ARTICLE IV

November 22, 2008

Please use Page Up or Page Down to Scroll

ARTICLE IV
Natural Features Protection Standards

~ 287-11. Statement of intent

The standards and requirements in this article are intended to afford appropriate levels of protection to those natural features within Downingtown Borough that represent significant resource opportunities to the borough and its surrounding region or which, when subject to undue disturbance, may constitute threats to public health, safety and welfare. The borough considers adherence to these standards a basic prerequisite to any land use, development or disturbance otherwise authorized under this Zoning Ordinance or other regulations and has designed the balance of the Zoning Ordinance to work in harmony with the terms of this article.

~ 287-12. Floodplain District.

A. Intent. The intent of this section is to:

(1) Promote the general health, welfare and safety of the community.

(2) Encourage the utilization of appropriate construction practices and site design techniques in order to prevent or minimize flood damage in the future.

(3) Minimize danger to public health and safety by protecting water supply, sanitary sewage disposal and natural drainage.

(4) Protect the quality and quantity of surface and subsurface water supplies adjacent to and underlying floodplain areas.

(5) Contribute to the protection of stream waters against sedimentation, the prevention of streambank erosion, the maintenance of cool water temperatures and the preservation of fish and wildlife habitats through the protection of trees and other riparian vegetation.

(6) Maintain the scenic and aesthetic character of the

Brandywine Creek and its tributary streams.

(7) Reduce financial burdens imposed on the community, borough government and emergency services by preventing the unwise design and construction of development in areas subject to flooding.

(8) Fulfill the responsibility of the borough as a trustee of the people's right to clean air, pure water and the preservation of the natural, scenic, historic and aesthetic values of the environment pursuant to Article I, Sec. 27, of the Pennsylvania Constitution.

B. Applicability.

(1) Provisions of all other codes, ordinances and regulations shall be applicable insofar as they are consistent with the provisions of this chapter and the need of Downingtown Borough to minimize the hazards and damage resulting from flooding.

(2) A use and occupancy permit shall be required before any development is undertaken within the Floodplain District. Prior to the issuance of such permit, the Zoning Officer shall review the permit application to determine if all other permits required by Pennsylvania or federal law have been obtained.

C. Establishment of the Floodplain District.

(1) [Amended 11-6-1996 by Ord. No. 96-16] The Floodplain District shall include all areas subject to inundation by the waters of the base flood elevation. The source of this delineation shall be the Flood Insurance Study for the Borough of Downingtown, Chester County, Pennsylvania, as prepared by the Federal Emergency Management Agency, Federal Insurance Administration, dated November 20, 1996 (No. 420275D), or the most recent revision thereof. The Floodplain District shall be comprised of three subdistricts, as follows:

(a) Floodway (F1): that portion of the Floodplain District required to carry and discharge the waters of the base flood elevation without increasing the water surface elevation at any point more than one foot above existing conditions, as demonstrated in the Flood Insurance Study referenced above and shown on the accompanying Flood Insurance Rate Map (FIRM).

(b) Floodfringe (F2): those portions of land within the Base Flood Elevation not included in the floodway. The basis for the outermost boundary of this District shall be the Base Flood Elevation in the flood profiles of the above-referenced Flood Insurance Study and as shown on the accompanying Flood Insurance Rate Map (FIRM).

(c) Approximated Floodplain (F3): those portions of land within the Floodplain District subject to inundation by the base flood elevation, where a detailed study has not been performed, but where a base flood elevation boundary has been approximated by the Flood Insurance Study and Flood Insurance Rate Map (FIRM) referenced above. When available, information from other federal, state or other available sources shall be used to determine a floodway area. Where the specific base flood elevation cannot be determined for this area using other sources of data, such as the Flood Plain Information Report on the East Branch Brandywine Creek (United States Army Corps of Engineers, December 1970), the United States Geological Survey Flood-Prone Quadrangles, etc., then the applicant for the proposed use, development and/or activity shall determine this elevation in accordance with hydrologic and hydraulic engineering techniques. Hydrologic and hydraulic analyses shall be undertaken only by a registered professional engineer, who shall certify as to the validity of the technical concepts, studies, analyses, computations, etc. Such analyses shall be submitted in sufficient detail to allow a thorough technical review by the borough.

(2) Changes.

(a) The delineation of the Floodplain District may be revised, amended and modified by the Borough Council in compliance with the National Flood Insurance Program when:

[1] There are changes through natural or other causes.

[2] Changes are indicated by future detailed hydrologic and hydraulic studies.

(b) All such changes shall be subject to the review and approval of the Federal Insurance Administrator.

D. Boundary disputes.

(1) In case of any dispute concerning the exact location of the Floodplain District, the party disputing the boundaries shall submit to the Zoning Officer a detailed on-site survey of the land in question made by a registered professional engineer or registered surveyor.

(2) Upon receipt of an on-site survey, the Zoning Officer shall immediately submit the survey to the Borough Engineer and the Borough Planning Commission for their recommendations. Within 30 days of his receipt of the survey, the Zoning Officer shall, by certified mail, notify the party disputing the district boundaries of his determination.

