Township of Derry, PA Article VII Stormwater Management

[Added 7-19-2004 by Ord. No. 2004-6]

§ 186-46 General provisions.

A. Statement of findings. The governing body of the Township of Derry, Mifflin County, Pennsylvania (hereinafter referred to as the "municipality"), finds that:

(1) Inadequate management of accelerated stormwater runoff resulting from development throughout a watershed increases flood flows and velocities, contributes to erosion and sedimentation, overtaxes the carrying capacity of existing streams and storm sewers, greatly increases the cost of public facilities to convey and manage stormwater, undermines floodplain management and flood reduction efforts in upstream and downstream communities, reduces groundwater recharge, and threatens public health and safety.

(2) A comprehensive program of stormwater management, including reasonable regulation of development and activities causing accelerated erosion, is fundamental to the public health, safety, welfare, and the protection of the people of the municipality and all the people of the commonwealth, their resources, and the environment.

B. Purpose. The purpose of this article is to promote health, safety, and welfare within the Kishacoquillas Creek Watershed by minimizing the damages described in Subsection A(1) of this section through provisions designed to:

(1) Manage accelerated runoff and erosion and sedimentation problems at their source by regulating activities that cause these problems.

(2) Utilize and preserve the existing natural drainage systems.

(3) Encourage recharge of groundwater where appropriate and prevent degradation of groundwater quality.

(4) Maintain existing flows and quality of streams and watercourses in the municipality and the commonwealth.

(5) Preserve and restore the flood-carrying capacity of streams.

(6) Provide proper maintenance of all permanent stormwater management facilities that are constructed in the municipality.

(7) Provide performance standards and design criteria for watershed-wide stormwater management and planning.

C. Statutory authority. The municipality is empowered to regulate land use activities that affect runoff by the authority of the Act of October 4, 1978, P.L. 864 (Act 167), (32 P.S. § 680.1 et seq. as amended), the Storm Water Management Act, the Second Class Township Code, Act of May 1, 1933, P.L. 103, No. 69, Section 101 et seq., as reenacted and amended (53 P.S. § 65601 et seq., as reenacted and amended) and the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, art. I, Section 101, as amended and reenacted (53 P.S. § 10101 et seq., as amended and reenacted).

D. Applicability.

(1) This article shall apply to those areas of the municipality that are located within the Kishacoquillas Creek Watershed, as delineated in Appendix D,[1] which is hereby adopted as part of this article.

[1] Editor's Note: Said appendix is on file in the Township offices.

(2) This article is intended to control stormwater-related quantity and quality during and after construction as part of any of the regulated activities listed in this section. Stormwater management and erosion and sedimentation control during construction activities shall be regulated by both this article and under existing laws and ordinances related to erosion and sediment control.

(3) This article contains only the stormwater management performance standards and design criteria that are necessary or desirable from a watershed-wide perspective. Local stormwater management design criteria (e.g., inlet spacing, inlet type, collection system design and details, outlet structure design, etc.) shall continue to be regulated by the applicable municipal ordinances or at the municipal engineer's discretion.

(4) The following activities are defined as "regulated activities" and shall be regulated by this article:

(a) Land development.

(b) Subdivision.

(c) Construction of new or additional impervious or semipervious surfaces (driveways, parking lots, etc.).

(d) Construction of new buildings or additions to existing buildings.

(e) Diversion or piping of any natural or man-made stream channel.

(f) Installation of stormwater management facilities or appurtenances thereto.

(g) Placement of fill material.

E. Exemptions.

(1) Any regulated activity that meets the following criteria shall not be required to implement the stormwater controls prescribed in § 186-48A, D and E of this article. These criteria shall apply to the total development even if development is to take place in phases. The date of the municipal ordinance adoption shall be the starting point from which to consider tracts as parent tracts in which future subdivisions and respective impervious area computations shall be cumulatively considered. Exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. Developers that seek relief under this exemption criteria are responsible for any damages to downstream properties caused by the failure to install sufficient controls to protect said properties from an increase in the volume or rate of runoff from the developed property and may be required to install additional controls at their own expense if damage to downstream property does occur.

