazards, such as undermined areas, landslide-prone soils, steep slopes and wetlands are available through the Allegheny County Planning Department. When complete, the County's geographic information system should be very useful to municipalities in identifying and inventorying important natural features. Several of Allegheny County's municipalities also have well-developed environmental protection programs that may be useful as models to other municipalities. For example, Fox Chapel requires an on-site natural features assessment as part of its land development review process. On-site assessments are a topic that is covered in more depth in the "environmental assessments" section of this Chapter. b. Carrying Capacity Analysis (1) Description. "Carrying capacity" is an ecological term that describes the ability of a natural system to support a particular population, such as a particular animal population. Carrying capacity planning involves identifying natural and/or man-made limiting factors, and then managing growth so that available capacity is not exceeded. Carrying capacity planning may take the form of land use regulations, which limit the cumulative amount of future development according to capacity limits, or may function merely as a monitoring and warning system for public decisionmaking. (2) Examples of Use in Other Locations. Carrying capacity analysis has most commonly been used in coastal or island communities with clear natural boundaries. With the success of early experiments, there has been increasing interest in expanding the use of carrying capacity analysis to inland areas. The Florida Keys and Sanibel Island, Florida, are two classic examples. The Florida Keys (Monroe County). Temperature and the existence of fresh water or the absence of salt water are significant limiting factors for the distribution of plants and animals in the Florida Keys. Similarly, the capacity of U.S. 1, the Keys' only vehicular link to the mainland, is a limiting factor when human tolerance of traffic congestion reaches its upper bounds and the cost and effectiveness of alternatives (boats and aviation) are unacceptable. The Monroe County land development code, which covers the Keys, establishes special environmental performance standards (including habitat analysis for designated areas containing endangered plant or animal species) and development standards pertaining to adequate public facilities (including roads, solid waste, potable water and schools, and surface water management and wastewater treatment). These standards were devised to ensure that the "carrying capacity" of the islands was not exceeded. Sanibel Island, Florida. Sanibel is a low-lying barrier island just off the Gulf Coast of Florida. In 1963, a 2-1/2 mile causeway was extended to the island, setting off accelerated growth and development. A decade later the citizens of Sanibel succeeded in passing a referendum to incorporate the island as a city with powers to plan for its own future. A comprehensive plan was drafted based on Ian McHarg's environmental constraint mapping approach, and is one of the earliest examples of applied carrying capacity planning. Chief among the limiting factors for the island was hurricane evacuation. Carrying capacity was derived from a careful analysis of the capacity of the island's access system available for evacuation after a hurricane warning system was posted. The narrow, two-lane causeway to the mainland was determined to have an evacuation capacity of approximately 650 vehicles per hour. That number of vehicles was then translated into a total number of households that could be accommodated. The City determined that its character could only be maintained if the total number of residential and hotel housing on the island were limited to 7,000-9,000 dwelling units, far less than the 35,000 dwelling units that Lee County's zoning would have permitted. (3) Use in Allegheny County. Carrying capacity analysis has not yet been overtly used in the Pittsburgh region as a basis for managing growth. While municipalities in Allegheny County are unlikely to make disaster evacuation a basis for limiting development, there are a number of other potential uses for such analyses, such as cooperative traffic management. The City of Pittsburgh, for example, has used road capacity limitations as one basis for establishing the allowable FAR in some of its Specially Planned Districts, including Herrs Island (being developed as Washington's Landing) and a riverfront site (being developed as Pittsburgh Technology Park). 2. Zoning Regulations A variety of zoning approaches to environmental protection have evolved over the past two decades. Special zoning districts known as "overlay districts" have been widely used to provide extra controls in flood plains, steep slopes and other areas. Another, more comprehensive approach is a technique known as "site capacity analysis." This approach measures the development capacity of a site rather than the carrying capacity of a major bridge or highway. Protected areas are subtracted out before calculating the maximum number of dwelling units or square feet of commercial or industrial space that are permitted. Clustering and other types of development regulations can prohibit development of sensitive areas but do not reduce the density that would otherwise be allowed. With so many options available, municipalities may be tempted to adopt overlapping or duplicative regulations. Unnecessary overlap of environmental regulations should be avoided. Use of a more comprehensive approach, such as environmental assessments or site capacity analysis eliminates the need for extra regulations dealing with specific environmental protection issues. All municipalities in Allegheny County which have flood-prone areas already have flood plain regulations. Many municipalities have steep slope regulations. The model flood plain management and geologic hazard regulations include some ideas that may be helpful to planning commissioners and governing body members in reviewing, and possibly strengthening, their existing regulations. In contrast, few municipalities in Allegheny County currently have zoning regulations for the avoidance of subsidence or landslides or for the protection of wetlands. Municipalities with a history of subsidence or landslides should give serious consideration to adopting the model "Geologic Hazard" regulations in the second part of this Chapter. Advice and assistance on wetland protection is available from the Pennsylvania Department of Environmental Resources. (See DER's report, Wetlands Protection: A Handbook for Local Officials, (Environmental Planning Information Series Report #7, May 1990).) a. Special Districts (1) Description. Traditional zoning districts are designed to provide land and regulations which are tailored to general categories of land uses, such as residential, commercial or industrial uses. Special zoning districts, however, go beyond traditional zoning and further unique goals or protect unique resources in a community by establishing specific regulations tailored to the specific character and needs of a particular area. See, e.g., Babcock & Larsen, Special Districts: The Ultimate In Neighborhood Zoning (Cambridge, MA: Lincoln Institute of Land Policy, 1990). Special zoning districts should be based on established goals and policies of the community. For example, a municipality with significant river frontage may have a goal of increasing public access to and recreational use of the river. To implement this goal, the municipality might establish a special riverfront zoning district to implement unique goals for this area. The types of zoning districts that may be established are limited only by the vision and values of the municipality. Special districts are mapped as a base zoning district just like any residential, commercial or industrial zoning district. Base zoning districts are appropriate when the special area is easily identified (such as a central business district or historic district). Another newer type of special zoning district that is most often adopted in suburban communities is a "scenic corridor" district, designed to regulate the traffic and aesthetic impacts of shopping centers, fast-food restaurants and automobile-related uses. This type of district is discussed in greater depth in Chapter IV ("Community Appearance"). (2) Use of Technique in Other Locations. Special districts are most commonly established to protect natural or historical resources; however, special districts have been blossoming throughout this country, notably in New York City and San Francisco. In these cities, special districts have been successfully established to protect the values and cultural heritage of specific areas, such as New York City's Theater District and Garment District, or San Francisco's neighborhood commercial districts. (3) Use of Technique in Allegheny County. Quite a few municipalities within Allegheny County currently have some type of special district. Most of the existing special districts relate to conservation or recreation purposes, or to special institutional uses. However, there are other special or unique areas, such as riverfront areas and strip commercial areas, that could be treated through specially-tailored zoning regulations. The use of special districts is most effective (and politically accepted) if used for truly unique areas. Special districts should be selected with care, based on studies of why the protected area is special. Care should be used in adopting special districts to make sure that their use does not proliferate into something that could be challenged as spot zoning. b. Overlay Districts (1) Description. Overlay zones form a second layer of zoning regulations that are superimposed over underlying residential, commercial or industrial zoning. Whereas the boundaries of traditional zoning districts are mapped on a zoning map, the boundaries of overlay districts are tied to the resource or special interest to be addressed. For example, a house that is proposed to be built on land that is zoned for residential development, and which is also located within a floodplain, may be subject not only to the traditional yard and setback regulations for residential uses, but also to an additional layer of floodproofing standards and other regulations applicable to development within floodplains. Overlay zones require preliminary study or planning to establish goals, policies and justifications for treating these zones differently than other zones. Study may also be needed to identify and map these districts, although it may be possible to merely refer to the natural resource as identified on some existing inventory or map, such as the FEMA flood insurance maps. (2) Use of Technique in Other Locations. Overlay zones have been widely used in many states. Two interesting examples are described below. Mississippi River Corridor Critical Area Overlay District. The City of Cottage Grove, Minnesota, has created a Mississippi River Corridor Critical Area Overlay District to protect the river's transportation, ecological and recreational benefits to the area. The district provides special standards for sewage disposal, subdivision of property and bulk requirements, as well as natural resource management requirements, all of which are more stringent than the regulations for the underlying zoning districts. (See Blackwell, Robert J. "Overlay Zoning, Performance Standards and Environmental Protection After Nollan" Chapter 18 of the 1990 Zoning and Planning Law Handbook, by Mark S. Dennison, ed. (New York, New York: Clark Boardman Company, Ltd., 1990).) Virginia Beach's Agricultural Lands Overlay District. In 1985, the City of Virginia Beach, Virginia, established comprehensive plan policies to preserve the agricultural economy in the City's rural fringes south of the City's "Green Line" or urban services boundary. Growth and development in these agricultural areas was envisioned to remain at a level that could be adequately served by a rural road network, individual wells, septic tanks and limited police and fire protection. However, the City's zoning regulations did nothing to stop the steady conversion of agricultural land to one acre residential lots served by individual wells and septic systems. The Agricultural Lands Overlay District was adopted in 1989 as an interim measure to control further land conversions until more permanent approaches, such as possible use of transfer of development rights (TDR's) could be added in the City's revised comprehensive plan. The interim overlay district essentially increased the minimum lot size (from one acre to 20 acres) in agricultural zones south of the "Green Line." Other uses could be approved by the City Council as special exceptions provided that adequate rural services are available to meet the demands of the development, the development is compatible with surrounding agricultural uses, storm water retention facilities are provided, no paved roads will be constructed, and individual wells will not depress the aquifer from which water will be drawn. (3) Use of Technique in Allegheny County. Natural resources in Allegheny County can and should be protected through overlay districts. Some municipalities are already using overlay districts in flood plains and watersheds. Overlay zoning districts could also be used to protect other types of resources and prevent other types of natural hazards. The second part of this Chapter includes model overlay district regulations for steep slopes, landslide-prone areas, and subsidence areas ("geologic hazard overlay district"). Overlay district approaches are also recommended as a technique for providing recreational opportunities (see "riverfront overlay district" in Chapter III) and