(3) Any party aggrieved by a decision of the Zoning Officer may appeal to the Zoning Hearing Board under the provisions of Article XXII of this chapter. The burden of proof shall be on the appellant

E. Uses permitted in the Floodway (F1). The following uses, exclusive of buildings, are permitted in the floodway. However, within any Floodway (F1) Area, no new construction, development, use, activity or encroachment shall be permitted unless the effect of such development on flood heights is fully offset by accompanying stream improvements which have been approved by all appropriate local and/or state authorities. When a developer proposes to offset the effects of development in the Floodway by construction of stream improvements, he shall submit an engineering study prepared by a registered professional engineer which fully evaluates the effects of such construction. The report shall use the base flood as herein defined as the basis of analysis. Those adjacent communities within the stream's watershed that may be affected by the proposed stream improvements shall be notified by the applicant, by certified mail, of all such intended activities prior to any alteration or relocation of a watercourse. The applicant shall provide copies of such notification to the borough for submission to the Pennsylvania Department of Community Affairs and the Federal Insurance Administrator. In addition, the applicant shall assure the Borough of Downingtown, in writing, that the floodcarrying capacity within the altered or relocated portion of the watercourse in question will be maintained.

(1) Uses permitted as of right:

(a) Agricultural uses, such as general farming, pasture, orchard, grazing, outdoor plant nurseries and truck farming.

(b) Selective cutting of trees, in accordance with the definition of selective cutting in ~ 287-7 of this chapter, and provided further that desirable mature shade trees are not totally eliminated, that particular attention is paid to retaining such trees within 25 feet of any stream and that no such trees growing within or upon the streambank shall be removed unless dead, diseased or damaged and threatening the stability of the bank.

(c) Recreational uses, such as park, camp and picnic grounds; golf courses; golf driving ranges; archery and shooting ranges; hiking and riding trails; hunting and fishing areas; game farms; fish hatcheries; and swimming areas.

(d) Wildlife sanctuaries, nature preserves or arboretums.

(e) Circuses, festivals and similar transient amusement enterprises, but limited in duration to not more than one week per calendar year.

(f) An area comprising no more than 3/4 of the required minimum lot area for any lot contiguous to the floodway, and provided that no building or structure and no sanitary drainage field shall be placed within 50 feet of the Floodplain District boundary line.

(g) Sealed water supply wells and water pipelines.

(h) Sanitary sewer lines and sewage pumping stations; storm and sanitary sewer outlets, which shall take the shortest route across the district to the point of discharge.

(i) Nonstructural accessory uses customarily incidental to any of the above permitted uses.

(2) Uses permitted by special exception. The following uses are permitted within the floodway only upon the granting of a special exception by the Zoning Hearing Board. In considering any application for a special exception within the floodway, the Board shall be guided by the factors cited in Subsection L(2) below and by the standards for special exception contained in ~ 287-145 of this chapter.

(a) Pervious parking area, as an accessory use customarily incidental to any of the foregoing permitted uses.

(b) Water-related uses and activities, such as docks or piers.

(c) Construction of dams or culverts or of necessary crossings of the floodway by railroads, roads, bridges or utility transmission lines.

(d) Sewage treatment plants; water treatment plants.

(e) Storage of material and equipment, provided that it is not buoyant, flammable or explosive; that it is not prohibited by Subsection G below; and that it is not subject to major damage by flooding, and provided that such material and equipment is firmly anchored to prevent flotation or movement and/or can be readily removed from the area within the time available after a flood warning.

(3) The following shall not be placed or caused to be placed in the designated floodway:

(a) Fences (except two-wire fences).

(b) Other matters which may impede, retard or change the direction of the flow of water or that will catch or collect debris carried by such water or that are placed where the natural flow of the stream or floodwaters would carry the same downstream to the damage or detriment of either public or private property adjacent to the floodplain. The placement of mobile homes shall be prohibited in any designated floodway.

F. Uses permitted in Floodfringe (F2) and Approximated Floodplain (F3) Areas.

(1) The following uses are permitted in the Floodfringe (F2) and Approximated Floodplain (F3).

(a) Uses permitted as of right:

[1] Uses permitted as of right within the floodway, as provided in Subsection E above.

[2] Sewage treatment plants and water treatment plants, subject to the approval of the Department of Environmental Resources, provided that such facilities shall be designed and constructed to eliminate infiltration of floodwaters into the system and discharges from the system into the waters of the commonwealth.

[3] Nonstructural accessory uses, including pervious parking, customarily incidental to any of the foregoing permitted uses.

[4] Detention or retention basins for the control of stormwater, when part of a borough-approved stormwater management plan.

(b) Uses permitted by special exception:

[1] Any use not permitted as of right by Subsection F(1)(a) above which is authorized as a special exception in Subsection E(2) above, when in accordance with the terms specified therein.

(2) When a developer proposes to construct stream improvements or to install fill or alter or relocate a watercourse, he shall submit an engineering study prepared by a registered professional engineer which fully evaluates the effects of such construction. The report shall use the base flood elevation, as herein defined, as the basis of analysis. Those adjacent communities within the stream's watershed that may be affected by the proposed stream improvements shall be notified by the applicant, by certified mail, of all such intended activities prior to any alteration or relocation of a watercourse, and the applicant shall provide copies of such notification to the borough for submission to the Pennsylvania Department of Community Affairs and the Federal Insurance Administrator. In addition, the applicant shall assure the borough, in writing, that the flood-carrying capacity within the altered or relocated portion of the watercourse in question will be maintained.

(3) All uses, activities and other developments shall be undertaken in strict compliance with the floodproofing and related provisions contained herein and in all other applicable codes, ordinances and regulations.