	Stormwater Management Exemption Criteria
	Impervious Area Exemption
	•	Proposed impervious area must be less than 20% of total parcel area and less than 5,000 square feet.
	"Proposed impervious area" as used in the above exemption criteria is defined as the total impervious area added to the parcel since the adoption of this article.

(2) Requirements for exempted activities.

(a) Any regulated activity that meets the above stated criteria must satisfy water quality and groundwater recharge criteria. However, they can meet the criteria of § 186-48B and C of this article if it can be shown that all new impervious surfaces are disconnected from direct conveyance into curb/gutter, storm sewer, or open channel systems and said impervious surfaces are constructed to allow for the filtration, either naturally or mechanically, of runoff to address water quality concerns and potentially to improve infiltration. Examples include but are not limited to:

[1] Controlling runoff through a sheet flow system of vegetative or similar buffers having a minimum flow length equal to or greater than 25 feet, or the average width of impervious area, whichever is greater, and the square footage of the pervious area is equal to or greater than 50% of the new impervious area;

[2] Disconnecting roof downspouts from direct discharge to curb/gutter or storm sewer systems and allowing the downspout discharge to flow over plant, lawn or woodland areas in such a manner as to avoid rill or gully erosion;

[3] Passing concentrated runoff through grease and oil separators before discharge to storm sewers or open channels;

[4] Using infiltration basins or trenches to promote infiltration and filtration of runoff from impervious surfaces;

[5] Use of cisterns or French drains to promote infiltration of runoff from impervious areas; and

[6] Discharge of concentrated runoff to constructed wetlands that are designed to filter pollutants from the runoff.

(b) Other best management practice approaches (bioinfiltration swale, bioretention basin, etc.) can also be used. The Municipal Engineer shall have authority to review, approve, reject, or recommend alternative methods for meeting the requirements of § 186-48B and C.

(3) No exemption shall be provided for regulated activities as defined in Subsection D(4)(e) and (f) of this section.

§ 186-47 Definitions; word usage.

A. Word usage. For the purposes of this article, certain terms and words used herein shall be interpreted as follows:

(1) Words used in the present tense include the future tense; the singular number includes the plural, and the plural number includes the singular; words of masculine gender include feminine gender; and words of feminine gender include masculine gender.

(2) The word "includes" or "including" shall not limit the term to the specific example but is intended to extend its meaning to all other instances of like kind and character.

(3) The word "person" includes an individual, firm, association, organization, partnership, trust, company, corporation, or any other similar entity.

(4) The words "shall" and "must" are mandatory; the words "may" and "should" are permissive.

(5) The words "used or occupied" include the words "intended, designed, maintained, or arranged to be used, occupied or maintained."

B. Definitions. As used in this article, the following terms shall have the meanings indicated:

ACCELERATED EROSION

The removal of the surface of the land through the combined action of man's activity and the natural processes of a rate greater than would occur because of the natural process alone.

ACCESSORY STRUCTURE

A structure detached from a principal building located on the same lot and customarily incidental and subordinate to the principal building or use.

AGRICULTURAL ACTIVITIES

The work of producing crops and raising livestock, including tillage, plowing, disking, harrowing, pasturing and installation of conservation measures. Construction of new buildings or impervious area is not considered an agricultural activity.

ALTERATION

As applied to land, a change in topography as a result of the moving of soil and rock from one location or position to another; also the changing of surface conditions by causing the surface to be more or less impervious; land disturbance.

APPLICANT

A landowner or developer who has submitted a drainage plan or filed an application for approval to engage in any regulated activities as defined in § 186-46D of this article.

AS-BUILT DRAWINGS

A set of engineering or site drawings that delineate the specific permitted stormwater management facility as actually constructed.

BMP (BEST MANAGEMENT PRACTICE)

Stormwater structures, facilities and techniques to maintain or improve the water quality of surface runoff; Pennsylvania Handbook of Best Management Practices for Developing Areas, Spring, 1998.

BUFFER

See "stream buffer."

