Downingtown City Zoning Code
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.
[Amended 11-6-1996 by Ord. No. 96-16; 4-3-2002 by Ord. No. 2002-7; 11-15-2006 by Ord. No. 2006-06; 9-6-2017 by Ord. No. 2017-05]
The establishment and administration of the Floodplain District shall be governed by the provisions of Chapter 150, Floodplain Management, which are incorporated by reference as if set forth fully herein, as may be amended from time to time in accordance with the procedures set forth in Article XXI of this chapter and the Municipalities Planning Code.[1]
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
§ 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.
(c)
Access roads for the passage of emergency vehicles.
(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.[1]
(c)
Sealed public water supply wells, where approved by all regulatory agencies.
(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 earthmoving 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.
(c)
Architectural plans, elevations and sections.
(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:
(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, hydro-seeding 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.