G. Activities specifically prohibited in the Floodplain District. Any use or activity not authorized as a permitted use under the terms of Subsections E and F above shall be prohibited within the Floodplain District. In particular, the following activities, whether proposed in conjunction with a permitted use or otherwise, shall not occur in any portion of the Floodplain District:

(1) Clear-cutting of trees.

(a) Clear-cutting of trees, as defined in ~ 287-7 of this chapter, or the clearing of vegetation, except where such clearing is necessary:

[1] To prepare land for a use permitted by Subsections E or F above or by action of the Zoning Hearing Board. Where clear-cutting is proposed in conjunction with the site of a stormwater management basin, such clear-cutting shall be authorized only when in accordance with an approved plan for development which the basin is to serve.

[2] As a reforestation measure.

[3] As a means to eliminate dead, diseased or hazardous tree stands.

(b) Where a clear-cutting operation is deemed permissible for one of the above reasons, under no circumstances shall it be conducted within 25 feet of a stream.

(2) Sod farming.

(3) Storage of any material which, if inundated, would float or of any flammable or toxic material or any other material which, if inundated or otherwise released to the stream, would degrade or pollute the stream or cause damage if swept downstream.

(4) Storage of and the construction, enlargement or expansion of any structure which would be used for the production, storage or maintenance of a supply of the following toxic chemicals, which are listed in Act 166 of 1978, the Pennsylvania Flood Plain Management Act, and are dangerous to human or animal life:

(a) Acetone.

(b) Ammonia.

(d) Calcium carbide.

(e) Carbon disulfide.

(f) Celluloid.

(g) Chlorine.

(h) Hydrochloric acid.

(i) Hydrocyanic acid.

(j) Magnesium.

(k) Nitric acid and oxides of nitrogen.

(l) Petroleum products (gasoline, fuel oil, etc.).

(m) Phosphorus.

(n) Potassium.

(o) Sodium.

(p) Sulphur and sulphur products.

(q) Herbicides or pesticides, including insecticides, fungicides and rodenticides.

(r) Radioactive substances, insofar as such substances are not otherwise regulated.

(s) Any other dangerous materials or substances regulated by the appropriate federal or state agencies or any materials or substances which may be added to the list contained in Act 166 of 1978 subsequent to enactment of this chapter or which may be deemed similar thereto.

(5) Installation of subsurface sewage disposal areas.

(6) The construction, enlargement or expansion of mobile homes, mobile home parks, mobile home subdivisions, manufactured homes or manufactured home parks or subdivisions.

(7) The construction, enlargement or expansion of hospitals (public or private).

(8) The construction, enlargement or expansion of nursing homes (public or private).

(9) The construction, enlargement or expansion of jails or prisons.

(10) Junkyards.

H. Nonconforming structures and uses in the floodplain district. Nonconforming structures and uses of land within the Floodplain District shall be regulated under the provisions of Article XX of this chapter, but the following additional regulations also shall apply:

(1) Existing nonconforming structures or uses located in the Floodway (F1) shall not be expanded or enlarged.

(2) The modification, alteration, repair, reconstruction or improvement of any kind to a nonconforming structure or use in a Floodway (F1) and the modification, expansion, enlargement, alteration, repair, reconstruction or improvement of any kind to a nonconforming structure or use located in a Floodfringe (F2) or Approximated Floodplain (F3) may occur only when authorized as a special exception by the Zoning Hearing Board under the provisions of Article XXII of this chapter. In considering requests for such special exceptions, the Zoning Hearing Board shall apply the following standards and criteria:

(a) No modification, alteration, repair, reconstruction or improvement of any structure in the Floodway (F1) shall be permitted that will cause any increase in the one-hundred-year-flood elevation.

(b) The proposed change is consistent with the spirit, purpose and intent of this chapter.

(c) The proposed use is feasible and suitable in relation to the land use capabilities of the property in question, particularly its capabilities in terms of a suitable water supply, drainage, sewage disposal, topography, soil conditions and ecological consideration.

(d) The proposed change will serve the best interests of the borough, the convenience of the community, where applicable, and the public welfare.

(e) The adequacy of sanitation and public safety provisions, where applicable, is assured and a certificate of adequacy or permit for sewage and water facilities has been obtained from the Chester County Health Department or other appropriate governmental agencies required herein or deemed advisable by the Zoning Hearing Board.

(f) If improvements to the Floodway (F1) or any filling or alterations to the elevation of the ground in the Floodway (F1), Floodfringe (F2), or Approximated Floodplain (F3) or any alterations or relocations of any perennial stream are contemplated, the Zoning Hearing Board shall determine that the applicant has complied with the provisions of Subsections E and F above, with regard to the effect of such filling or alterations on base flood elevations and has notified, in writing, by certified mail, those adjacent communities within the stream's watershed that may be affected by such alterations and has submitted copies of such notification to the borough for submission to the Pennsylvania Department of Community Affairs and the Federal Insurance Administrator and has, in addition, obtained a permit from the Pennsylvania Department of Environmental Resources, Division of Dams and Waterway Management.

(g) Any permissible modification, alteration, repair, reconstruction, expansion or improvement of any kind to a nonconforming structure or use located in the Floodplain District to an extent or amount less than 50% of its market value shall be elevated and/or flood-proofed to the greatest extent possible.