CHANNEL EROSION

The widening, deepening, and headward cutting of small channels and waterways, due to erosion caused by moderate to large floods.

CISTERN

An underground reservoir or tank for storing rainwater.

CONSERVATION DISTRICT

The Mifflin County Conservation District.

CULVERT

A structure with appurtenant works that carries a stream under or through an embankment or fill.

DAM

An artificial barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semifluid, or a refuse bank, fill or structure for highway, railroad or other purposes which does or may impound water or another fluid or semifluid.

DEED RESTRICTION

See "restrictive covenant."

DESIGN STORM

The magnitude and temporal distribution of precipitation from a storm event measured in probability of occurrence (e.g., a five-year storm) and duration (e.g., 24 hours), used in the design and evaluation of stormwater management systems.

DESIGNEE

The agent of the Mifflin County Planning Commission and/or agent of the municipality involved with the administration, review or enforcement of any provisions of this article by contract or memorandum of understanding.

DETENTION BASIN

An impoundment structure designed to manage stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate.

DETENTION DISTRICT

Those subareas in which some type of detention is required to meet the plan requirements and the goals of Act 167.

DEVELOPER

A person, partnership, association, corporation, or other entity, or any responsible person therein or agent thereof, that undertakes any regulated activity of this article.

DEVELOPMENT

See "land development."

DEVELOPMENT SITE

The specific tract of land for which a regulated activity is proposed.

DISCHARGE EASEMENT

The grant of a property right to allow runoff in excess of the previous quantity and/or rate of flow.

DOWNSLOPE PROPERTY LINE

That portion of the property line of the lot, tract, or parcels of land being developed located such that all overland or pipe flow from the site would be directed towards it.

DRAINAGE CONVEYANCE FACILITY

A stormwater management facility designed to transmit stormwater runoff and shall include streams, channels, swales, pipes, conduits, culverts, storm sewers, etc.

DRAINAGE EASEMENT

A right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes.

DRAINAGE PERMIT

A permit issued by the municipality after the drainage plan has been approved. Said permit is issued prior to or with the final Township approval.

DRAINAGE PLAN

The documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in § 186-49C.

EARTH DISTURBANCE

Any activity, including, but not limited to, construction, mining, timber harvesting and grubbing which alters, disturbs, and exposes the existing land surface.

EASEMENT

A right-of-way granted for limited use of private land for a public or quasi-public purpose (e.g., utility lines, discharge easement, drainage easement), and within which the owner of the property shall not erect any permanent structures.

EPHEMERAL STREAMS (also EPHEMERAL FLOW)

Streams that carry only surface runoff and are dry except during precipitation events. The groundwater table is generally located below the bottom of ephemeral streams.

EROSION

The movement of soil particles by the action of water, wind, ice, or other natural forces.

EROSION AND SEDIMENT POLLUTION CONTROL PLAN

A plan that is designed to minimize accelerated erosion and sedimentation. Said plan must be submitted to and approved by the Mifflin County Conservation District before construction can proceed.

EXISTING CONDITIONS

The initial condition of a project site prior to the proposed construction. If the initial condition of the site is undeveloped land, the land use shall be considered as "meadow" on "B" soils unless the natural land cover is proven to generate lower curve numbers or Rational "C" value, such as forested lands.

FLOOD

A general but temporary condition of partial or complete inundation of normally dry land areas from the overflow of streams, rivers, and other waters of this commonwealth.

FLOODPLAIN

Any land area susceptible to inundation by water from any natural source or delineated by applicable Department of Housing and Urban Development, Federal Insurance Administration flood hazard boundary, mapped as being a special flood hazard area. Also included are areas that comprise Group 13 Soils, as listed in Appendix A of the Pennsylvania Department of Environmental Protection (PADEP) Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by PADEP).

FLOODWAY

The channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the one-hundred-year frequency flood. Unless otherwise specified, the boundary of the floodway is as indicated on maps and flood insurance studies provided by FEMA. In an area where no FEMA maps or studies have defined the boundary of the one-hundred-year frequency floodway, it is assumed — absent evidence to the contrary — that the floodway extends from the stream to 50 feet from the top of the bank of the stream.

