1. The floodplain areas of Thornbury Township are subject to periodic inundation which has resulted in the loss of property, damage to structures, disruption of public and private activities and services, burdensome public expenditures for flood protection and relief, and impairment of the tax base and may result in loss of life, all of which adversely affect the public health, safety, and welfare.
2. The general causes of these flood losses are the cumulative effect of impervious cover and obstructions in the floodplain causing increases in flood heights and velocities, and the occupancy of floodplains by uses vulnerable to floods.
(Ord. 2-1976, 2/3/1976, §1301; as amended by Ord. 2-2009, 11/18/2009, §II)
It is the purpose of this Article to promote to the public health, safety and general welfare and to minimize those losses described in §27-1502.1 by provisions designed to:
A. Restrict or prohibit uses which are dangerous to health, safety or property in times of flood and/or cause increase flood height or velocities.
B. Protect the quality and quantity of surface and subsurface water supplied adjacent to and/or underlying the floodplain.
C. Provide areas for the deposition of flood-borne sediment.
D. Require that all uses vulnerable to floods (including public facilities) where they are permitted by special exception or variance, be so constructed as to be protected against flood damage.
E. Require that, where uses are permitted by special exception or variance, written notice be given to prospective purchasers and/or lessees that the land under consideration for agreement of sale or lease is designated as lying either partially or totally within the floodplain as it is defined by §27-1504 of this Article and/or the Township Zoning Map.
F. Require that, whenever there is a transfer of the ownership of land which lies either totally or partially within the floodplain as it is defined by this Article and/or the Township Zoning Map, the deed effectuating such transfer shall contain appropriate notation.
G. Protect the natural drainage ways in order to provide areas for flood water transport with the least possible perturbation to life and property.
H. Comply with the minimum requirements of the National Flood Insurance Program and the Pennsylvania Flood Plain Management Act (1978-166).
(Ord. 2-1976, 2/3/1976, §1302; as amended by Ord. 2-2009, 11/18/2009, §II)
1. The Floodplain Conservation District is defined and established to be the low areas adjoining and including a watercourse or other body of water (such as "pond, marsh and/or lake") which are subject to the 100-year flood level, as delineated in the Flood Insurance Study on the Flood Insurance Rate Map (FIRM) for Delaware County, Pennsylvania, prepared by the Federal Emergency Management Agency effective November 18, 2009, and as mostly alluvial soils are delineated in the Soil Survey for Chester and Delaware Counties, Pennsylvania, 1964, prepared by the United States Department of Agriculture, Soil Conservation Service. It includes the areas defined-as "alluvial soils" (§27-1501), "floodway," (§27-1501), "floodway fringe" (§27-1501) and "approximated floodplain" (§27-1501).
2. The area designated floodplain in Thornbury Township is outlined and delineated using hydrologic technical data compiled by the Federal Emergency Management Agency, Flood Insurance Study for Delaware County, Pennsylvania, effective November 18, 2009, which includes the 100-year frequency flood data plus projected runoff data from future development per applicable comprehensive plans; and, soil data compiled by the United States Department of Agriculture, Natural Resources Conservation Service.
3. The Floodplain Conservation District shall be shown on the Thornbury Township Zoning Map which, together with a specific Floodplain District Map and all explanatory material, shall be available for inspection upon request to the Township Secretary.
4. For purposes of defining application of this Article and its map to any specific area, the Township Zoning Map, data and other sources of material specified in subsections .2 and .3 of this Section shall be available and shall be proof of the intended limits of the Floodplain Conservation District. No reduction in the Floodplain Conservation District shall be made without prior consultation with and approval of the Federal Insurance Administrator. Any changes which are officially adopted shall be recorded on the Township Zoning Map.
A. In the case of any dispute concerning the boundaries of the Floodplain Conservation District, an initial determination shall be made by the Township Engineer and a report, in writing, made to the Board of Supervisors.
B. Any party aggrieved by any determination of the Township Engineer which has been approved by the Board of Supervisors as to the boundaries of the Floodplain Conservation District or other decision or determination under this Article may appeal to the Zoning Hearing Board. The burden of proof of such appeal shall be on the applicant.