(h) Any modification, alteration, repair, reconstruction, expansion or improvement of any kind to a nonconforming structure or use, regardless of location within the Floodplain District, to an extent or amount of 50% or more of its market value shall be undertaken only in full compliance with the provisions of this chapter and any other applicable ordinances. This includes structures which have incurred substantial damage regardless of the actual repair work performed. [Amended 11-6-1996 by Ord. No. 96-16]

(i) All structures shall be constructed and placed on the lot so as to offer the minimum obstruction to the flow of water and shall be designed to have a minimum obstruction effect upon the flow and height of floodwater.

(j) The Zoning Hearing Board shall have the right to waive any of the requirements of this Subsection H for any structure or site listed in or determined eligible for the National Register of Historic Places or the Pennsylvania Inventory or Register of Historic Places or its equivalent. In deciding upon any request for such a waiver, the Board shall be guided by the criteria in Subsection L below and shall follow the procedures for acting on special exceptions as specified in Article XXII of this chapter. Any requested waiver shall be submitted to the Downingtown Historical Society for review and recommendation on the appropriateness of the proposed activity in relation to the quality and integrity of the historic structure and the degree to which the requested waiver will be essential to preserving the structure. The Zoning Hearing Board also shall weigh the preservation benefits of the proposed activity against its potential impact on flood heights and velocities and the flood hazards attendant to the structure itself.

I. Modifications to the floodplain or stream courses.

(1) Any modifications required to the elevation of the ground in the Floodway (F1), Floodfringe (F2) or Approximated Floodplain (F3) or any alteration or relocation of any perennial stream required for the construction or conduct of permitted uses within the Floodplain District, including nonconforming uses, and any of the aforesaid modifications, alterations or relocations required in order to gain access across land in the Floodplain District shall be designed and constructed in accordance with the following;

(a) A plan shall be prepared and presented to the Borough Council (or Zoning Hearing Board in the case of special exception procedures relating to nonconforming uses) which shows or is accompanied by:

[1] The name and address of the applicant.

[2] The name and address of owner of land on which proposed construction is to occur.

[3] The site location.

[4] Base flood elevations.

[5] The name of the engineer or surveyor responsible for providing the information.

[6] A plan of the site, including plans of subdivisions or land developments lying partially in the Floodplain District, showing the exact size and location of the proposed construction, as well as any existing buildings or structures. This plan shall show the location of the proposed work with respect to the floodplain areas, proposed lots and sites, cuts, fills, flood- or erosion-protection facilities, areas subject to special deed restrictions and detailed information giving the location and elevation of proposed roads, bridges, pipes, stream alterations or relocations, public utilities and building sites. All such plans shall also show contours at intervals required by the Borough Subdivision and Land Development Ordinance and identify accurately the boundaries of the Floodplain District.

(b) The applicant shall notify, in writing, by certified mail, those adjacent communities within the stream's watershed that may be affected by modifications to the elevation of ground in the Floodplain District or by alterations or relocations of streams. The applicant also shall provide copies of the notification to the borough for submission to the Pennsylvania Department of Community Affairs and the Federal Insurance Administrator.

(c) The applicant shall submit a copy of a permit from the Pennsylvania Department of Environmental Resources, Division of Dams and Waterway Management, for the modifications to the grade or alterations or relocations to the stream or evidence from said Pennsylvania Department of Environmental Resources that such a permit is not required.

(d) Proposed fills shall meet the following minimum standards:

[1] Fill shall consist of soil or rock materials only. Sanitary landfills shall not be permitted.

[2] Fill material shall be compacted to provide the necessary stability and resistance to erosion, scouring or settling.

[3] Fill slopes shall be no steeper than one vertical on three horizontal, unless substantiating data justifying steeper slopes are submitted to and approved by the Zoning Officer.

[4] Fill shall be used only to the extent to which it does not adversely affect adjacent properties.

[5] Care shall be taken to prevent erosion and sedimentation due to proximity to the stream. The Borough Engineer shall approve the proposed erosion/sedimentation control methodology.

(2) Plans submitted under the provisions of this subsection shall be subject to the review and approval of the Borough Council according to procedures set forth in the Borough Subdivision and Land Development Ordinance.

J. Installation of utility facilities in Floodplain District. Where utility lines or on-site facilities are required to be installed or replaced in a Floodplain District, the following minimum standards shall apply:

(1) Water facilities. All new or replacement water facilities, whether public or private, shall be designed to minimize or eliminate infiltration of floodwaters into the system and be located and constructed to minimize or eliminate flood damages.

(2) Sanitary sewer facilities. All new or replacement sanitary sewer facilities, including all pumping stations and collection systems, whether public or private, shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into the floodwaters. In addition, they should be located and constructed to minimize or eliminate flood damage and impairment.

(3) Drainage. Storm drainage facilities, whether public or private, shall be designed to convey the flow of stormwater runoff in a safe and efficient manner.

(4) All other new or replacement public or private utilities and facilities shall be designed to minimize or eliminate infiltration of floodwaters into the system and be located and constructed to minimize or eliminate flood damages.