FOREST MANAGEMENT/TIMBER OPERATIONS

Planning and activities necessary for the management of forest land. These include timber inventory and preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation and reforestation.

FREEBOARD

A vertical distance between the elevation of the design high water and the top of a dam, levee, tank, basin, or diversion ridge. The space is required as a safety margin in a pond or basin.

GRADE

(1) A slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein.

(2) TO) GRADE  To finish the surface of a roadbed, top of embankment or bottom of excavation.

GRASSED WATERWAY

A natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to conduct surface water from cropland.

GROUNDWATER RECHARGE

Replenishment of existing natural underground water supplies.

IMPERVIOUS SURFACE

A surface that has been compacted or covered with material to the extent that it is highly resistant to infiltration by water, including, but not limited to, conventional impervious surfaces such as paved streets, roofs, compacted stone, and sidewalks. In addition, the following shall be considered impervious surfaces when used by motor vehicles: graveled areas, paver blocks, bricks, and cobblestone.

IMPOUNDMENT

A retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.

INFILTRATION STRUCTURES

A structure designed to direct runoff into the ground (e.g., french drains, seepage pits, seepage trench).

INLET

A surface connection to a closed drain. A structure at the diversion end of a conduit. The upstream end of any structure through which water may flow.

INTERMITTENT STREAMS (also INTERMITTENT FLOW)

Streams that flow only during wet seasons. The groundwater table generally is at or above the bottom of intermittent streams during wet seasons, but drops below the stream bottom during dry seasons. Stream flow in intermittent streams is primarily due to precipitation, but does have some groundwater contribution during wet seasons.

LAND DEVELOPMENT

As now defined or as may be defined in the Pennsylvania Municipalities Planning Code (MPC),[1] the term "land development" means any of the following activities:

(1) The improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving:

(a) A group of two or more residential or nonresidential buildings, whether proposed initially or cumulatively, or a single nonresidential building on a lot or lots regardless of the number of occupants or tenure; or

(b) The division or allocation of land or space, whether initially or cumulatively, between or among two or more existing or prospective occupants by means of, or for the purpose of streets, common areas, leaseholds, condominiums, building groups, or other features.

(2) Any subdivision of land.

(3) Development in accordance with Section 503(1.1) of the Pennsylvania Municipalities Planning Code.[2]

LAND/EARTH DISTURBANCE

Any activity involving grading, tilling, digging, or filling of ground or stripping of vegetation or any other activity that causes an alteration to the natural condition of the land.

MAIN STEM (MAIN CHANNEL)

Any stream segment or other runoff conveyance facility used as a reach in the Kishacoquillas Creek hydrologic model.

MANNING EQUATION (MANNING FORMULA)

A method for calculation of velocity of flow (e.g., feet per second) and flow rate (e.g., cubic feet per second) in open channels based upon channel shape, roughness, depth of flow and slope. "Open channels" may include closed conduits so long as the flow is not under pressure.

MUNICIPALITY

The Township of Derry, Mifflin County, Pennsylvania.

NONPOINT SOURCE POLLUTION

Pollution that enters a watery body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.

NPDES

National Pollutant Discharge Elimination System; a permit issued by the Pennsylvania Department of Environmental Protection regulating the discharge of wastewater or stormwater from a facility. NPDES permits are issued under the authority of the Clean Water Act (P.L. 92-500).[3]

NRCS

Natural Resource Conservation Service (previously SCS).

OPEN CHANNEL

A drainage element in which stormwater flows with an open surface. Open channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes flowing partly full.

OUTFALL

Point where water flows from a conduit, stream, or drain.

OUTLET

Points of water disposal from a stream, river, lake, tidewater or artificial drain.

PARKING LOT STORAGE

Involves the use of impervious parking areas as temporary impoundments with controlled release rates during rainstorms.

PEAK DISCHARGE

The maximum rate of stormwater runoff from a specific storm event.

PENN STATE RUNOFF MODEL (CALIBRATED)

A computer-based hydrologic modeling technique.