(Ord. 2-1976, 2/3/1976, §1303; as amended by Ord. 9/7/1977; by Ord. 1-1994, 4/5/1994, §2; and by Ord. 2-2009, 11/18/2009, §II)
The following uses and no others (unless by special exception or variance granted by the Zoning Hearing Board) are permitted in the Floodplain Conservation District; provided, that if located in the floodway, no new construction, development, use, activity or encroachment would result in any increase in flood heights:
A. Cultivation and harvesting of crops in accordance with recognized soil conservation practices, as defined and determined by the U.S. Department of Agriculture, Natural Resources Conservation Service.
B. Pasture and grazing.
C. Outdoor plant nursery, orchard, tree farm.
D. Fish hatchery, hunting and fishing preserve.
E. Wildlife sanctuary.
F. Permeable parking areas and driveways when permitted by the regulations for the contiguous zoning district otherwise applicable to the lot.
G. Closed sanitary sewer line systems, designed and constructed to minimize or eliminate infiltration, when constructed on the floodway fringe of the Floodplain Conservation District, but in no case running along or directly within the floodway, except when such required course must cross a floodway junction.
H. A maximum of three-quarters of any setback required for the development of any lot or tract in any zoning district contiguous to the Floodplain Conservation District; provided, that such setback shall not be used for any on-site sewage disposal system or a well.
(Ord. 2-1976, 2/3/1976, §1304; as amended by Ord. 1-1994, 4/5/1994, §2; and by Ord. 2- 2009, 11/18/2009, §II)
1. The following uses may be allowed when granted by the Zoning Hearing Board:
A. Sewage treatment plants and pumping stations, water pumping station and water treatment plants, and storm sewer systems, subject to approval of the Department of Environmental Protection of the Commonwealth and the Township Engineer, when constructed on the floodway fringe of the Floodplain Conservation District, but in no case within the floodway. These systems shall be designed and constructed to eliminate infiltration of floodwaters into the systems and discharges from the systems into the waters of the Commonwealth.
B. Dams, culverts, and bridges when approved by the Department of Environmental Protection of the Commonwealth and the Township Engineer.
C. Recreational uses, both public and private, such as parks, day camps, athletic fields, excluding permanent structures.
D. Grading and/or fill provided that the effect does not adversely affect either the cross-sectional profile of the stream, watercourse and Floodplain Conservation District, or increase the 100-year flood level of the floodway or the velocity of the water in the floodway at the point of such grading or fill. All requests for change of grade shall be accompanied by a detailed engineering report, including maps showing all existing contours and all proposed contours. In no case shall fill be used which should in any way contaminate or pollute the stream; pond, lake or other water body.
2. Factors to be considered by the Zoning Hearing Board in passing upon each application for a special exception are as follows:
A. The danger to life and property due to increased flood levels or velocities caused by encroachments.
B. The danger that materials may be swept on to other lands or downstream to the possible injury of others.
C. The ability of any proposed water supply and/or sanitation systems to avoid causing disease, contamination, and unsanitary conditions.
D. The susceptibility of the proposed use to flood damage and the effect of such damage on the owner and the community.
E. The requirements of the use for a floodway or floodway fringe location.
F. The availability of alternative locations, not subject to flooding, for the proposed use.
G. The compatibility of the proposed use with existing and foreseeable nearby uses.
H. The relationship of the proposed use to the Comprehensive Plan and floodplain conservation management program for the area.
I. The safety of access to the property in times of flood for ordinary and emergency vehicles.
J. The expected levels, velocity, duration, rate of rise, and sediment transport of the flood waters in the Floodplain Conservation District, expected at the site resulting from a study by a registered professional engineer qualified in hydrology in the Commonwealth.
K. Such other factors which may be considered relevant to the purposes of this Article.
(Ord. 2-1976, 2/3/1976, §1305; as amended by Ord. 2-2005, 7/6/2005; and by Ord. 2-2009, 11/18/2009, §II)
1. Hardship. Except where specifically prohibited in this Article, if compliance with the requirements of this Article would result in exceptional hardship to a prospective builder, developer, or landowner, the Zoning Hearing Board may, upon request, grant relief from the strict application of the requirements of this Article in accordance with this Section.
2. Standards. In any instance where the Zoning Hearing Board is required to consider a request for a variance from the provisions of this Article, the Board shall first determine that the standards and criteria enumerated in §910.2 of the Municipalities Planning Code, 53 P.S. §10910.2, are met before granting the request. The Board shall not grant any use variance for uses listed under §27-1511 of this Article.