K. Minimum floodproofing standards. Where a special exception has been requested under the provisions of Subsection H above, in which it is anticipated that a structure or use will be modified, altered, repaired, reconstructed, expanded or improved in any way, or when a sewage treatment plant or pumping station or water treatment plant is contemplated under the provisions of Subsection F above or where a special exception or variance is granted under the provisions of Subsection L below, the following minimum standards shall apply to floodproofing:

(1) Within any Floodway (Fl), Floodfringe (F2) or Approximated Floodplain (F3), the lowest floor, including basement, of any new or improved residential structure shall be elevated at least 1 1/2 feet above the base flood elevation. Any new or improved nonresidential structure shall be elevated in the same fashion or the structure, together with attendant utility and sanitary facilities, shall be designed so that below the base flood elevation the structure is water tight, with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

(2) If fill is used to raise the finished surface of the lowest floor to the base flood elevation, such fill shall extend beyond a structure for a sufficient distance to provide acceptable access. For residential structures, fill shall extend laterally 15 feet beyond the building line from all points. For nonresidential structures, fill shall be placed to provide access acceptable for the intended use. At-grade access, with fill extending laterally 15 feet beyond the building line, shall be provided to a minimum of 25% of the perimeter of a nonresidential structure.

(3) All buildings and structures shall be firmly anchored, in accordance with accepted engineering practices, to prevent flotation, collapse and lateral movement, thus reducing the threat to life and property and decreasing the possibility of the blockage of bridge openings and other restricted sections of the watercourse.

(4) For all new construction and substantial improvements, fully enclosed areas below the lowest floor that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must be certified by a registered professional engineer and must meet or exceed the following minimum criteria:

(a) A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.

(b) The bottom of all openings shall be no higher than one foot above grade.

(c) Openings may be equipped with screens, louvers or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

(5) Electrical, heating, ventilation, plumbing and air-conditioning equipment and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

(6) All air ducts, large pipes and storage tanks located at or below the base flood elevation shall be firmly anchored to resist flotation.

(7) Plans filed for the purpose of determining compliance with these regulations shall include:

(a) The name and address of the applicant.

(b) The name and address of the owner of the land on which the proposed construction is to occur.

(d) The site location.

(e) A brief description of proposed work and estimated cost

(f) A plan of the site showing the exact size and location of the proposed construction, as well as any existing buildings or structures.

(8) Depending on the type of structure involved, the following information shall also be included in the application and maintained on record by the Zoning Officer:

(a) For structures to be elevated to the base flood elevation:

[1] A plan showing the size of the proposed structure and its relation to the lot where it is to be constructed.

[2] A determination of the base flood elevation and elevations of the existing ground, proposed finished ground and lowest floors, including basements, to be certified by a registered professional engineer or surveyor.

[3] Plans showing the method of elevating the proposed structure, including details of proposed fills, pile structures, retaining walls, foundations, erosion-protection measures, etc. These plans shall be prepared by a registered professional engineer or architect.

[4] Plans showing the methods used to protect utilities, including sewer, water, telephone, electric, gas, etc., from flooding to the base flood elevation at the building site.

(b) For structures to be floodproofed to the base flood elevation (nonresidential structures only):

[1] Plans showing details of all floodproofing measures, prepared by a registered professional engineer or architect, and showing the size of the proposed structure and its relation to the lot where it is to be constructed.

[2] A determination of the base flood elevation and elevations of existing ground, proposed finished ground, lowest floors and floodproofing limits, certified by a registered professional engineer or surveyor.

[3] A certificate, prepared by the registered professional engineer or architect who prepared the plans in Subsection K(8)(b)[1] above, that the structure in question, together with attendant utility and sanitary facilities, is designed so that:

[a] Below the base flood elevation, the structure is watertight, with walls substantially impermeable to the passage of water.

[b] The structure will withstand the hydrostatic, hydrodynamic, buoyant impact and other forces resulting from the flood depths, velocities, pressures and other factors associated with the base flood elevation.

L. Hardships.

(1) When the provisions of this ~ 287-12 are deemed by the applicant to be unreasonable or to create a substantial hardship, the applicant shall have a right to:

(a) In the case of applications for permitted uses under Subsection E or F above, make an appeal to the Zoning Hearing Board in accordance with the provisions of Article XXII of this chapter.

(b) In the case of an appeal to the Zoning Hearing Board for a special exception under the provisions of Subsection H above, supply additional testimony and evidence to the Zoning Hearing Board as part of his request for relief from such hardship.

(2) All decisions on such appeals shall adhere to the following criteria:

(a) The Zoning Hearing Board shall not grant a variance or special exception for any construction, development, use or activity within any floodway area that would cause any increase in the base flood elevation.

(b) The Zoning Hearing Board shall grant special exceptions only upon a showing of good and sufficient cause, a determination that failure to grant the special exception would result in substantial hardship to the applicant and a determination that the granting of a special exception will not result in increased flood heights, additional threats to public safety or extraordinary public expense or the creation of a nuisance, fraud on or victimization of the public or conflict with existing local laws or ordinances.

(c) The Zoning Hearing Board shall grant a special exception only upon determination that it is the minimum necessary to afford relief, considering the flood hazard. In any case where floodproofing will be required, the Board may prescribe strict compliance with the floodproofing standards of Subsection K of this section.

(d) The Zoning Hearing Board shall notify the applicant, in writing, over the signature of the Chairman of the Zoning Hearing Board, that the issuance of a decision to allow construction of a structure below the base flood elevation will result in increased premium rates for flood insurance and that such construction below the base flood elevation increases risks to life and property. Such notification shall be maintained with a record of all decisions, as required in Subsection L(2)(e) below.

(e) The Zoning Hearing Board shall maintain a record of all decisions, including justification for their issuance, and report such decisions issued to the borough for inclusion in the annual report submitted to the Federal Insurance Administrator.