PERENNIAL STREAMS (also PERENNIAL FLOW)

Streams that flow year round. Perennial streams derive their flow from both groundwater and runoff and the groundwater table never drops below the streambed.

PIPE

A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.

PLANNING COMMISSION

The Mifflin County Planning Commission, unless otherwise specified.

PROBABLE MAXIMUM FLOOD (PMF)

The flood that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in any area. The PMF is derived from the probable maximum precipitation (PMP) as determined on the basis of data obtained from the National Oceanographic and Atmospheric Administration (NOAA).

RATIONAL FORMULA

A rainfall-runoff relation used to estimate peak flow.

REDEVELOPMENT

Reconstruction of an existing improved, developed property, as of the date of adoption of this article.

REGULATED ACTIVITIES

Actions or proposed actions that have an impact on stormwater runoff and that are specified in § 186-46D of this article.

RELEASE RATE

The percentage of predevelopment peak rate of runoff from a site or subarea to which the postdevelopment peak rate of runoff must be reduced to protect downstream areas.

RESTRICTIVE COVENANT

A restriction on the use of land usually set forth in the deed. Restrictive covenants (also known as "deed restrictions") usually run with the land and are binding upon subsequent owners of the property.

RETENTION BASIN

An impoundment in which stormwater is stored and not released. Stored water may be released from the basin at some time after the end of the storm (temporary retention), or else it leaves the basin through infiltration or evaporation.

RETURN PERIOD

The average interval, in years, within which a storm event of a given magnitude can be expected to recur. For example, the twenty-five-year return period rainfall would be expected to recur on the average once every 25 years.

RISER

A vertical pipe extending from the bottom of a pond that is used to control the discharge rate from the pond for a specified design storm.

ROOFTOP DETENTION

Temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.

RUNOFF

Any part of precipitation that flows over the land surface.

SEDIMENTATION

The process by which mineral or organic matter is accumulated or deposited by the movement of water.

SEDIMENT BASIN

A barrier, dam, retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water.

SEDIMENT POLLUTION

The placement, discharge or any other introduction of sediment into the waters of the commonwealth occurring from the failure to design, construct, implement or maintain control measures and control facilities in accordance with the requirements of this article.

SEEPAGE PIT/SEEPAGE TRENCH

An area of excavated earth filled with loose stone or similar coarse material, into which surface water is directed for infiltration into the ground.

SEMIPERVIOUS SURFACES

Material that allows rainfall to seep through to the underlying strata. Examples include gravel, porous asphalt pavement, and paving blocks not used for motor vehicles. If these materials are used for vehicular pathways, parking, and material storage, they are generally considered to be impervious. Use of these materials in development sites must be supported by published information concerning infiltration rates if credit is to be taken for the infiltration volume.

SHEET FLOW

Runoff that flows over the ground surface as a thin, even layer, not concentrated in a channel.

SOIL COVER COMPLEX METHOD

A method of runoff computation developed by the NRCS that is based on relating soil type and land use/cover to a runoff parameter called "curve number" (CN).

SOIL GROUP, HYDROLOGIC

A classification of soils by the Natural Resource Conservation Service into four runoff potential groups. The groups range from A soils, which are very permeable and produce little runoff, to D soils, which are not very permeable and produce much more runoff.

SPILLWAY

A depression in the embankment of a pond or basin that is used to pass peak discharge greater than the maximum design storm controlled by the pond.

STORAGE INDICATION METHOD

A reservoir routing procedure based on solution of the continuity equation (inflow minus outflow equals the change in storage) with outflow defined as a function of storage volume and depth.

STORM FREQUENCY

The number of times that a given storm event occurs or is exceeded on the average in a stated period of years. See "return period."

STORM SEWER

A system of pipes and/or open channels that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.

STORMWATER

The total amount of precipitation reaching the ground surface.

STORMWATER MANAGEMENT FACILITY

Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff. Typical stormwater management facilities include, but are not limited to, detention and retention basins, open channels, storm sewers, pipes, and infiltration structures.