improving community appearance (see "scenic corridor overlay district" and "scenic view overlay district" in Chapter IV). c. Tree Protection Standards (1) Description. Significant trees and vegetation may be preserved where appropriate through identification and "mitigation" requirements. When a developer proposes to disturb or destroy natural resources on a particular site, the developer may be required to mitigate the damage and replant or replace the resource. Replacement may not be an appropriate response in some cases. For example, it may not be possible to replace a one-hundred-year old tree. On the other hand, replacement of common ground cover may be an appropriate mitigation measure. (2) Use of Technique in Other Locations. Tampa, Florida's site clearing regulations are an example of a prevalent natural resource protection technique. Tampa's regulations are intended to protect certain trees, the natural landscape and wetlands during any site clearing activities within the City. With certain specified exceptions (commercial tree operations, agriculture, single-family and two-family lots, and sites which are certified as containing no protected trees or wetlands), a special site clearing permit is required from the City's Parks Department as a prerequisite to any site clearing or building permit issuance to ensure that the activity does not harm any protected tree, drainage, soils or wetlands on a parcel. (3) Use of Technique in Allegheny County. Many municipalities in Allegheny County currently have some type of site clearing approval, usually in the form of a grading permit. Existing site clearing standards should be strengthened to require the protection of mature trees, rare species, wildlife habitats, or other unique natural features that are found to exist on the site. d. Environmental Assessments or Site Capacity Analysis (1) Description of Technique. Environmental impact assessments or site capacity analyses conducted by development applicants provide more detailed information in regard to a particular parcel of land than is generally included in community-wide natural resources inventories. After resources are identified, the second part of an environmental assessment examines alternatives to minimize the destruction or degradation of resources and, if necessary, "mitigate" or replace resources if design alternatives are not feasible or practical. Environmental impact statements are required for certain types of federal permits (e.g., for dredging or filling in of wetlands) so that many developers are familiar with these types of studies. Developers familiar with the "curative zoning amendment" process are also familiar with these kind of studies because of similar requirements for that process. The MPC requires the governing body of a municipality to consider the impact of a curative zoning amendment on a site's "soils, slopes, woodlands, wetlands, flood plains, natural resources and natural features" and "the degree to which these are protected or destroyed, the tolerance of the resources to development and any adverse environmental impacts." (MPC S 609.1(c)(4)). Site capacity analysis evaluates the development potential for a particular parcel of land on the basis of the specific characteristics of the parcel. The site capacity analysis technique requires the developer to subtract out all protected areas on a site before calculating the permitted density. The site capacity calculation subtracts all portions of a "base site area" that are inappropriate for development. The remaining buildable portion of a site is then multiplied by a maximum density factor (in the case of residential uses) or by a floor area ratio or impervious surface ratio (in the case of nonresidential uses) to establish allowable amounts of development. (2) Use of Technique in Other Locations. The Lake County, Illinois, Zoning Ordinance contains worksheets for the use of developers in calculating site capacity. The "base site area" is essentially the gross site area as determined by on-site survey, less any land that is not available for building purposes (land within rights-of-way, land which is inaccessible from the main parcel, and open space (land reserved for resource protection or recreation reasons)). In the case of mixed use developments, the base site area is calculated separately for the residential and non-residential components. The base site area is calculated as follows: BASE SITE AREA = Gross Site Area (according to on-site survey) minus: Unbuildable Land (e.g., roads and rights-of-way) minus: Inaccessible Land (cut off by railroad lines, rivers, etc.) minus: Previously Preserved Land (e.g., recreation land in a previously approved subdivision) 1 The next step in calculating site capacity is to identify all the areas of the site that are to be reserved as open space for resource protection or recreation reasons. "Resource protection land" is calculated by assigning certain protection levels or open space ratios to various resources or features. RESOURCE PROTECTION LAND = OPEN SPACE RATIO X ACRES OF RESOURCE (for type of resource) Some sample open space ratios from the Lake County Zoning Ordinance are: Beaches 1.00 X Flood Plains 1.00 X Dunes 0.98 X Wetlands 1.00 X Bluffs 1.00 X Steep Slopes: 12-15% Slope 0.60 15-30% Slope 0.70 (0.85 in areas with unstable soils) 30% and above 0.85 (0.95 in areas with unstable soils) 2 Recreational land is another type of open space that is often required to be excluded under a site capacity analysis. The Lake County Zoning Ordinance imposes recreational land requirements for subdivisions with lots of two acres or less. Recreation land must be calculated for all other residential land uses based on the following formula: RECREATIONAL LAND (for Residential Uses Only) = Base Site Area minus: Resource Protection Land (see formula on preceding page) times: Recreation Multiplier (for appropriate zoning district) 3 Having calculated resource protection lands and recreation lands, the next step in the site capacity analysis is to determine what portion of the site must be reserved as open space. The Lake County Zoning Ordinance defines open space as: OPEN SPACE = the greater of: (1) Resource Protection Land + Recreation Land, or (2) Base Site Area X Open Space Ratio (for applicable zoning district) 4 The Net Buildable Site Area is the Base Site Area minus required Open Space. The Net Buildable Site Area is the area used to calculate the maximum number of dwelling units or the maximum non-residential floor area, using the appropriate density factor and maximum floor area (or impervious surface ratio) for the zoning district. Allowable development is reduced based on subtracting open space from gross site. Clustering, on the other hand, achieves resource protection goals oftentimes without a reduction in density or intensity. (3) Use of Technique in Allegheny County. Several municipalities in Allegheny County currently require some type of natural resources information or environmental impact assessment. Fox Chapel, in the northern part of the County, has an extensive natural features assessment process in its Health and Safety Code that requires the Borough Council and the Borough's Environmental Advisory Council to determine the potential environmental impacts associated with a proposed environmental disturbance and to describe how the impacts should be mitigated. In order to determine whether a development proposal produces unacceptable impacts, however, a municipality that takes this approach must first adopt standards that clearly establish what level of impact is acceptable, or conversely, what level of impact is unacceptable. Findlay Township and Marshall Township have both enacted zoning ordinances that require site capacity analysis similar to that described above. e. Clustered Development (1) Description. Conventional zoning and subdivision ordinances provide developers with few alternatives to simple suburban development patterns. Cluster development, in its simplest form, is an old idea that is worth reviving. Clustering involves variations in lot size without an increase in the amount of development. Clustering can be successfully tailored to provide for compact development, flexibility in site planning, preservation of open space and sensitive natural resources, and buffering, screening and landscaping. Frequently clustering is allowed only in special zoning districts, or planned development districts. However, in order to make better use of the technique and make it attractive and easy to use, municipalities may want to consider allowing clustering in all or most districts. The model cluster development regulations at the end of this Chapter show how this approach can be used. One of the chief virtues of clustering is that it allows for the protection of sensitive natural areas without compromising a property owner's density or intensity expectations. The only requirement in most cases is that the building layouts have to be rearranged to avoid the sensitive areas. A reduction in density is only necessary in extreme cases where sensitive resources pervade a site. In order to fit the same number of units on only half a development site, for example, adjustments in the types of dwelling units, minimum lot size and yards will be necessary. The model regulations at the end of this Chapter recommend that a developer using the cluster option be allowed to build any type of attached or detached dwelling unit, regardless of whether the unit types are otherwise permitted. The model regulations would also allow development on lots smaller in size, with smaller setbacks than the minimum required in a particular zoning district. The only exception would be in a "transition area" just inside the perimeter of the site, where development would be required to come fairly close to the normal lot size and yard standards. (2) Use of Technique in Other Locations. Randall Arendt is the principal author of a design manual for the future development of the Connecticut River Valley which promotes cluster layouts as a more attractive, cheaper, and environmentally sound form of development than traditional "checkerboard" subdivisions. Echo Hill located in Amherst, Massachusetts, is Arendt's favorite example of cluster development at its best. Built in the early 1960's, it is characterized by narrow setbacks, narrow roads (roughly 18 feet wide), organized around a commons or green. In an article appearing in the September 1990 issue of the American Planning Association's Planning Magazine, Echo Hill and other cluster plans are compared with traditional subdivisions. CONVENTIONAL SINGLE FAMILY DEVELOPMENT vs. CLUSTERED DEVELOPMENT (3) Use of Technique in Allegheny County. The zoning enabling legislation in a few states specifically addresses cluster zoning (Illinois, Indiana, Ohio and New York, for example). Even without express authority, courts have upheld cluster ordinances based on general zoning enabling authority, provided that adequate criteria and standards are included. The Municipalities Planning Code does not expressly authorize cluster development; however it does authorize "provisions to encourage innovation and to promote flexibility, economy and ingenuity in development." (MPC S 603(c)(5).) In addition, the purposes of planned residential developments include the provision for innovations in residential and non-residential development by conservation and more efficient use of open space ancillary to dwellings and use. (MPC S 701.) Cluster development is an ideal way to advance both purposes. The PRD legislation contemplates the use of clustering and density bonuses to secure common open space by allowing variation of the normal density or intensity requirements depending on the location and amount of open space that is proposed. (MPC S 705(d)(1).) One municipality in the North Hills target area (Marshall Township) has adopted extensive cluster provisions in its zoning ordinance, including density bonuses. The lot area of single family detached units may be reduced from three acres to one acre in the Countryside District, from 40,000 square feet to 30,000 square feet in the Estate District, and from 20,000 square feet to 14,000 square feet in the Suburban Residential District. f. Industrial Performance Standards (1) Description. Standards "to control noise, odor, smoke, toxic or noxious matter, vibration, fire, and explosive hazards, and glare or heat generated by or inherent in uses of land or buildings," are found in most zoning ordinances. (See Anderson, R., American Law of Zoning (2d ed 1977, p. 67).) These standards essentially codify the common law of nuisance. Many older zoning ordinances incorporate very general language prohibiting these nuisances. Newer ordinances include a longer, more specific list of proscribed hazards, including hazardous waste, toxic substances, stormwater runoff, erosion and sedimentation. Newer ordinances are also more likely to defer to minimum federal or state environmental standards rather than requiring more stringent precautionary measures. (2) Use of Technique in Other Locations. Almost every zoning ordinance written since the early nuisance lawsuits of the 1920's and 1930's includes general industrial performance standards relating to odor, smoke, vibrations, etc. Lake County, Illinois. The Lake County Zoning Ordinance contains industrial performance standards. The industrial performance standards apply to permitted uses in industrial zones and office and research zones, as a condition of building permit issuance. The County may require the industry to install measuring or recording instruments to demonstrate compliance with the maximum permitted levels of noise (measured in decibels), vibration (measured in inches of displacement), smoke and particulate matter (measured in particulate matter emission in pounds per hour per acre), odors (measured in minutes of emission per day), radiation (according to Atomic Energy Commission regulations), fire and explosive hazards (according to state standards), glare and heat (visible emissions beyond the boundary of the lot), and electromagnetic interference (according to Federal Communications Commission regulations). (3) Use of Technique in Allegheny County. Almost all of the zoning ordinances that were reviewed as part of the initial investigation of existing regulations in Allegheny County contained some form of industrial performance standards. In many of these ordinances, the performance standards applied only to conditional uses or were very general. Existing performance standards could be converted to more specific and enforceable standards. 