(f) No special exception or variance shall be granted for any requirement pertaining to developments which may endanger human life as described in Subsection G(4), (6), (7), (8) and (9) of this section, in accordance with the Pennsylvania Flood Plain Management Act, P.L. 851, No. 166 of 1978, as amended.

(g) Upon receiving an application for a special exception or variance, the Zoning Hearing Board shall, prior to rendering a decision thereon, require the applicant to furnish such of the following material as is deemed necessary by the Board:

[1] Plans, in triplicate, drawn to scale, showing the nature, location, dimensions and elevation of the lot and existing and proposed uses; photographs showing existing uses and vegetation; soil types; and other pertinent information.

[2] A series of cross sections at twenty-five-foot intervals along the lot shoreline, showing the stream channel and elevation of adjoining land areas to be occupied by the proposed uses, and high-water information. Cross sections shall be field-run topography, based on a known United States Geological Survey benchmark.

[3] A profile showing the slope of the bottom of the channel.

[4] Specifications for building materials and construction, floodproofing, filling, dredging, grading, storage and water supply and sanitary facilities.

[5] A computation of the increase, if any, in the height of the base flood which would be attributable to any proposed uses.

[6] A deed notation or lease notation, to be placed on record to run with the land, which notation shall contain the following provision: "This lot is entirely (partially) within a floodplain district, as defined by ~ 287-7 of the Downingtown Borough Zoning Ordinance."

(h) In considering any application for a special exception or variance, the Zoning Hearing Board may request at the hearing the testimony of any Borough Board, Commission or technical advisor concerning the extent to which the proposed use would diminish the capacity of the Floodplain District to store and absorb floodwaters, to moderate flood velocities and to accommodate sediment; be subject to flood damage; cause erosion and impair the amenity of the Floodplain District; or adversely affect the area contiguous to the Floodplain District, as well as areas downstream, or on any other pertinent aspect of the case.

(i) In all proceedings before the Zoning Hearing Board, including application for special exception from the provisions of this section, the burden of proof shall be on the applicant to show that the use required will be in general conformity with the objectives of this section, that proper safeguards will be observed and that the use will not be injurious to the public health, safety and general welfare.

~ 287-13. Steep Slope Conservation District.

A. Intended purposes. The purposes of this section are as follows:

(1) To promote the public health, safety and welfare by the protection of steep slope areas and by encouraging the retention of open space located and designed so as to constitute a harmonious and appropriate part of the physical development of Downingtown Borough.

(2) To permit only those uses of steep slope areas which are compatible with the conservation of natural conditions and which maintain stable soil conditions by minimizing disturbances to vegetative ground covers and restricting the regrading of steep slope areas.

(3) To limit soil erosion and the resultant destruction of the land, siltation of streams and damage to the property of individuals.

(4) To protect low-lying areas from flooding by limiting the increase in stormwater runoff caused by grading of sloped areas, changes of ground cover or the erection of structures.

B. General provisions.

(1) Compliance. No area within the Steep Slope Conservation District shall hereafter be used without full compliance with the terms of this section and other applicable regulations.

(2) Steep Slope Conservation District overlay concept. The Steep Slope Conservation District shall be deemed an overlay on any zoning district(s) now or hereafter enacted to regulate the use of land in the Borough of Downingtown.

(a) The Steep Slope Conservation District shall have no effect on the permitted uses in the underlying zoning district, except where said uses are intended to be located within the boundaries of the Steep Slope Conservation District, as defined herein, and where said uses are in conflict with the permitted uses set forth in this section.

(b) In those areas of the borough where the Steep Slope Conservation District applies, the requirements of the Steep Slope Conservation District shall supersede the requirements of the underlying zoning district(s).

(c) Should the Steep Slope Conservation District boundaries be changed as a result of legislative or administrative actions or judicial decision, the zoning requirements applicable to the area in question shall revert to the requirements of the underlying zoning district(s) without consideration of this section.

(d) For any parcel or any part thereof on which the Steep Slope Conservation District is an overlay, should the underlying zoning classification(s) be changed as a result of legislative or administrative actions or judicial decision, such change(s) in classification shall have no effect on the boundaries of the Steep Slope Conservation District, unless an amendment to said boundaries was included as part of the proceedings from which the subsequent change(s) originated.

(3) Preservation of other restrictions. It is not intended by this section to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this section imposes greater restrictions, the provisions of this section shall prevail.

(4) Municipal liability. Any determination that a proposed use complies with this chapter or any approval of a subdivision or land development plan or any issuance of a building permit within or near the Steep Slope Conservation District shall not constitute a representation, guaranty or warranty of any kind by the borough or by any official or employee thereof of the practicability or safety of the proposed use and shall create no liability upon the borough, its officials or employees. This chapter does not imply that areas outside the Steep Slope Conservation District boundaries or land uses permitted within said district will always be totally free from the adverse effects of erosion or from other effects of nearby steep slopes.

C. Designation of district boundary. The Steep Slope Conservation District consists of any area which is delineated and defined as a slope of 20% or greater on the United States Geological Survey Topographic Map of the Regional Base Map Series of 1975 for the Downingtown Quadrangle (i.e., sloping 20 feet vertical over a distance of 100 feet horizontal), where such slope exists in any continuous horizontal increment of 50 feet or more.