STORMWATER MANAGEMENT PLAN

The plan for managing stormwater runoff in the Kishacoquillas Creek Watershed adopted by Mifflin County as required by the Act of October 4, 1978, P.L. 864, (Act 167),[4] and known as the "Kishacoquillas Creek Watershed Act 167 Stormwater Management Plan."

STORMWATER MANAGEMENT SITE PLAN

The plan prepared by the applicant or his representative indicating how stormwater runoff will be managed at the particular site of interest according to this article.

STREAM

A natural or man-made channel that conveys water in a concentrated manner. See also "ephemeral stream," "intermittent stream" and "perennial stream."

STREAM BUFFER

A vegetative strip paralleling the banks of a perennial or intermittent stream. The buffer shall contain appropriate vegetation through its width with the exception of a minimum five-foot-wide strip of land maintained in meadow grass or forbs at its outer boundary.

STREAM ENCLOSURE

A bridge, culvert or other structure in excess of 100 feet in length upstream to downstream which encloses a regulated water of this commonwealth.

SUBAREA

The smallest drainage unit of a watershed for which stormwater management criteria have been established in the stormwater management plan.

SUBDIVISION

The division or redivision of a lot, tract, or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land, including changes in existing lot lines for the purpose, whether immediate or future, of lease, transfer of ownership, or building or lot development; provided, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres, not involving any new street or easement of access or any residential dwellings, shall be exempt.

SWALE

A low-lying stretch of land that gathers or carries surface water runoff.

TIMBER OPERATIONS

See "forest management/timber operations."

TIME OF CONCENTRATION (TC)

The time for surface runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed. This time is the combined total of overland flow time and flow time in pipes or channels, if any.

TR-20

The computer-based hydrologic modeling technique adapted to the Kishacoquillas Creek Watershed for the Act 167 Plan. The model has been "calibrated" to reflect actual recorded flow values by adjusting key model input parameters.

TR-55

A method for determining runoff volumes and rates developed by the NRCS.

WATERCOURSE

A channel or conveyance of surface water having defined bed and banks, whether natural or artificial with perennial or intermittent flow.

WATERS OF THE COMMONWEALTH

Any and all rivers, streams, creeks, rivulets, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and all other bodies or channels of conveyance of surface and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of the Commonwealth of Pennsylvania.

WETLAND

Those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, ferns, and similar areas.

[1] Editor's Note: See 53 P.S. § 10101 et seq.

[2] Editor's Note: See 53 P.S. § 10101 et seq.

[3] Editor's Note: See 33 U.S.C. § 1251.

[4] Editor's Note: See 32 P.S. § 680.1 et seq.

§ 186-48 Stormwater management.

A. General requirements.

(1) All regulated activities in the Kishacoquillas Creek Watershed that do not fall under the exemption criteria shown in § 186-46E shall submit a drainage plan consistent with the Kishacoquillas Creek Watershed stormwater management plan to the municipality for review. These criteria shall apply to the total proposed development even if development is to take place in stages. Impervious cover shall include, but not be limited to, any roof, parking or driveway areas and any new streets and sidewalks.

(2) Stormwater drainage systems shall be provided in order to permit unimpeded flow along natural watercourses, except as modified by stormwater management facilities or open channels consistent with this article.

(3) The existing points of concentrated drainage that discharge onto adjacent property shall not be altered without permission of the adjacent property owner(s) and shall be subject to any applicable discharge criteria specified in this article.

(4) Areas of existing diffused drainage discharge shall be subject to any applicable discharge criteria in the general direction of existing discharge, whether proposed to be concentrated or maintained as diffused drainage areas, except as otherwise provided by this article. If diffused flow is proposed to be concentrated and discharged onto adjacent property [see Subsection A(3)], the applicant must demonstrate to the municipality in accordance with Subsection F that adequate downstream drainage conveyance facilities exist to safely transport the concentrated discharge, or the applicant must obtain drainage easements from affected downstream property owners and provide the facilities to safely convey the flow.