3. Subdivision and Land Development Regulations Subdivision ordinances have become broader and more detailed over the past two decades. In addition to regulating basic things like the location of future lot lines, streets and utility easements, most modern land development regulations and subdivision ordinances now also regulate the impacts of earthmoving activities on natural rates of stormwater runoff, erosion and sedimentation. Statutes requiring municipalities to adopt flood plain, stormwater or erosion control regulations most often result in the adoption of separate ordinances dealing with the particular subject. However, the purpose of these regulations is most effectively carried out if the environmental factors are integrated with other land development standards and considered early on. Environmental standards should be considered when preliminary plats and land development plans are being formulated, rather than after the applicant has already invested significant time and money in the project. Thus, the model regulations included in the second part of this Chapter suggest that erosion control, storm water management and grading requirements be folded into a municipality's subdivision and land development ordinance. Part 2. MODEL ENVIRONMENTAL PROTECTION AND HAZARD CONTROL REGULATIONS The model regulations in this part of the Chapter are drafted as potential amendments to a municipality's zoning or subdivision and land development ordinance and reflect the principal but not all of the techniques discussed in Part 1. To the extent that human and financial resources allow, municipalities should back up their regulations with comprehensive plans, studies and inventories. These are especially important in the current legal environment in establishing a municipality's motivations for regulating the use and development of land. The most comprehensive regulations appear first. Site capacity analysis (sometimes called "environmental impact analysis" or "natural features analysis") is simply a "net buildable" approach. Land that is to be reserved for recreation or protected for conservation is subtracted from the gross land area of a site before the maximum density or intensity limits are applied. Clustering development on a site is another broad approach that can be used to advance a variety of environmental protection, hazard prevention and recreational goals. The same is true of restrictive grading regulations. Another broad approach that is covered in the "Flexible Development" procedures in Chapter VI are information requirements. A variety of environmental plans and data could be required as part of a land development application. A municipality that is considering adopting any of these broad regulatory approaches should first review its existing zoning and subdivision regulations to make sure that the topic is not already covered. The remaining model regulations deal with specific types of natural resources (flood plains, hillsides, trees) or hazards (stormwater runoff, erosion and geologic hazards). The specific regulations may be adopted in addition to the more comprehensive regulations, or adopted separately to address a specific concern. Site Capacity Analysis COMMENT: Site capacity analysis requires a developer to identify the resources on a development site and set aside a designated percentage of each type of resource as open space. If protection standards are included in environmental overlay districts and the result is to set aside protected resources, there is no need for separate open space ratios. Instead, the set aside provisions should refer to the overlay district regulations. The following model site capacity regulations were adapted from the Greater Pittsburgh International Airport Impact Area Plan (July 1988), Appendix A. The appropriate categories of protected resources and the appropriate open space ratios assigned to each category should be reviewed carefully and modified, if necessary, by each municipality. As with other types of environmental regulations, background studies, plans and natural resource inventories are important first steps to establish the relationship between the regulations and the public purposes they seek to achieve. The "whereas" clauses of an ordinance adopting these regulations should reference and describe any background studies and plans. The model regulations are suggested as amendments to a municipality's zoning ordinance. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE ZONING ORDINANCE; PROVIDING FOR SITE CAPACITY ANALYSIS; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR DEFINITIONS; PROVIDING FOR RELATIONSHIP OF ZONING DISTRICT STANDARDS; PROVIDING FOR BASE SITE AREA CALCULATION; PROVIDING RESOURCE PROTECTION LAND CALCULATION; PROVIDING RECREATIONAL LAND CALCULATIONS; PROVIDING FOR DETERMINATION OF SITE CAPACITIES; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a [comprehensive plan with an open space and recreation element or an open space, natural resources and recreation plan]; Whereas, the [element or plan] demonstrates a need for open spaces, natural resources, and recreational lands and facilities in [Municipality] in order to serve new growth and development; Whereas, the [element or plan] establishes minimum standards for the protection of open space lands and other natural resources within [Municipality]; and Whereas, the goals, policies and objectives of the [element or plan] provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of a proposed development; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Zoning Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. The site capacity analysis required by this Section is intended to establish the intensity of development in relation to the natural capabilities of the land to sustain disturbance without incurring significant disruption of the sensitive natural resources; and protect persons and property from hazards resulting from the inappropriate development of land containing sensitive, unstable or hazardous natural resources or features. B. Applicability. (1)All applications for approval of land development under this Zoning Ordinance shall include a Base Site Area Calculation in accordance with Subsection E below, the Resource Protection Land Calculations required by Subsection F below, and the Recreational Land Calculations in Subsection G below. (2)The calculations required by the Resource Protection Land Calculation in Subsection F may be waived by the Planning Commission when it determines that no natural resources or natural features are present on a parcel proposed for development. C.Definitions. For the purposes of this Section, the following terms shall have the following meanings: "Base Site Area" means that portion of a parcel as calculated pursuant to Subsection E of this Section. "Gross Density" means the quotient of the total number of dwelling units divided by the base site area of a site, expressed in dwelling units per acre. "Density Factor" means the density on the buildable portion of a site, or the number of dwelling units per net buildable site area. "Diameter at Breast Height (DBH)" means a measurement of the size of a tree equal to the diameter of its trunk measured 4.5 feet above natural grade. "Drainageway" means any area to which runoff from surrounding land flows naturally or is caused to flow from existing land alterations and which conveys such runoff to a watercourse. "Floor Area Ratio" means a measure of building intensity derived as a ratio by dividing the total floor area of a building by the base site area. "Impervious Surface" means any hard-surfaced area that does not readily absorb or retain water, including but not limited to, building roofs, parking and driveway areas, sidewalks and paved recreational facilities. "Impervious Surface Ratio" means a measure of the intensity of land use which is determined by dividing the total area of all impervious surfaces on a site by, in the case of residential uses, base site area, or, in the case of nonresidential uses, by net buildable site area. "Land Development" means the improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving: (1)A group of two or more residential or nonresidential buildings, whether proposed initially or cumulatively; (2)A single nonresidential building on a lot or lots regardless of the number of occupants or tenure; (3)The division or allocation of land or space, whether initially or cumulatively, between or among two or more exiting or prospective occupants by means of, or for the purpose of streets, common areas, leaseholds, condominiums, building groups or other features; or (4)The subdivision of land. (See definition of "subdivision" in Section of the Subdivision and Land Development Ordinance). "Land Development" shall not include: (5)The conversion of an existing single-family detached dwelling or single family semi-detached dwelling into not more than three residential units, unless such units are intended to be a condominium; (6)The addition of an accessory building, including farm buildings, on a lot or lots subordinate to an existing principal building; or (7)The addition or conversion of buildings or rides within the confines of a previously approved amusement park (or "a tract or area used principally as a location for permanent amusement structures or rides"). COMMENT: Subparagraphs (1) - (4) are from the definition of "land development" in S 107 of the MPC. The exemptions listed in subparagraphs (5) - (7), which are optional, are authorized under S 503(1.1) of the MPC. "Landslide-Prone Areas" means any steep slope which is especially susceptible to landslides due to the presence of unstable rock formations or soil types. COMMENT: See model regulations for "Geologic Hazard Overlay District" elsewhere in this Part for other recommended regulations. "Net Buildable Site Area" means the base site area less total open space or minimum open space required for resource protection and recreation under this Section. "Non-Residential Use" means any use except a residential use. "Open Space" means land used for recreation, resource protection, amenity and/or buffers, not including any area of a lot constituting the minimum yards, parking area or any part of an existing or future road or right-of-way. "Open Space Ratio" means the ratio derived by dividing open space by the base site area. COMMENT: The "district open space ratio" is the minimum percentage of open space required in a particular zoning district. If there is no open-space ratio, it can be calculated by subtracting the maximum building coverage percentage plus some reasonable percentage for roads and parking areas. "Recreation Factor" means that portion or percentage of a development site which is required to be reserved or dedicated for park and recreation purposes under Section of the Subdivision and Land Development Regulation. COMMENT: Park and recreation requirements may also be expressed as a certain number of acres per proposed dwelling unit. See, for example, model regulations for "Park and Recreation Facilities" in Chapter III. "Residential Use" means a use of land which provides space for the permanent occupancy of either individuals or families within dwellings, including single-family dwellings, duplexes, townhouses, apartments and [list other dwelling types]. "Site" means a parcel of land for which land development approval is sought pursuant to the Subdivision and Land Development Ordinance. "Steep Slopes" means an area where the inclination (vertical distance over horizontal distance) of the land's surface is 16-25% for moderately steep slopes, 26-40% for steep slopes and over 40% for very steep slopes. COMMENT: See model regulations for Geologic Hazard Overlay District for other regulations pertaining to steep slopes. "Woodland" means a plant community composed predominantly of healthy trees and other woody vegetation, well-stocked and growing more or less closely together. "Woodland, Mature" means a woodland whose total combined canopy covers an area of _____ acre or more, and at least ___ [50?] percent of which is composed of canopies of trees having a diameter at breast height (DBH) of at least twelve (12) inches, or any grove consisting of [8] or more individual trees having a DBH of at least twelve [12] inches whose combined canopies cover at least [50?] percent of the area encompassed by the grove; provided however that no trees kept or grown for commercial purposes shall be considered a mature woodland. "Woodland, Young" means a woodland whose total combined canopy covers an area of ____ [one-half] acre or more, and at least ____ [50?] percent of which is composed of canopies of trees having a diameter at breast height (DBH) of at least three (3) inches; provided however that no trees kept or grown for commercial purposes shall be considered a young woodland. D.Relationship of Zoning District Standards to Site Capacity Analysis. All subdivisions and land developments