D. Boundary interpretation and appeals procedure.

(1) Each application for construction or land disturbance within the Steep Slope Conservation District shall be submitted in accordance with Subsection F(1) below. Any area of the Steep Slope Conservation District that falls within the subject lot or lots shall be interpolated and shown on the site plan required under Subsection F(1)(a) through shading of such area or areas. The site plan shall contain a certification by the registered professional engineer or surveyor having prepared the plan as to the accuracy of the slopes as depicted on the plan. Areas shown as less than ten-percent slope may be based on United States Geological Survey information. Any area shown as ten-percent or greater slope shall be delineated on the basis of an actual field survey of the topography of the site.

(2) Where the exact location of the boundaries of the District in relation to a given parcel is in question, the applicant's site plan may be supplemented by a topographic survey of the property and any other documentation deemed pertinent. The Borough Engineer shall evaluate all such material submitted and shall make a written report of the results of his determination, a copy of which shall be provided to the Borough Council.

(3) Any party aggrieved by any such determination of the Borough Engineer or other decision or determination under this section may appeal to the Zoning Hearing Board. The party contesting the location of the district boundary shall have the burden of proof in case of any such appeal.

E. Permitted uses.

(1) Standards applicable to all uses within the Steep Slope Conservation District.

(a) All grading shall be minimized, and no grading shall be undertaken within any area of the Steep Slope Conservation District except where approved in conjunction with a use permitted under the terms of this section.

(b) Finished slopes of all cuts and fills shall not exceed 33%, unless the applicant can demonstrate that steeper slopes can be stabilized and maintained adequately.

(2) Uses permitted as of right. The following are the only uses permitted as of right within the Steep Slope Conservation District. Such uses also shall be in compliance with the base zoning district and all other applicable provisions of this chapter.

(a) Parks and outdoor recreational uses.

(b) Grading for the minimum portion of a driveway necessary to access a single-family dwelling, when it can be demonstrated that no other routing which avoids slopes exceeding 20% is feasible.

(d) Accessory uses (except swimming pools) necessary for the operation and maintenance of the above permitted uses.

(3) Uses permitted by special exception. Any of the following uses shall be permitted within the Steep Slope Conservation District as a special exception when authorized by the Zoning Hearing Board, subject to the requirements of this section and ~ 287-145 of this chapter.

(a) Single-family detached dwellings, if permitted in the underlying zoning district.

(b) Any road necessary to provide primary access to a use permitted by this chapter, when no practical alternative exists in an area of lesser slope. Any such road shall be constructed according to the standards of the Borough Subdivision and Land Development Ordinance.

(d) Sanitary or storm sewers, where approved by all regulatory agencies.

(4) On any lot containing an area or areas within the Steep Slope Conservation District, the total amount of impervious surface that may be installed or maintained within the total area or areas of the Steep Slope Conservation District shall not exceed 50% of the maximum amount of impervious surface permitted for such use on any lot in the underlying base zoning district. Provision shall be made, and approved by the Borough Engineer, for control of runoff from impervious surfaces to prevent erosion.

F. Administration. Administration of this section is governed by Article XXI of this chapter. In addition, the following requirements shall apply:

(1) Application procedures. Before a permit is issued for any construction or land disturbance activity on land within or affecting the Steep Slope Conservation District, the following material, in full or in pertinent parts, shall be submitted for review by the Borough Engineer:

(a) An earth-moving plan of the property which indicates existing grades, with contour lines at two-foot intervals where the existing slope is less than 10% and at five-foot intervals where the existing slope is 10% or greater. Proposed grades within the area of any proposed activity, disturbance or construction also shall be shown. All areas within the Steep Slope Conservation District shall be shaded accordingly.

(b) A site plan indicating existing and proposed structures, other impervious surfaces, storm drainage facilities and retaining walls. The site plan also shall locate and identify existing vegetation and ground cover within areas of the Steep Slope Conservation District, as well as proposed landscaping material to be installed.

(d) A statement, signed and sealed by a registered professional engineer or architect, explaining the building methods to be used in overcoming foundation and other structural problems created by slope conditions, in preserving the natural watershed conditions and in preventing soil erosion and excessive surface water runoff to neighboring properties and/or streets.

(e) An erosion and sedimentation control and drainage plan, prepared by a registered professional engineer, as it applies to all site disturbance activities, including maintenance of the erosion and sedimentation control structures. The drainage plan shall show all drainage features and structures, with supporting calculations documenting how all on-site stormwater runoff will be retained, conveyed and discharged.

(f) A plan, profile and typical cross sections of any proposed street, emergency access or driveway, with the seal of a registered professional engineer thereon.

(g) A statement, signed by the owner or future occupant at the time of subdivision, land development or building permit application, that there is a full understanding of any difficulties associated with access stemming from steep slopes.

(2) No approval or building permit shall be authorized by the Zoning Officer and no special exception shall be granted by the Zoning Hearing Board without the Borough Engineer's review of this material and his recommendation thereon.

~ 287-14. Soils with seasonally high water tables; wetlands.

