Storm drainage facilities shall be designed to convey the flow of storm water runoff in a safe and efficient manner. The system shall ensure proper drainage along streets and provide positive drainage away from structures. The borough may require a primarily underground system to accommodate frequent floods and a secondary system to accommodate larger, less frequent floods. Drainage plans shall be consistent with local and regional drainage plans. The facilities shall be designed to prevent the excess runoff onto adjacent properties.
(A) Lots shall be laid out and graded to provide positive drainage away from buildings. The Borough Council may require a grading and drainage plan for individual lots indicating a buildable area within each lot, complying with the setback requirements, for which positive drainage is assured.
(B) No person, corporation, or other entity shall block, impede the flow of, alter, construct any structure or deposit any material or thing, or commit any act, which will affect normal or flood flow in any communal stream or watercourse without having obtained prior approval from the borough or Department of Environmental Protection, whichever is applicable.
(C) Where a subdivision or land development is traversed by a natural watercourse, there shall be provided a drainage easement or right-of-way conforming substantially with the line of such watercourse and of such width as will be adequate to preserve natural drainage.
(D) The borough will assure that all permanent streams, not under the jurisdiction of other official agencies, are maintained open and free flowing.
(E) The subdivider or developer and each person, corporation, or other entity which makes any surface changes shall be required to:
(1) Collect onsite surface runoff and dispose of it to the point of discharge into the common natural watercourse of the drainage area;
(2) Design drainage facilities to handle runoff from upstream areas, assuming full development of those areas, based upon the Comprehensive Plan for borough; and
(3) Design, construct, and/or install such drainage structures and facilities as are necessary to prevent erosion damage to the subdivision or land development, adjacent property, and downstream property. Such structures and facilities shall satisfactorily convey such surface waters to the nearest practical street, storm drain, detention pond, or natural watercourse.
(F) Storm sewers, culverts, and related installations shall be provided to permit unimpeded flow of natural watercourses, to drain all low points along streets, and to intercept storm water runoff along streets at intervals reasonably related to the extent and grade of the area drained.
(G) Storm sewers, as required, shall be placed in front of the curb or curb line when located in a street right-of-way. When located in undedicated land, they shall be placed within an easement not less than 15 feet wide, as approved by the Borough Engineer, who may require additional width of easement as circumstances warrant.
(H) Street drainage will not be permitted to cross intersections or the crown of the road.
(1) Maximum spacing of street inlets shall not exceed 600 feet.
(2) All street inlets shall be PennDOT Type C or M. Inlet tops shall be cast in place reinforced concrete or precast concrete.
(3) All culvert ends shall be provided with either reinforced concrete head walls or pipe end sections.
(4) Minimum pipe size shall be 15-inch diameter.
(5) When material for storm drain systems is not specified, PennDOT specifications will govern.
(I) All springs and sump pump discharges shall be collected so as not to flow in the streets.
(J) Storm water roof drains shall not discharge water directly over a sidewalk.
(K) Stabilized outlets shall be provided for footer drains, floor drains, and downspouts.
(L) The Soils Cover Complex Method of the Soil Conservation Service of the U.S. Department of Agriculture shall be used as the primary means of estimating storm water runoff.
(M) The Rational Method may be used for analysis of storm sewer systems and for storm water management facilities in minor subdivisions.
(N) Where the estimated runoff based upon the above methods is doubtful, several recognized methods should be studied and compared.
(O) The minimum design criteria shall be a ten-year storm. Higher frequency conditions shall be used in sensitive areas and where an overflow would endanger public or private property.
(P) Runoff calculations must include complete hydrologic and hydraulic design and analysis of all control facilities.
(Q) Control facilities.
(1) Permanent control measures/facilities shall be designed to assure that the maximum rate of storm water runoff is not greater after development than prior to development for a ten-year storm frequency. More stringent criteria may be required in sensitive areas where storm water problems presently exist.
(2) Control facilities shall be designed to meet, as a minimum, the design standards and specifications as determined by the Borough Engineer and approved by Borough Council.
(a) Detention ponds may be waived by the Borough Council on the recommendation of the Borough Engineer at sites in close proximity to major streams. This is to facilitate drainage prior to stream flooding.
(b) In areas underlain with limestone geology, ponds shall be limited to the detention (dry) type unless the developer can show a special need for a retention pond, in which case it shall have a lining. Detention ponds shall be prohibited in areas of known sinkholes unless the pond is lined. If a sinkhole develops in a pond or channel before acceptance by the borough, a lining shall be required.
(c) Any ponds with slopes steeper than three to one shall be fenced with a six-foot fence of a type subject to the approval of the borough.
(3) A maintenance program for control facilities must be included as part of the grading and drainage plan.
(a) Maintenance during development activities of a project shall be the responsibility of the contractor, developer, and owner.
(b) Arrangement for maintenance of permanent control facilities after completion of development activities shall be made before approval of final plans is given by the Borough Council.
(R) In cases where permanent control facilities are owned by an entity, it shall be the responsibility of that entity to maintain control facilities (e.g., homeowner’s association). In such cases, a legally binding agreement between the owner and the borough shall be made providing for maintenance of all permanent erosion control facilities, including the inspection by the borough.
(Prior Code, Ch. 22, Pt. 5, § 506) (Ord. 2-2001, passed 7-2-2001)