shall comply with the standards set out in the applicable zoning district regulations in this Zoning Ordinance governing the maximum density or intensity of development. The site capacity calculations in this Section provide the mechanism for subtracting from the base site area all portions of a site that are inappropriate for development, prior to applying the appropriate density or intensity limit. E.Base Site Area Calculation. The first step in the determination of the site capacity is to establish the base site area. If site capacity analysis is required, the following calculations shall be submitted. (1)Gross site area as determined by on-site survey or legal records. _________ acres (2)Subtract land constituting roads and land within ultimate rights-of-way of existing roads, rights-of-way of utilities, and easements of access. _________ acres (3)Subtract land which is not contiguous: a.a separate parcel which does not abut, adjoin, or share common boundaries with the rest of the development; _________ acres b.land which is cut off from the main parcel by a road, railroad, existing land uses, or major stream so that common use is hindered or the land is unavailable for building purposes. _________ acres (4)Subtract land that, in a previously approved subdivision encompassing the same land as part or all of the subject parcel, was reserved for resource reasons (e.g., flooding or recreation). _________ acres (5)Subtract land used or proposed for residential uses, whenever both nonresidential and residential uses are proposed. (In the case of the site capacity calculation for a proposed residential use, subtract the land proposed for nonresidential use.) _________ acres (6)Subtract estimated land required for bufferyard areas. (Do not subtract bufferyard areas where they coincide with resource protection lands.) _________ acres (7)Equals base site area. _________ acres F.Resource Protection Land Calculation. (1)Specific natural resources that are sensitive to development, such as steep slopes, floodplains, and woodlands, are protected under this Section and other applicable provisions of the Zoning Ordinance. All land area consisting of the natural resources or natural features listed in the following table shall be measured by the developer. The resource protection land shall be calculated in the following manner: a.Calculate the total area of each natural resource. b.Multiply the total area of each resource by the open space ratio for that resource to determine the amount of resource protection land or area required to be kept in open space in order to protect the resource or feature. c.On that portion of the site where two or more resources overlap, only that natural resource which has the highest open space ratio shall be calculated. d.The sum total of all resource protection land on the site equals the total resource protection land. COMMENT: Some municipalities may be unfamiliar with open space ratios, impervious surface ratios and land use intensity classifications. For a good discussion of these concepts the reader may wish to consult Lane Kendig's book Performance Zoning. The following subsection illustrates the types of resources that a municipality may wish to protect and some sample open space ratios. These ratios are examples only and should be carefully reviewed by individual municipalities based on their characteristics and policies. Municipalities should be especially aware of whether the open space ratio assigned to a particular category of resources is consistent with other regulations that apply to that resource. For example, the model regulations included in this Chapter for floodplains (see "Flood Plain Overlay District") would prohibit any structures below the 100-year flood elevation. This is consistent with the 100% open space ratio assigned to floodplains in the table which follows. Many municipalities in Allegheny County currently allow structures in floodplains. A lower open space ratio would be appropriate in these municipalities if structures are to continue to be allowed in floodplains. Development regulations for other types of natural resources should also be reviewed for consistency with the open space ratios in the table which follows. (2) Resource Protection Land/Open Space Natural Resource Open Space Acres of Land Acres in Feature (All Districts) Ratio in Resource x Open Space Ratio Drainageways .50 Floodplains 1.00 Mature Woodlands .70 Woodlands .60 Young Woodlands .40 Moderately Steep .60 Slopes (16% - 25%) Steep Slopes .85 (25% - 40%) Very Steep Slopes 1.00 (>40%) Landslide-Prone 1.00 Areas Wetlands 1.00 TOTAL LAND IN RESOURCE TOTAL RESOURCE PROTECTION LAND G.Recreational Land Calculations (Residential Uses Only). Total recreational land required for residential uses is calculated as follows: Take BASE SITE AREA _____ Subtract TOTAL ACRES OF LAND IN RESOURCE PROTECTION -_____ EQUALS TOTAL UNRESTRICTED LAND =_____ Multiply by RECREATION FACTOR x_____ EQUALS TOTAL RECREATIONAL LAND REQUIRED =_____ SubtractAny resource protection land that will be improved for recreation. EQUALS TOTAL RECREATION LAND REMAINING TO BE PROVIDED =_____ H.Determination of Site Capacity (Residential Land Uses). Individual site capacity is determined by calculating the net buildable site area. For residential developments, the number of dwelling units permitted is determined by multiplying the density factor by the net buildable site area. The calculations are as follows: Take TOTAL RESOURCE PROTECTION LAND _____ Add TOTAL RECREATION LAND REMAINING TO BE PROVIDED +_____ EQUALS TOTAL OPEN SPACE =_____ Take BASE SITE AREA _____ Multiply by DISTRICT OPEN SPACE RATIO x_____ EQUALS MINIMUM REQUIRED OPEN SPACE =_____ Take BASE SITE AREA _____ Subtract TOTAL OPEN SPACE OR MINIMUM REQUIRED OPEN SPACE, whichever is greater -_____ EQUALS NET BUILDABLE SITE AREA =_____ Multiply by DISTRICT MAXIMUM DENSITY FACTOR x_____ EQUALS NUMBER OF DWELLING UNITS (Do not round off; use lowest whole number) =_____ I.Determination of Site Capacity (Nonresidential Uses). In order to determine the site capacity of a particular site, both maximum impervious surface area and maximum floor area must be calculated as follows: Take BASE SITE AREA _____ Subtract RESOURCE PROTECTION LAND -_____ EQUALS BUILDABLE LAND =_____ Divide by BASE SITE AREA -_____ EQUALS CALCULATED IMPERVIOUS RATIO =_____ Take IMPERVIOUS SURFACE RATIO (From land use intensity class of proposed use or district maximum, whichever is less) _____ If the IMPERVIOUS SURFACE RATIO is equal to or less than the CALCULATED IMPERVIOUS SURFACE RATIO, then: Take BASE SITE AREA _____ Multiply by IMPERVIOUS SURFACE RATIO x_____ EQUALS PERMITTED IMPERVIOUS AREA =_____ Take BASE SITE AREA ______ Multiply by FAR (From land use intensity class of proposed use or district maximum, whichever is less) x_____ EQUALS PERMITTED FLOOR AREA =_____ If the IMPERVIOUS SURFACE RATIO is more than the CALCULATED IMPERVIOUS RATIO, then: Take BASE SITE AREA ______ Multiply by CALCULATED IMPERVIOUS RATIO x_____ EQUALS PERMITTED IMPERVIOUS AREA =_____ Take CALCULATED IMPERVIOUS RATIO ______ Divide by IMPERVIOUS SURFACE RATIO -_____ EQUALS REDUCTION FACTOR =_____ Take FLOOR AREA RATIO (or maximum floor area factor, whichever is more restrictive) ______ Multiply by REDUCTION FACTOR x_____ EQUALS REQUIRED FLOOR AREA FACTOR =_____ Multiply by BASE SITE AREA x_____ EQUALS PERMITTED FLOOR AREA =_____ Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Cluster Development Option COMMENT: Clustering development on portions of a site that are most suitable for development, regardless of minimum yard requirements and lot sizes, may be desirable in some zoning districts. These model regulations are suggested as amendments to a municipality's zoning ordinance. Municipal officials are encouraged to read the background materials on clustering in the first part of this Chapter. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE ZONING ORDINANCE; PROVIDING FOR CLUSTER DEVELOPMENT OPTIONS; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR CLUSTER DEVELOPMENT OPTION; PROVIDING STANDARDS; PROVIDING FOR PRESERVATION OF PROTECTED NATURAL RESOURCES; PROVIDING FOR COMPLIANCE WITH SUBDIVISION AND LAND DEVELOPMENT STANDARDS; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the plan demonstrates a need for open spaces, natural resources, and recreational lands and facilities in [Municipality] in order to serve new growth and development; and Whereas, implementation of the goals, policies and objectives of the comprehensive plan requires that provision be made to allow for flexibility in the application of the zoning ordinance in order to ensure the preservation of open space, natural resources and recreational lands; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Zoning Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This Section is intended to encourage flexible site designs, protect environmentally sensitive areas of a development site and encourage the preservation of sensitive areas as public or private open space. B.Applicability. The cluster development option is available by right in any zoning district. COMMENT: Cluster provisions are most commonly applied to residential zoning districts or PRDs but should be encouraged in other zoning districts as well in order to protect natural resources, promote flexible designs, and provide recreational opportunities. C.Cluster Development Option. Subject to the requirements of subsection D below, the cluster development option allows for residential development on lots smaller in size and/or with smaller yards than the minimum required by the zoning district in which the property is located, and allows for any type of attached or detached dwelling units, regardless of whether such unit types are otherwise permitted. COMMENT: Allowing other types of dwelling units could be optional. D.Standards. Development using the cluster development option shall meet each and every one of the following standards: (1)The developer must be the legal owner of the entire parcel proposed for development. (2)The developer shall identify all natural resources on a parcel proposed for cluster development. COMMENT: If a municipality does not currently have a map or inventory of natural resources, this section should require an individual site capacity analysis of the site. See Subsection F(2) in the model site capacity regulations above for examples of resources that might be protected. (3)The maximum number of dwelling units developed on the parcel proposed for development shall not exceed the number of dwelling units otherwise permitted for the zoning district in which the parcel is located. (4)The land area located one hundred (100) feet or closer from the boundary of any cluster development shall form a transition area within which no lot may be less than ninety percent (90%) of the minimum lot area that would otherwise be required under the ordinary zoning district regulations. COMMENT: The appropriateness of this buffer would depend upon the size of the cluster development. (5)The land area devoted to paved roads and driveways shall not exceed ten percent (10%) of the total area of the parcel proposed for development. COMMENT: This standard also depends on character and size of the development. (6)No dwelling unit or other structure shall exceed the maximum height allowed in the applicable zoning district. E. Preservation of Protected Natural Resources as Open Space. The portion of the property which is identified as a protected natural resource shall be set aside as common open space. The portion of the property to be set aside shall be dedicated as public open space if deemed necessary or appropriate by the [Governing Body] based on public recreation needs documented in the comprehensive plan or other public documents. Alternatively, the [Governing Body] may approve the transfer of the natural resource protection areas of the site to a not-for-profit conservation organization. F.Compliance with Subdivision and Land Development Standards. The use, design, location and maintenance of common open space within a cluster development shall be in accordance with the standards contained in Section of the Subdivision and Land Development Ordinance. COMMENT: See model regulations for park and recreation areas in the "Recreational Opportunities" Chapter. Standards for common open space in PRDs are also included in the model "PRD" regulations in Chapter VI. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Grading Standards COMMENT: It is not an uncommon sight in Allegheny County to see a landowner clearing and grading hillsides on the speculation that a developer will pay for a ready-to-build site. This practice is unnecessarily devastating to the environment. Without knowing what will be built, a speculator typically clears a large, flat development "pad" that is big enough for a variety of possible uses. The landowner's mindset is to err on the high side rather than minimize the destruction of trees and hillsides. The model regulations below are suggested amendments to a municipality's subdivision and land development ordinance. They are intended to prohibit speculative grading by requiring a developer to submit a development plan as a condition of grading approval. The regulations are also intended to restrict grading in areas where earth disturbance may create hazards, including areas which are susceptible to landslides, subsidence or flooding Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE [SUBDIVISION AND LAND DEVELOPMENT ORDINANCE]; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR GRADING PLAN; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to protect its natural environment and ensure that its hillsides are not unnecessarily cleared and graded; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Subdivision and Land Development Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This Section is intended to ensure that development does not result in erosion and in flooding during the site preparation and development process, to prevent the creation of hazards, and to protect natural resources. B.Applicability. No earthmoving or grading activities shall occur unless the landowner, or the landowner's agent, has first submitted and obtained approval of a preliminary plat or land development site plan showing the uses and development which are proposed for the site. C.Grading Plan. A grading plan for all development shall be approved according to the following: (1)A grading plan shall be submitted and approved as part of an application for preliminary plat or site plan approval under the Municipal Subdivision and Land Development Ordinance. (2)Grading activities shall be strictly limited to the minimum area necessary to provide for buildings, parking areas and other facilities shown on an approved preliminary plat or site plan. (3)Trees and other natural vegetation shall only be disturbed in the immediate area of proposed construction. The soil within the drip line of trees that are to remain shall be protected during excavation and grading. Any vegetation that is damaged or destroyed as a result of clearing or grading activities shall be replanted within a reasonable time after construction is complete. Plantings shall be indigenous to the area in which the project is located. (4)Grading activities shall not be permitted on any areas of a site which are potentially prone to landslides or subsidence, based on the most current information available from the Allegheny County Planning Department or the Pennsylvania Department of Environmental Resources, unless a registered professional engineer or geotechnical consultant with appropriate professional insurance has certified that the proposed grading will not create an unsafe condition. (5)Grading shall not be allowed below the 100 year flood elevation, as shown on the most current flood insurance rate maps, or within 50 feet of the top-of-bank of any watercourse, without first obtaining the appropriate permit from the Pennsylvania Department of Environmental Resources. COMMENT: If a municipality has enacted zoning regulations such as site capacity analysis or slope protection overlay district provisions, requiring development plan approval before issuing a grading permit will ensure that grading complies with all applicable standards. (6)The methods of grading used shall be designed to avoid increased stormwater runoff and erosion, in conformance with the requirements of Article of the Subdivision and Land Development Ordinance. COMMENT: Stormwater management and erosion control regulations may be in a separate ordinance. If so, they should be integrated in the subdivision and land development ordinance. (7)The [Planning Commission or Governing Body -- whichever is responsible for land development approval] may require appropriate measures to protect adjacent properties from grading activities, including but not limited to, subsurface support structures, retaining walls, safety nets or fences, and warning signs. (8)The angle for graded slopes and fills shall be no greater than the angle which can support vegetative cover or other adequate erosion control devices or structures. Slopes failing to retain or support vegetative stabilization must be either re-graded (e.g., reduce the slope or terrace the embankment) or make use of permanent structural devices to prevent erosion (e.g., a retention wall or man-made stabilization). COMMENTS: A municipality may wish to supplement these regulations with additional technical standards that regulate the method of grading to ensure that the objectives of subsections (7) and (8) will be achieved. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Flood Plain Overlay District COMMENT: These model regulations are primarily intended to address the problem of flash flooding along smaller creeks and stream valleys. They suggest that flood-prone areas (floodways and flood fringe areas) be left essentially as they are now, and that reconstruction or expansion of existing development be prohibited. The minimum flood plain standards that most municipalities now have would allow development in flood-fringe areas with minimal flood-proofing precautions and would also allow uses that are highly susceptible to flood damage, such as mobile homes. These model regulations would prohibit almost all uses in flood-fringe areas, and thus would eliminate the need for detailed flood-proofing standards. In municipalities where there is existing development in flood plain areas, the restrictions on new development in flood prone areas should be enacted as an amendment to the existing flood plain regulations. In such communities the standards for flood-proofing of structures and certain other requirements contained in DCA's guidelines should be retained. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE ZONING ORDINANCE; PROVIDING FOR A FLOOD PLAIN OVERLAY DISTRICT; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING DEFINITIONS; PROVIDING FOR APPLICABILITY; PROVIDING FOR USE RESTRICTIONS; PROVIDING FOR NOTICE; PROVIDING FOR WARNING AND DISCLAIMER; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to ensure that no new development of structural uses occurs within protected flood plain areas and aspires to protect existing development that is located in flood-prone areas; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Zoning Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. The intent of the Flood Plain Overlay District is to: (1)minimize the risk of flood damage, danger to the public safety, risk of damage to property and financial burdens which may be imposed on the community by the continued development of flood-prone areas; (2)encourage existing development in flood-prone areas to utilize appropriate flood-proofing practices in order to prevent or minimize flood damage in the future; and (3)Comply with federal and state flood plain management requirements. COMMENT: The Pennsylvania Department of Community Affairs has issued three publications containing suggested provisions meeting the minimum requirements of Section 60.3(b), Section 60.3(c) and Section 60.3(d) of the National Flood Insurance Program and the Pennsylvania Flood Plain Management Act (1978-166), dated March and June 1988. However, these publications acknowledge that the minimum suggested regulations do not contain everything that is necessary or desirable for good flood plain management. These model regulations suggest a more aggressive approach to reducing the risk of flood damage than the minimum requirements published by the State. B.Definitions. For the purposes of these regulations, the terms below shall have the meanings ascribed to them as follows: "One Hundred (100) Year Flood Elevation" means the highest level of flooding that, on the average, is likely to occur every 100 years; that is, that has a one percent chance of occurring each year, although the flood may occur in any year, and which is identified as Zone A (Area of Special Flood Hazard) on community panel # of the most recent Flood Insurance Rate Map (FIRM) issued by FEMA prepared for [Municipality], effective [date]. "Flood of Record Elevation" means the highest level of flooding that has actually occurred within the past 100 years. C.Applicability. The Flood Plain Overlay District imposes a set of requirements in addition to those of the underlying zoning district within the One Hundred (100) Year Flood Elevation. Land within the Flood Plain Overlay District may be used only under the conditions of this district and the underlying zoning districts. COMMENT: If no flood insurance maps have been prepared for a municipality, the municipality might consider requiring an applicant within fifty (50) feet of the top-of-bank of a watercourse to identify the one hundred year elevation or flood of record elevation, whichever is greater, as well as a floodway area, if possible, based on other sources of flood information. If flood insurance maps have been prepared, the Federal Insurance Administration approval may be necessary to adjust flood plain boundaries shown on these maps. D.Use Restrictions. No new construction or development (including enlargement or replacement of existing structures) shall be permitted below the 100-year flood elevation, or, if the 100-year flood elevation has not been mapped, within any area measured fifty (50) feet landward from the top-of-bank of any watercourse except: (1)Non-structural accessory uses, such as yards, gardens, and parking areas; and (2)Parks, playgrounds and outdoor recreation facilities not requiring structures. COMMENT: The suggested use list above is more restrictive than the minimum requirements of the flood plain law. The flood plain law would allow even vulnerable land uses, such as mobile homes, hospitals, jails, nursing homes, etc., within flood plain areas subject to special development standards. Municipalities should examine the underlying zoning districts carefully to determine which uses should be prohibited, and list these uses above. The famous case of First English Evangelical Lutheran Church v. County of Los Angeles, 482 U.S. 304, 107 S.Ct. 2378 (1987), may have scared some municipalities into believing that use restrictions in flood plains constitute an illegal "taking" for which a municipality must pay compensation. The Los Angeles ordinance in that case prohibited any buildings or structures within an interim flood protection area. Although the Supreme Court held that it was possible for a municipality to have to pay damages for a regulatory taking, when the case was remanded, no taking was found to occur. The law in this area continues to rely heavily on the facts in a specific case. In general, municipal regulations stand a greater chance of surviving a takings challenge if the reasons for the regulations are well documented. E.Notice to Prospective Purchasers. No subdivision plat or land development plan shall be recorded for any parcel in the Flood Plain Overlay District unless the landowner records the following notice with their deed: "NOTICE TO PROSPECTIVE PURCHASERS": All or part of this parcel has been classified as a flood-prone area, subject to special Flood Plain Overlay District requirements set forth in the Zoning Ordinance. Permitted land uses in flood-prone areas are strictly limited to non-structural uses. F.Warning and Disclaimer of Liability. The degree of flood protection sought by the provisions of these overlay district regulations is considered reasonable for regulatory purposes and is based on acceptable engineering methods. Larger floods may occur. Flood heights may be increased by man-made or natural causes, such as ice jams and bridge openings restricted by debris. These regulations do not imply that areas outside any identified floodplain overlay district, or that uses permitted within such area will be free from flooding or flood damage. These regulations shall not create liability on the part of the [Municipality] or any officer or employee thereof for any flood damage that result from reliance on this Zoning Ordinance or any decision lawfully made hereunder. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Stormwater Management Development Standards COMMENT: Stormwater management regulations are intended to serve as a companion to flood plain management regulations. Whereas flood plain management is intended to guard against damage from flooding through limiting development in flood plain areas and by flood proofing requirements, etc., stormwater management attempts to check the sources of the flood waters at the source by requiring measures to prevent increases in post-development rates of runoff. Under the Pennsylvania Storm Water Management Act, counties are responsible for preparing and adopting stormwater management plans on a watershed basis. Where such plans have been prepared and adopted, municipalities are required to enact ordinances which incorporate the standards and requirements of the adopted watershed plan. Watershed plans and model implementing regulations have been prepared for a number of watersheds in Allegheny County. Municipalities within these watersheds have either amended or are in the process of amending their zoning and subdivision and land development ordinances to incorporate the specific regulations which have been prepared as a part of each watershed plan. The model regulations below are intended to apply to proposed developments that are not within watersheds for which plans and implementing regulations have been prepared and adopted. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE [SUBDIVISION AND LAND DEVELOPMENT ORDINANCE]; PROVIDING FOR STORMWATER MANAGEMENT DEVELOPMENT STANDARDS; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR GENERAL STANDARDS; PROVIDING FOR SPECIFIC STANDARDS; PROVIDING FOR OWNERSHIP AND MAINTENANCE; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to prevent increases in rates of stormwater runoff and effectively manage the stormwater runoff that does result from new development; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows: Section 1. The Subdivision and Land Development Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This section is intended to provide for the management of stormwater runoff resulting from land alteration and disturbance activities to ensure that new development does not result in greater erosion and does not exacerbate existing flood conditions or create additional flooding problems; and: (1)To utilize and preserve existing natural drainage systems; (2)To preserve the flood-carrying capacity of streams and maintain and improve the quality of streams; (3)To encourage natural infiltration of rainfall to preserve groundwater supplies and stream flows; and (4)To provide for adequate maintenance of all stormwater management structures in the municipality. B.Applicability. The Stormwater Management Development Standards shall apply to all proposed subdivisions and land developments within [Municipality] that are not within a watershed with an adopted plan and regulations which are in effect. (1)No final subdivision or land development plan shall be approved, no permit authorizing construction issued, or any earthmoving activity initiated until a final stormwater management plan for the development site has been approved. (2)A small development which will result in the creation of 5,000 or fewer square feet of impervious surface shall be exempt from the detailed stormwater management plan submission requirements of this section, but shall be required to comply with the general and specific standards. An application for approval of a small development shall include sufficient information to enable the municipal engineer to determine that compliance with the stormwater management standards of this section will be achieved. C.General Standards. All stormwater control measures shall comply with the following performance standards: (1)Any landowner and any person engaged in the alteration or development of land which may affect stormwater runoff characteristics shall implement such measures as are reasonably necessary to prevent injury to health, safety, or other property. Such measures shall include such actions as are required: a.To assure that the maximum rate of stormwater runoff is no greater after development than prior to development activities; or b.To manage the quantity, velocity and direction of resulting stormwater runoff in a manner which otherwise adequately protects health and property from possible injury. (2)The stormwater management plan for the development site must consider all the stormwater runoff flowing over the site. (3)No discharge of toxic materials into any stormwater management system shall be permitted. D.Specific Standards. Stormwater management facilities shall be designed to meet the following specific standards: (1)Design Storms. Stormwater management facilities on all development sites shall control the peak stormwater discharge for the 2-, 10-, 25- and 100-year storm frequencies. The SCS 24-hour, Type II Rainfall Distribution models shall be used for analyzing stormwater runoff for both pre- and post-development conditions. The 24-hour total rainfall for these storm frequencies in the watershed are: Rainfall Depth Storm Frequency (in inches) 2-year 2.50 10-year 3.61 25-year 4.31 100-year 5.71 COMMENT: These rainfall depths were taken from the Turtle Creek Watershed Stormwater Management Plan and may need to be adjusted in other areas. For additional information or data on other storm return periods, consult the "Rainfall Duration Frequency Tables for Pennsylvania," produced by DER, Office of Resource Management, Bureau of Dams and Waterways Management, Division of Stormwater Management, Harrisburg, February, 1983. (2)Release Rate Percentage. The release rate percentage defines the percentage of the pre-development peak rate of runoff that can be discharged from an outfall on the site after the development. COMMENT: In municipalities that do not have an adopted watershed plan, a 100% release rate should be applied to all development. In other words, the pre- and post-development hydrographs for the 2-, 10-, 25- and 100-year storms should match. (3)Procedure for Using Release Rate Percentages: The steps that must be followed to utilize the release rate percentage for a particular development site are: a.Compute the pre- and post-development runoff hydrographs for each stormware outfall for the site, using the soil cover complex method (SCS TR-55), for the 2-, 10-, 25- and 100-year design storms, applying no on-site detention for stormwater management but including any techniques to minimize impervious surfaces and/or increase the time of concentration for stormwater runoff flowing over the development site. If the post-development peak runoff rate is less than or equal to the pre-development peak runoff rate, then additional stormwater control shall not be required at that outfall. If the post-development peak runoff rate is greater than the pre-development value, additional controls will be required. b.Multiply the peak discharge percentage by the pre-development rate of runoff from the development site to determine the maximum allowable peak discharge from any detention facility for the 2-, 10-, 25- and 100-year storm events. (4)Staged Development. If the development is to be constructed in stages, the applicant must demonstrate that stormwater facilities will be installed to manage stormwater runoff safely during each stage of development. E. Ownership and Maintenance of Facilities. (1)Unless the [Governing Body] expressly agrees to private ownership of stormwater management facilities, these facilities shall be dedicated to [Municipality] or to a special management district authorized to own and maintain stormwater management facilities. (2)If stormwater management facilities will be privately owned, a maintenance agreement shall be executed prior to final approval of any subdivision or land development plan. (3)[Municipality] expressly reserves the right to inspect all public and private stormwater management facilities. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Erosion and Sediment Control COMMENT: The erosion control measures recommended in DER's 1974 and 1990 erosion control manuals are minimum standards only and may not contain the most up-to-date thinking on erosion control methods. Municipalities should, therefore, consider their review of erosion control plans to be the first and strongest defense against erosion and sedimentation problems. Although the state only requires erosion control permits for projects exceeding 25 acres, municipalities are encouraged to adopt these stricter regulatory standards and require erosion control plans for land developments of five acres or more. These regulations should not be adopted as a separate erosion control ordinance, but are recommended as amendments to a municipality's subdivision and land development ordinance. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE [SUBDIVISION AND LAND DEVELOPMENT ORDINANCE]; PROVIDING FOR EROSION AND SEDIMENTATION CONTROL; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to prevent damage from erosion and sedimentation that could result from new development; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Subdivision and Land Development Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This section is intended to ensure that development does not result in erosion and in flooding during the site preparation and development process. B.Applicability. All persons engaging in land development activities, including any earthmoving activity, shall minimize both on- and off-site erosion and sedimentation to the greatest extent practicable to achieve the following basic control objectives: (1)Protect Critical Areas. On-site areas that are subject to severe erosion, and off-site areas that are particularly vulnerable to damage from erosion and/or sedimentation are to be identified and appropriate mitigative measures are to be used to protect those areas. (2)Limit the Area Exposed. All earthmoving activities are to be planned and conducted in such a way as to minimize the area of land exposed to the greatest extent possible. (3)Limit the Time of Exposure. All earthmoving activities are to be planned and conducted to limit exposure of the disturbed area for the shortest feasible time. (4)Limit the Erosive Potential in the Area Exposed. All earthmoving activity is to be planned and conducted to minimize the erosive potential in exposed areas to the greatest extent possible. (5)Control Upgrade Surface Water. Surface water runoff originating upgrade of exposed areas is to be controlled to reduce erosion and sediment loss during the period of exposure. COMMENT: Ideally, upgrade runoff should be diverted to drainage ways that do not pass through an exposed area. However, on some projects this is not possible. In such instances, upgrade runoff should still be kept separate from exposed soils by use of plastic slope drains or well stabilized drainage channels. (6)Control Stormwater Runoff. When the increase in the velocity of storm water runoff resulting from earthmoving activity is sufficient to cause accelerated erosion of the receiving watercourse, plans are to include measures to control the velocity at the point of discharge so as to minimize accelerated erosion. (7)Control Sedimentation. All earthmoving activity is to be planned and conducted so as to prevent off-site sedimentation damage. C.Erosion and Sediment Control Measures. An application for final approval of any land development involving 5 acres or more shall include an erosion control plan demonstrating compliance with the erosion control measures recommended in the most recent state erosion control manual, the basic objectives in Subsection A, above, and the following standards: (1)Stabilization. All slopes, channels, ditches or any other disturbed area shall be promptly stabilized after final land disturbing activities have been completed. When it is not possible to permanently stabilize a disturbed area immediately after final land disturbing activity, or where land disturbing activity ceases for more than 20 days, temporary stabilization measures shall be promptly implemented. (2)Design and Performance of Control Measures. Erosion and sediment control measures, structures, and devices shall be planned, designed, and constructed so as to provide protection from accelerated erosion and sedimentation from the calculated maximum peak rates of runoff from the ten year frequency storm. Runoff rates shall be calculated using procedures recommended in Chapter 4 of the 1990 Erosion and Sediment Pollution Control Manual published by the Department of Environmental Resources. COMMENT: Since the vast majority of all sediment delivery to natural waterbodies and watercourses is attributed to large storm events and maintenance on construction projects is typically lax at best, many programs across the nation are requiring the sizing of erosion and sediment control devices to handle the twenty-five (25) year storm event. This provides an adequate safety margin for the larger than normal storm event. (3)Improvement Security. The applicant shall file an improvement security in the form of an escrow account, surety bond, irrevocable letter of credit, or other form satisfactory to the Municipal Solicitor, in an amount deemed sufficient by the Municipal Engineer to cover all costs of protection and stabilization of the site in the event that abandonment, bankruptcy, death, or some other factor prevents stabilization of exposed areas. The security shall remain in force until all planned improvements and stabilization are completed. The security shall be forfeited if more than 60 days have passed since final earthmoving activity and temporary stabilization has not been implemented. The applicant shall provide written notice when final stabilization has been achieved and the Municipal Engineer will inspect the site to verify compliance. Upon a finding of compliance, the Municipal Solicitor shall release the improvement security. COMMENT: Enforcement is the principal problem with erosion and sediment control. Improvement security requirements are powerful motivators for compliance. If a municipality's land development ordinance already contains adequate security provisions, the provision above could be omitted. (4)Maintenance Area. Maintenance of silt traps and other control measures is essential. All erosion and sediment control plans shall provide adequate space to, and around control measures to permit access of earthmoving equipment for maintenance and removal purposes. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Geologic Hazard Overlay District COMMENT: Geologic hazards include steep slopes, landslides and subsidence. These hazards pose a serious problem in some areas of Allegheny County. These model regulations are suggested as an amendment to a municipality's zoning ordinance to establish an extra layer of strict zoning requirements in geologic hazard areas. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE ZONING ORDINANCE; PROVIDING FOR GEOLOGIC HAZARD OVERLAY DISTRICT; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR DEFINITIONS; PROVIDING FOR PERMITTED USES; PROVIDING FOR ON-SITE INVESTIGATION AND REPORTING; PROVIDING FOR OPEN SPACE REQUIREMENTS; PROVIDING FOR WARNING AND DISCLAIMER; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to prevent damage to life and property from landslides, subsidence and other dangers that could result from new development located on or near steep slopes or other hazardous geological areas; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Zoning Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. The Geologic Hazard Overlay District is intended to supplement the requirements of general zoning districts wherever geologic hazards are found in order to prevent loss of health, life or property from landslides, subsidence and other dangers; and regulate uses and development on or near steep slopes or other hazardous geological features. B.Applicability. The requirements of the Geologic Hazard Overlay District shall apply to all uses and development proposed within any steep slope, landslide-prone area, or subsidence-prone area, as depicted on the Geologic Hazard Maps adopted by the [Governing Body]. Land within this overlay district may be used only under the conditions of this district and the underlying zoning districts. COMMENT: Mapping of geologic hazards can be time consuming and expensive. Some general information resources are available to aid municipalities in preparing overlay district maps. U.S.G.S. topographic maps are readily obtainable for identifying elevation contours. Landslide susceptibility maps and deep mine maps prepared by U.S.G.S. were reproduced by the Allegheny County Planning Department in the late 1970s for some areas of the County, and are also available on 7.5 minute quadrangle sheets. These maps may need updating, however. When complete, the County's geographic information system (GIS) should also be helpful to municipalities in identifying geologic hazard areas. Until better information becomes available, municipalities should err on the safe side and include areas where there is even a slight possibility that a hazard exists. In addition, municipalities may want to provide for staff recommendations regarding areas that are not included within mapped areas on the overlay district maps. Maps should be reviewed periodically (annually?) and adjusted as necessary. C.Definitions. For the purposes of these Geologic Hazard Overlay District requirements, the terms below shall have the meanings ascribed to them as follows: "Geologic Expert" means a registered professional or a geotechnical consultant with training and experience in geology, engineering or related field, with appropriate professional insurance certification. COMMENT: Municipalities may wish to develop a list of qualified experts rather than leaving this to case by case decisions. "Geologic Hazard Areas" means steep slopes, landslide-prone areas and subsidence-prone areas. "Landslide-Prone Areas" means any geologic formation which is especially susceptible to landslides due to the presence of unstable rock formations or soil types. "Steep Slopes" shall include: (a) moderately steep slopes from sixteen (16) to twenty-five (25) percent; (b) steep slopes exceeding twenty-five (25) percent; and very steep slopes exceeding forty (40) percent between adjacent contour lines on U.S.G.S. topographic map, measured over a horizontal distance of one hundred (100) feet. COMMENT: The slope categories should be evaluated by individual municipalities based on their topographic characteristics. For example, a particular municipality may customarily allow development on slopes of less than 25 percent and may wish to delete "moderately steep slopes" as a regulated category. "Subsidence-Prone Areas" means areas above active and abandoned mining cavities. D.Permitted Uses. Any use classified as a permitted use, conditional use, or special exception in an underlying zoning district may be allowed within a Geologic Hazard Overlay District, subject to the additional open space standards set out in Subsection F, and the Steep Slope Development standards in Section of the Subdivision and Land Development Ordinance. E.On-Site Investigation and Reporting Requirements. All applications submitted for approval of any use allowed in the Geologic Hazard Overlay District shall be accompanied by a Geologic Hazard Investigation Report. The Geologic Hazard Report shall be prepared by a "geologic expert," based on an investigation of the site of the proposed use or development, and shall contain the following minimum information, unless municipal staff determines that some of the information is unnecessary due to the scope and nature of the proposed development: (1)The boundaries of any Geologic Hazard Overlay Districts as depicted on Geologic Hazard Maps adopted by the [Governing Body] or if no such maps have been adopted, any geologic hazard areas found to exist on an actual investigation of the site; (2)Topographic contours lines at 1 foot intervals for the subject site before and after the completion of the proposed development; (3)A soils survey and geologic evaluation, including a narrative description of any conditions or factors which are relevant to the possibility of landslides or subsidence caused by development of the site. (4)A description of subsurface conditions, including the depth, location and characteristics of any mines which underlie the subject property; (5)A summary of the records, if any, of the Pennsylvania Department of Environmental Resources, Bureau of Mining and Reclamation, Division of Mine Subsidence Insurance and Mine Subsidence Regulations, regarding the location, depth and physical characteristics of any mine which underlies the subject property or adjacent properties; (6)A statement disclosing whether the subject property, or any adjacent properties, have any history of landslides or subsidence; and (7)Recommendation as to whether the site can be made safe for the proposed use, including any specific recommended construction or control techniques. (8)If the recommendation, in subsection (7) above, is that the site is not safe, a plan and specifications detailing how the applicant proposes to make the site safe for the proposed use, and protect adjacent properties from potential safety hazards must be included. COMMENT: Applicants in subsidence-prone areas are encouraged to contact the Pennsylvania Department of Environmental Resources, Bureau of Mining and Reclamation, Division of Mine Subsidence Insurance and Mine Subsidence Regulations about the location, depth and physical characteristics of any mine which may underlie the subject property or adjacent properties and the likelihood of mine subsidence occurring in the pertinent area. F.Open Space Requirements. The following portions of a development site within a Geologic Hazard Overlay District shall be reserved as open space and may not be graded or stripped of vegetation: (1)60 percent of any Moderately Steep Slope; (2)85 percent of any Steep Slope area; (3) 100 percent of any Very Steep Slope area; and (4)100 percent of any landslide-prone or subsidence-prone area unless the applicant demonstrates that any hazards will be corrected through engineering measures which are deemed satisfactory by the Municipal Engineer or consultants hired by the [Municipality] to review the engineering proposal. G.Warning and Disclaimer of Liability. These regulations do not imply that areas outside any designated Geologic Hazard Overlay District, or that uses permitted within such District, will be free from landslides or subsidence damage. These regulations shall not create liability on the part of the [Municipality] or any officer or employee thereof for any damage that results from reliance on this Zoning Ordinance or any decision lawfully made hereunder. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Steep Slope Development Standards COMMENT: These model regulations are companion regulations to establish subdivision and land development standards for development proposed in the "Geologic Hazard Overlay District." (See immediately preceding these model regulations.) These model steep slope development standards were adapted from Pittsburgh's Development Standards and Cincinnati's Hillside Development Guidelines. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE [SUBDIVISION AND LAND DEVELOPMENT ORDINANCE]; PROVIDING FOR STEEP SLOPE DEVELOPMENT STANDARDS; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR COMPATIBILITY OF STRUCTURES; PROVIDING FOR RELATIONSHIP TO BROW; PROVIDING FOR RIDGELINES; PROVIDING FOR RELATIONSHIP TO FOOT; PROVIDING FOR SCALE; PROVIDING COLOR AND TEXTURE; PROVIDING FOR STREETS AND DRIVEWAYS; PROVIDING FOR PARKING AND LOADING; PROVIDING FOR STORMWATER MANAGEMENT, EROSION AND SEDIMENTATION CONTROL; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to prevent damage to life and property from landslides, flooding, erosion, subsidence and other dangers that could result from new development located on or near steep slopes; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Subdivision and Land Development Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This section is intended to protect natural environmental and scenic resources and to ensure that development does not result in erosion and in flooding during the site preparation and development process. B.Applicability. No permits shall be issued for any clearing, grading or construction proposed on any Steep Slope unless the Municipality determines that the proposed land development conforms to the standards in this Section. C.Compatibility of Structures with Topography. Structures shall be designed in a manner that requires a minimum amount of alteration to the steep slope and that otherwise complies with the grading standards in Section of this Subdivision and Land Development Ordinance. Except where a geologic hazard investigation report recommends otherwise, split levels or terracing shall be used, and structures shall be sited on existing ledges or other relatively level areas of the site. Figure 1: Steep Slope Development Standards D.Relationship to Brow. The brow of the steep slope is that portion which forms the horizon when viewed from below or afar. Wherever possible, development shall occur on the most level land back from the brow or on the steep slope itself. E.Ridgelines. Development should not protrude significantly above the natural ridgeline as seen from major public roadways or viewing places. Rooftops, rooftop equipment (including but not limited to satellite dishes, solar panels, and air conditioning units), deck support structures and trash receptacles shall be adequately screened so they are not visible from major public roadways or viewing places. F.Relationship to Foot. The foot of a steep slope marks the transitional point between valley floor and steep slope. The majority of the steep slope foot shall not be obscured by a structure. When a street ends at a steep slope foot, the foot shall not be obscured at all when viewed from that street, except as necessary to accommodate structures of community significance. COMMENT: Architectural perspectives or drawings for a proposed building should be required in order for the municipality to evaluate compliance with these standards. G.Scale. Development should relate to the scale of steep slope vegetation, fitting within, rather than towering above the trees. High rise and high bulk structures are not appropriate on steep slopes as their scale promotes those structures rather than the steep slope as the dominant feature. When structures are dominant the steep slope character is irreversibly altered. H.Color and Texture. The color and materials used for structures should blend harmoniously with the natural colors of the steep slope. I.Streets and Driveways. Vehicular access ways should be limited in width to that which is necessary for emergency vehicles and traffic volumes. Streets and driveways should parallel the natural contours created by the terrain. J.Parking and Loading. Parking and loading areas shall be provided within the structure or on the uphill side behind buildings (see figure below). Figure 2: Location of Parking Areas Required Prohibited K.Stormwater Management, Erosion and Sedimentation Control. Particular caution shall be taken to prevent increases in the rate of stormwater runoff and erosion downslope of any steep slope development site. An approved stormwater management plan and an erosion and sediment control plan meeting the requirements of the Municipality's Subdivision and Land Development Ordinance shall be submitted before any use is approved under the provisions of this Subdivision and Land Development Ordinance. COMMENT: The references to a municipality's stormwater management and erosion control regulations should be revised if necessary to reference separate ordinances. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Tree, Vegetation and Wildlife Protection COMMENT: Trees, vegetation and wildlife are natural resources that many municipalities take for granted. Municipalities should establish strong goals to protect these resources and if possible conduct an inventory of significant or endangered species within a particular municipality. The Allegheny County Planning Department is currently undertaking an inventory of significant natural areas which may prove useful to municipalities in preparing more detailed inventories for their municipality. The following model regulations are suggested as amendments to a municipality's subdivision and land development ordinance but may also be appropriate as amendments to a municipality's logging ordinance (if one exists). A separate ordinance may be desirable in order to protect trees or habitats that are threatened by clearing or logging activities that are not regulated under a municipality's subdivision and land development ordinance. Ordinance No. AN ORDINANCE OF [MUNICIPALITY] AMENDING THE [SUBDIVISION AND LAND DEVELOPMENT ORDINANCE]; PROVIDING FOR TREE, VEGETATION AND WILDLIFE PROTECTION; PROVIDING FOR PURPOSES OF THE ORDINANCE; PROVIDING FOR APPLICABILITY; PROVIDING FOR SIGNIFICANT TREES, VEGETATION AND WILDLIFE HABITATS; PROVIDING FOR EXEMPTIONS; PROVIDING FOR PROTECTION AND REPLACEMENT STANDARDS; PROVIDING FOR SEVERABILITY; AND PROVIDING FOR AN EFFECTIVE DATE. Whereas, the [Municipality] has prepared a comprehensive plan; Whereas, the goals, policies and objectives of the comprehensive plan provide that the character, location and magnitude of development should be carefully reviewed to determine the impact of proposed development; and Whereas, the [Municipality] desires to protect significant trees, vegetation and wildlife habitat that could otherwise be threatened by the occurrence of new development; NOW THEREFORE BE IT ENACTED AND ORDAINED by the [Governing Body] of [Municipality] as follows. Section 1. The Subdivision and Land Development Ordinance of [Municipality] is hereby amended to add the following to [section of ordinance where amendment is appropriate]: A.Purpose. This Section is intended to protect significant trees, vegetation and wildlife that could be threatened during and as a result of new development. B.Applicability. All persons engaging in land development activities shall minimize any threat to significant trees, vegetation and wildlife to the greatest extent practicable. C.Significant Trees, Vegetation and Wildlife Habitats. Existing trees, vegetation and wildlife habitats are an important contribution to the natural environment of [Municipality]. The protection standards of this Section shall apply to the following types of significant trees, natural vegetation and wildlife habitats: (1)Any existing tree having a diameter at breast height of twelve inches (12") or greater; COMMENT: Twelve inches is a commonly used standard; however, it may need to be modified to reflect local conditions. (2)Existing, healthy specimens of the following significant plant species which are considered desirable species in [Municipality] or which are threatened or endangered, regardless of size or diameter: a.Trillium b. [list others] (3)Wildlife habitats of the following threatened or endangered species: a. . . . b. . . . (4) Identified significant natural areas. D.Exemptions. The protection standards in Subsection E below shall not apply to: (1)The removal of dead or naturally fallen trees or vegetation, or trees or vegetation that the Municipality finds to be a threat to the public health, safety or welfare; (2)The limited removal of trees or vegetation necessary to obtain clear visibility at driveways, intersections, or for the purpose of performing field survey work; (3)The removal of trees or vegetation on land zoned or lawfully used for: a.Agricultural activities, including tree farms and forestry management practices; b. Single-family or two-family dwelling units; c.Commercial garden centers, greenhouses or nurseries; or d.Utilities or public works projects. E. Protection, Relocation and Replacement Standards. (1)All land development, including earthmoving activities, shall be designed to minimize the removal of significant trees and vegetation and the disturbance of wildlife habitats, through the use of clustering, transferable development rights, relocation of endangered or threatened wildlife, replacement of damaged species, or other measures which are approved by the [Governing Body or Planning Commission -- whichever is responsible for land development approvals]. (2)All existing significant trees and vegetation on the subject property shall be clearly identified on a landscaping plan which shall be submitted with a preliminary plat or land development plan. (3)All known wildlife habitats of threatened or endangered species shall be clearly identified on a plan submitted with a preliminary plat or land development plan. (4)Existing significant trees and vegetation and identified wildlife habitats located on the site of any proposed development shall be preserved, unless the applicant demonstrates that no practical alternatives exist and that removal is necessary to allow building foundations, accessory structures, required parking areas, driveways, sidewalks, utilities, or other improvements. If the applicant claims that "no practical alternatives" exist, an alternative development plan utilizing the "cluster development option" [described in Section of the Zoning Ordinance] shall be submitted and the applicant shall explain why this option is not a practical alternative. COMMENT: If a municipality's zoning ordinance does not include a cluster option, municipalities should consider adding one, using the model regulations in this Chapter. (5)A (10?) percent reduction in the number of required parking spaces required on the site shall be allowed to the extent that reduction in the amount of required pavement will preserve significant trees or vegetation or wildlife habitats. COMMENT: This provision should also be referenced in the municipality's parking standards. (6)Significant trees and vegetation may be counted toward the minimum landscaping required under the Zoning Ordinance. (7)Where any significant tree or vegetation must be removed, it shall either be transplanted, if the applicant demonstrates that transplanting is feasible, or replaced with comparable trees or vegetation. The recommended transplanting techniques described in the Tree and Shrub Transplanting Manual, by the International Society of Arboriculture, shall be used as a guide in determining if a tree can be feasibly transplanted. (8)Protective barriers shall be erected around all significant trees, vegetation, wetlands, and wildlife habitats in areas of the site where land alteration and construction activities are proposed. Barriers shall be designed to prevent the compaction or disturbance of roots within the "drip line" of any tree. Barriers shall remain in place until land alteration and construction activities are completed. Section 2. If any section or specific provision or standard of these regulations that now exists or may exist in the future is found by a court to be invalid for any reason, the decision of the court shall not affect the validity of any other section, provision, or standard of these regulations except the provision in question. The other portions of the regulations not affected by the decision of the court shall remain in full force and effect. Section 3. This Ordinance shall be effective upon its adoption in accordance with applicable law. Part 3. ENVIRONMENTAL PROTECTION BIBLIOGRAPHY American Planning Association's Planning Magazine, (September 1990). Anderson, R., American Law of Zoning (2d ed 1977). Aspen (Colorado) Land Use Regulations, Chapter 24 of the Aspen Municipal Code (effective 5/25/88), regulating development in environmentally sensitive areas including steep slopes, stream margins and mountain view planes. Babcock, R., and Larsen, W., Special Districts:The Ultimate In Neighborhood Zoning (Cambridge, MA: Lincoln Institute of Land Policy, 1990) Blackwell, Robert J. "Overlay Zoning, Performance Standards and Environmental Protection After Nollan," Chapter 18 of the 1990 Zoning and Planning Law Handbook, by Mark S. Dennison, ed. (New York, New York: Clark Boardman Company, Ltd., 1990). Bosselman, Fred, and D. Feurer and C. Siemon, The Permit Explosion: Coordination of the Proliferation, (The Urban Land Institute, 1976), discussing various state, regional and local land use permitting procedures. Briggs, R., J. Pomeroy, and W. Davies, Landsliding in Allegheny County, Pennsylvania, (Geological Survey Circular 728, U. S. Department of the Interior). Chapin, F. Stuart, Jr. and Edward J. Kaiser, "Natural Environmental Inventory and Analysis," in Urban Land Use Planning, (Urbana and Chicago, Illinois: University of Illinois Press, 3d ed., 1979). Coughlin, R., J. Denworth, J. Keene, and J. Rogers, Guiding Growth, Building Better Communities and Protecting Our Countryside: A Planning and Growth Management Handbook for Pennsylvania Municipalities (Pennsylvania Environmental Council, 1991). Greater Pittsburgh International Airport Impact Area Plan (July 1988). Hooten, Anthony J., "Fairfax County, Virginia: A case-study for an ecological-resource inventory program for use by local governments," 33/34 Forest Ecology Management, 253-269 (1990). Jaffe, M. and F. DiNovo, Local Groundwater Protection (American Planning Association, 1986). Kaiser, Edward J., Karl Elfers, Sidney Cohn, Peggy Reichert, Maynard M. Hufschmidt, and Raymond E. Stanland, Jr., Promoting Environmental Quality Through Urban Planning and Controls, EPA-600/5-73-015 (Washington, D.C.: U.S. Government Printing Office, February, 1974). Kendig, L., Performance Zoning (American Planning Association, 1980). Knack, Ruth, "Selling Cluster" Planning (American Planning Association, September 1990), pp. 22-23. Lake County Department of Planning, Zoning & Environmental Quality, Lake County Zoning Ordinance (Lake County Regional Plan Commission, 1986). Lewis, S., "The Town That Said No To Sprawl," Planning Magazine (Chicago: American Planning Association, April 1990), pp. 14-19. Marsh, Lindell, "An Approach for Reconciling Development and Wetlands/Wildlife Conservation," Urban Land (Urban Land Institute, July 1989). Massachusetts Department of Environmental Management, Center for Rural Massachusetts, Dealing with Change in The Connecticut River Valley: A Design Manual for Conservation and Development (Lincoln Institute of Land Policy and the Environmental Law Foundation, 1990). National Water Commission, Water Policies for the Future: Final Report to the President and to the Congress of the United States by the National Water Commission (Washington, D.C.: U.S. Government Printing Office, 1973). Pennsylvania Department of Environmental Resources, Storm Water Management Guidelines and Model Ordinances (1985). Pennsylvania Department of Community Affairs, Suggested Provisions Meeting the Minimum Requirement of Section 60.3(b),(c) and (d) of the National Flood Insurance Program and the Pennsylvania Flood Plain Management Act (1978-166), 1988. Pennsylvania Department of Environmental Resources, Wetlands Protection: A Handbook for Local Officials (Environmental Planning Information Series Report #7, May 1990). Pennsylvania Department of Environmental Resources, Soil Erosion and Sedimentation Control Manual (January 1, 1974). Pennsylvania Department of Environmental Resources, Erosion and Sediment Pollution Control Program Manual (April, 1990). Siemon, Charles L. and Michelle J. Zimet, "Carrying Capacity Planning: Rx for the Future?" in Implementation of the 1985 Growth Management Act: From Planning To Land Development Regulations, Fort Lauderdale: FAU/FIU Joint Center for Environmental and Urban Problems, Monograph #89-1, 1989. Stein, Ronald M., "A California Approach to Determine Whether An Environmental Impact Report is Required," proceedings of the Conference of National Institute of Municipal Law Officers, September 20-23, 1987. Tarlock, Daniel A., "New Duties on Developers to Avoid Wetland Use" in Zoning and Planning Law Report, Vol. 12, No. 10 (November 1989). The New Jersey State Planning Commission, The Preliminary State Development and Redevelopment Plan for the State of New Jersey, Volume 1 (November 1988). U.S. Fish and Wildlife Service, Mitigation Banking, (Biological Report 88(41), July 1988). For more information on causes of landsliding in Allegheny County, see the U.S. Department of Interior's "Geological Survey Circular 728 -- Landsliding in Allegheny County." Environmental Protection And Hazard Control Environmental Protection And Hazard Control Improving Local Development Regulations: Page I-20 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-19 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-1 Model Regulations Environmental Protection Model Regulations Environmental Protection Improving Local Development Regulations: Page I-17 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-17 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-21 Model Regulations Site Capacity Analysis Model Regulations Site Capacity Analysis Improving Local Development Regulations: Page I-36 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-37 Improving Local Development Regulations: Page I-22 A Handbook for Municipal Officials Model Regulations Cluster Development Model Regulations Cluster Development Improving Local Development Regulations: Page I-40 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-41 Improving Local Development Regulations: Page I-38 A Handbook for Municipal Officials Model Regulations Grading Model Regulations Grading Improving Local Development Regulations: Page I-44 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-45 Improving Local Development Regulations: Page I-42 A Handbook for Municipal Officials Model Regulations Flood Plains Model Regulations Flood Plains Improving Local Development Regulations: Page I-50 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-51 Improving Local Development Regulations: Page I-46 A Handbook for Municipal Officials Model Regulations Stormwater Management Development Model Regulations Stormwater Management Development Improving Local Development Regulations: Page I-56 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-57 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-52 Model Regulations Erosion Control Model Regulations Erosion Control Improving Local Development Regulations: Page I-62 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-61 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-58 Model Regulations Geologic Hazards Model Regulations Geologic Hazards Improving Local Development Regulations: Page I-68 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-67 Improving Local Development Regulations: Page I-63 A Handbook for Municipal Officials Model Regulations Steep Slopes Model Regulations Steep Slopes Improving Local Development Regulations: Page I-74 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-73 Improving Local Development Regulations: Page I-69 A Handbook for Municipal Officials Model Regulations Trees, Vegetation & Wildlife Model Regulations Trees, Vegetation & Wildlife Improving Local Development Regulations: Page I-78 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-79 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-75 Bibliography Environmental Protection and Hazard Control Bibliography Environmental Protection and Hazard Control Improving Local Development Regulations: Page I-82 A Handbook for Municipal Officials Improving Local Development Regulations: A Handbook for Municipal Officials Page I-81 Improving Local Development Regulations: A Handbook for Municipal Officials Page I-80