A. Soils with seasonally high water table. No structure shall be constructed or located on or within any soil area where the seasonally high water table, according to the soil survey of Chester and Delaware Counties (Soil Conservation Service, 1963), is within one foot of the ground surface, provided that, for purposes for this section, Linside silt loam shall be considered to have a seasonal high water table in excess of one foot of the ground surface and shall not be considered soil with a seasonally high water table. The borough may, at its sole discretion, direct that a specific on-site investigation by a qualified soil scientist or engineer be conducted to verify the existence or nonexistence of soils with seasonably high water tables. This testing may be required when either the borough or the developer questions the suitability of the soils. [Amended 11-11-1992 by Ord. No. 92-8]

B. Wetlands.

(1) Wetlands shall be determined to exist when indicated by one or more of the following:

(a) The National Wetlands Inventory Maps, as prepared by the United States Fish and Wildlife Service.

(b) Hydric soils, as depicted in the Soil Survey of Chester and Delaware Counties.

(2) Should the existence of wetlands be indicated as per the requirements of Subsection B(1) above, a wetlands delineation shall be performed by a licensed professional engineer, hydrogeologist, soil scientist or similarly qualified professional experienced in wetlands ecology; the selection of this party shall be at the discretion of the applicant. Plans shall be submitted to the borough for review which show the delineation and indicate any disturbance of wetlands anticipated. The qualifications of the consultant performing the delineation shall be submitted with such plans. Further, unless it is clearly evident in such plans that no disturbance to the designated wetlands is anticipated, the delineation performed shall be submitted to the appropriate regulatory agencies, including but not limited to the Army Corps of Engineers and the Pennsylvania Department of Environmental Resources, for boundary confirmation and/or requisite wetlands permits. All potential impacts on wetlands shall conform to applicable regulations, as amended.

(3) Should the borough conclude, per the requirements of Subsection B(1), that wetlands exist on the site, contrary to the applicant's findings, the borough shall, at its discretion, request that either the Corps of Engineers or the Pennsylvania Department of Environmental Resources verify the borough's findings and perform a delineation. In the event that such agencies verify the borough's findings, the applicant will be required to secure any required wetlands permits, unless the applicant's activity clearly will not impact existing wetlands.

(4) Where wetlands exist and disturbance permits and/or mitigation activities are required, final plan approval or granting of applicable permits from the borough shall be contingent upon the applicant's receiving all necessary wetlands permits.

~ 287-15. Protection of existing vegetation.

A. Conservation of woodlands and other vegetation.

(1) During any land disturbance or site preparation work undertaken in conjunction with an approved subdivision or land development, disturbance to any healthy wooded area or any other significant vegetation shall be minimized. Particular attention shall be directed toward the protection of specimen trees.

(2) Disturbance or removal of vegetation occupying environmentally sensitive areas shall be undertaken only when necessary and on a limited, selective basis to minimize the adverse impacts of such actions. This shall include but not necessarily be limited to vegetation performing important soil-stabilizing functions on floodplains, stream- and pond banks and sloping lands.

B. Protection of vegetation from mechanical injury.

(1) All woody vegetation to be retained within 25 feet of a building site, parking area or other proposed improvement shall be protected from equipment damage by snow fencing or other effective barriers.

(2) Heavy-equipment operators shall minimize damage to existing tree trunks and root systems. Roots shall not be cut or disturbed within the area circumscribed by the dripline of any tree.

(3) Tree trunks and exposed roots damaged during construction shall be protected from further damage by fencing or other structural barrier. Treatment of damaged areas shall be dictated by the nature of the injury, e.g., damaged bark shall be cut back to a point where the bark is intact and tight to the tree, and exposed roots shall be cleaned up and covered with topsoil.

(4) Trees shall not be used for roping, cables, signs or fencing. Nails and spikes shall not be driven into trees.

(5) The area around the base of existing woody vegetation shall be left open. No impervious cover, storage of equipment, materials, debris or fill shall be allowed within the dripline of any existing tree.

C. Protection of vegetation from grading change. Grade changes to occur at any location on the property shall not result in an alteration to soil or drainage conditions which would adversely affect existing vegetation to be retained following site disturbance, unless adequate provisions are made to protect such vegetation and its root systems.

D. Protection of vegetation from excavations.

(1) When digging trenches for utility lines or similar uses, disturbance to the root zones of all woody vegetation shall be minimized.

(2) If trenches must be excavated in the root zone, all disturbed roots shall be cut as cleanly as possible. The trench shall be backfilled as quickly as possible, avoiding soil compaction.

~ 287-16. Excavation of clay, sand, gravel or rock.

The following shall apply to all districts:

A. The excavation of clay, sand, gravel, rock or other such material shall be permitted and the material thus excavated may be sold only under the following conditions: as part of the construction of a building or the construction or alteration of a street.

B. The surface of the lot shall not be graded to a level below that of the adjoining properties.

C. Excavation shall not be conducted in a way that will leave loose boulders exposed.

~ 287-17. Protection of topsoil.

A. No topsoil shall be removed from a site unless a sufficient amount is retained to provide at least four inches of topsoil cover over all of the site's exposed earth surfaces. More than four inches may be required if the borough determines that a greater amount is needed for the long-term viability of certain plantings.

B. Topsoil removed by grading operations shall be redistributed and stabilized as quickly as possible following the completion of a project phase. All exposed earth surfaces shall be stabilized by the following methods or an approved equivalent:

(1) Seeding or planting on slopes less than 10%.

(2) Sodding, hydroseeding or riprap on slopes exceeding 10%.

(3) Grading and earthmoving operations shall be scheduled to minimize site disturbance during the period from November 15 to April 1, when revegetation of exposed ground surfaces is difficult.

HOME | SITE MAP | SEARCH | TOP