3. In considering whether the proposed use would be injurious to the public health, welfare and safety, the Board shall give special and particular consideration to the following factors:
A. The danger to life and property due to increased flood levels or velocities caused by encroachments.
B. The danger that materials may be swept on to other lands or downstream to the possible injury of others.
C. The ability of any proposed water supply and/or sanitation systems to avoid the causing of disease, contamination and unsanitary conditions.
D. The susceptibility of the proposed use to flood damage and the effect of such damage on the owner or occupant and the community.
4. Notice shall be given to the Federal Emergency Management Agency and the Pennsylvania Department of Economic and Community Development of all variances granted under this Article.
5. Whenever a variance is granted under this Article, the applicant shall be notified in writing that:
A. The granting of the variance may result in increased premium rates for flood insurance.
B. Such variances may increase risks to life and property.
(Ord. 2-1976, 2/3/1976, §1306; as amended by Ord. 1-1994, 4/5/1994, §2; and by Ord. 2-2009, 11/18/2009, §II)
1. Upon consideration of the purposes of this Article, the Board may attach such conditions to the granting of a special exception or variance as it deems necessary to further the purposes of this Article including, without limitation, because of specific enumeration, the following:
A. Any new construction and/or substantial improvement to an existing structure shall have the lowest floor including basement elevated to one and one- half feet above the surface water elevation for a 100-year flood at the place of construction. In any area for which the said elevation is not designated in the Flood Insurance Study or Flood Insurance Rate Map for the Township, the required elevation shall be determined by selecting the point on the boundary of the approximated floodplain nearest to the site in question and elevating the lowest floor of the structure to one and one-half feet above such elevation. All such structures shall be securely anchored to prevent flotation, collapse and lateral movement; all such structures shall employ construction materials and techniques to minimize flood damage. Adequate drainage shall be provided. The elevation of the proposed lowest floor shall be indicated on the application for a building permit. The provisions of all other State and Federal rules and regulations are applicable to such construction including the provisions of §60.3(d) of the National Flood Insurance Program Regulations.
B. That such uses shall be designed so that the floodway shall carry the waters of the 100-year flood without increasing the water surface elevation of that flood at any point.
2. In any case where the Board shall grant a special exception to permit the erection of a building in the floodplain "floodway fringe" or "approximated floodplain" and the premises with such a modified use should be offered for sale or lease, or shall grant a variance or special exception to permit a change in a nonconforming use of a building already existing in a Floodplain Conservation District and such use could be offered for sale or lease, the Board shall, for the protection of prospective purchasers and lessees, impose the following conditions:
A. Require the applicant to advise prospective purchasers and/or lessees in writing that the lot is located in its entirety or partially, as the case may be, in the Floodplain Conservation District and to place such notation on any agreement of sale or lease.
B. Require that, before settlement or change in use, as the case may be, the purchaser or lessee shall signify in writing that he has been advised that the premises lies entirely or partially in the Floodplain Conservation District and a signed copy of such signification shall be delivered to the Township Secretary.
C. Where the premises are to be conveyed, require that the deed shall contain the following notation: "This lot is entirely (partially) within the Floodplain Conservation District as defined by Article 15 of the Zoning Ordinance of Thornbury Township, Delaware County, Pennsylvania."
(Ord. 2-1976, 2/3/1976, §1307; as amended by Ord. 91711977; by Ord. 1-1994, 4/5/1994, §2; and by Ord. 2-2009, 11/18/2009, §II)
1. Procedure. Upon receiving an application for a special exception or a variance, the Zoning Hearing Board shall, prior to hearing, require the applicant to furnish such of the following materials as is deemed necessary by the Board under the existing use conditions and as it would exist if the proposed use were approved, as appropriate.
A. Five copies of plans drawn to scale showing the nature, location, dimensions and elevation of the lot; photographs showing existing uses and vegetation; soil types and other pertinent information.
B. A series of cross-sections at 20-foot intervals along the lot shoreline, showing the stream channel, or the lake or pond bottom, and elevation of adjoining land areas to be occupied by the proposed uses, and high water information.
C. Profile showing the existing slope of the bottom of the channel, lake or pond and calculations as to the effect of the proposed use upon the bottom and banks of the channel, lake or pond.
D. Specifications for building materials and construction, flood proofing, filling, dredging, grading, storage, water supply, and sanitary facilities.
E. Computation of the change, if any, in the level and velocity of the water which would be attributable to any proposed uses.
F. Specific elevations of the lowest point of the nearest building line to the floodplain boundary and point at which the building leaves the Floodplain Conservation District.
2. In considering any application for a special exception or variance, the Zoning Hearing Board may request before the hearing, the written advice of the Board of Supervisors, the Planning Commissions, the Township Engineer and other technical experts, concerning the extent to which the proposed use would:
A. Diminish the capacity of the Floodplain Conservation District to store and absorb flood waters, to increase flood velocities, and to accommodate sediment.
B. Be subject to flood damage.
C. Cause erosion and impair the amenity of the Floodplain Conservation District.
D. Adversely affect the area contiguous to the Floodplain Conservation District as well as the areas downstream.
3. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
4. The Township shall notify the applicant in writing over the signature of a Township official that (A) the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance and (B) such construction below the base flood level increases risks to life and property. Such notification shall be maintained with a record of all variance actions.
5. The Township shall (A) maintain a record of all variance actions, including justification for their issuance, and (B) report such variances issued in its annual or biennial report submitted to the Federal Insurance Administrator.
(Ord. 2-1976, 2/3/1976, §1308; as amended by Ord. 91711977; by Ord. 1-1994, 4/5/1994, §2; and by Ord. 2-2009, 11/18/2009, §II)
Whenever there is a transfer of ownership of land which lies either totally or partially in the floodplain as it is defined by §27-1504 of this Article andor the Township Zoning Map, the deed effectuating such transfer shall contain the following information:
"This lot is entirely (partially) within the Floodplain Conservation District as defined by Article 15 of the Zoning Ordinance of Thornbury Township, Delaware County, Pennsylvania."
(Ord. 2-1976, 2/3/1976, §1309; as amended by Ord. 2-2009, 11/18/2009, §II)
In addition to and without limitation of the uses specifically permitted in the Floodplain Conservation District by the provisions of §27-1505 of this Article, the following activities are specifically prohibited in the Floodplain Conservation District:
A. The clearing of vegetation except for brush, weeds and the removal of diseased shrubs or trees, or trees or portions thereof which might cause hazard to life or property; and except where such clearing is necessary for construction permitted as a result of action by the Zoning Hearing Board.
B. Sod farming.
C. Storage of any material which, if inundated, would float.
D. Storage of flammable or toxic material or any other material which, if inundated, would degrade or pollute the stream, or cause damage if swept downstream.
E. Installation or maintenance of on-site sewage disposal systems and wells.
F. Placement or maintenance of a manufactured home.
G. Alteration or relocation of any watercourse, unless and until the applicant has notified the governing bodies of adjacent municipalities and the Pennsylvania Department of Community and Economic Development, with copies of such notices being sent to the Flood Insurance Administrator, and demonstrated to the watercourse as altered or relocated is maintained at a level equal to or better than the existing flood carrying capacity. This requirement shall be in addition to the requirements of the Pennsylvania Department of Environmental Protection pertaining to such alteration or relocation.
H. The construction or use of any structure for the production or storage of any of the following materials or substances, or for any activity involving the depositing or maintenance of any of the following materials or substances on the premises (including both indoors and outdoors):
(1) Acetone
(2) Ammonia
(3) Benzene
(4) Calcium carbide
(5) Carbon disulfide
(6) Celluloid
(7) Chlorine
(8) Hydrochloric acid
(9) Hydrocyanic acid
(10) Magnesium
(11) Nitric acid and oxides of nitrogen
(12) Petroleum products (gasoline, fuel oil, etc.)
(13) Phosphorus
(14) Potassium
(15) Sodium
(16) Sulphur and sulphur products
(17) Pesticides (including insecticides, fungicides and rodenticides)
(18) Radioactive substances, insofar as such substances are not otherwise regulated.
I. The construction, enlargement or expansion of any structure used or intended to be used for hospitals, nursing homes and prisons.
(Ord. 2-1976, 2/3/1976, §1310; as amended by Ord. 9/7/1977; by Ord. 11-1982, 12/6/1982; by Ord. 1-1994, 4/5/1994, §2; by Ord. 2-2005, 7/6/2005; and by Ord. 2-2009, 11/18/2009, §II)