(5) Downstream hydraulic capacity analysis. Any downstream hydraulic capacity analysis conducted in accordance with this article shall use the following criteria for determining adequacy for accepting increased peak flow rates:

(a) Natural or man-made channels or swales must be able to convey the increased runoff associated with a two-year return period event within their banks at velocities consistent with protection of the channels from erosion. Acceptable velocities shall be based upon criteria included in the DEP Erosion and Sediment Control Program Manual.

(b) Natural or man-made channels or swales shall be designed to convey the increased twenty-five-year return period runoff without creating any hazard to persons or property.

(c) Culverts, bridges, storm sewers or any other facilities which must pass or convey flows from the upstream (i.e., off-site) area that contributes flow to that structure shall be designed in accordance with DEP, Chapter 105 regulations (if applicable) and, at a minimum, pass the increased twenty-five-year return period runoff.

(6) Where a development site is traversed by watercourse(s), stream buffers (see § 186-47B) shall be provided conforming to the line of such watercourses. The width of the buffers shall be determined as set forth in Subsection B(1)(c). It shall be prohibited to excavate, place fill, build structures, or make any alterations that may adversely affect the flow of stormwater within any portion of the stream buffer unless the proposed work is associated with a regulated wetlands mitigation program. The buffer shall be defined through a deed covenant or shown on an approved subdivision or land development plan that has been recorded.

(7) When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainageways shall be subject to approval by PADEP through the joint permit application process, or, where deemed appropriate by PADEP, through the general permit process.

(8) Any stormwater management facilities regulated by this article that would be located in or adjacent to waters of the commonwealth or wetlands shall be subject to approval by PADEP through the joint permit application process, or, where deemed appropriate by PADEP, the general permit process. When there is a question whether wetlands may be involved, it is the responsibility of the applicant or his agent to show that the land in question cannot be classified as wetlands, otherwise approval to work in the area must be obtained from PADEP.

(9) Any stormwater management facilities regulated by this article that would be located on or discharging into state highway rights-of-way shall be subject to approval by the Pennsylvania Department of Transportation (PennDOT).

(10) Minimization of impervious surfaces and infiltration of runoff through seepage beds, infiltration trenches, etc. are encouraged, where soil conditions permit, to reduce the size or eliminate the need for detention facilities.

(11) Roof drains must not be connected to sanitary sewers. Roof drains must not be connected to streets, storm sewers, or roadside ditches to promote overland flow and infiltration/percolation of stormwater. However, when it is more advantageous to connect directly to streets, storm sewers or roadside ditches, it shall be permitted on a case-by-case basis as determined by the Municipal Engineer.

B. Water quality requirements.

(1) The applicant shall comply with the following water quality requirements unless otherwise exempted by provisions of this article.

(a) Applicants will provide adequate storage and treatment facilities necessary to capture and treat a volume of stormwater runoff termed the "water quality volume" which is calculated in accordance with the following:

[1] The water quality volume (WQv) is the storage capacity needed to treat stormwater runoff equivalent to a minimum of the first 1.5 inches of runoff (from Appendix F, Pennsylvania Handbook of BMPs for Developing Areas, page F-2 for Region 2, value of 1.48 inches is rounded to 1.50 inches) from the developed areas of the site. The following calculation is used to determine the storage volume, WQv in acre-feet of storage:

	WQv = [(1.50)(Rv)(A)]/12
	Where:
		WQv	=	Water quality volume in acre-feet
		A	=	Area in acres
		Rv	=	0.05 + 0.009(I)
		I	=	Impervious cover in percent (e.g., I = 50 for 50% impervious cover)

[2] WQv shall be designed as part of a stormwater management facility which incorporates water quality BMPs as a primary benefit of using that facility, in accordance with design specifications contained in the Pennsylvania Handbook of BMPs for Developing Areas, 1998.

(b) The applicant shall first provide infiltration facilities in areas where soils are suitable for infiltration and shall direct the runoff from impervious surfaces into those infiltration facilities. A qualified soil scientist, geologist, or hydrogeologist shall characterize the infiltration characteristics of the site by conducting infiltration tests and developing a soil profile through test pitting in the proposed infiltration area. If the soils are not suitable for infiltration, the applicant shall submit documentation from a registered soil scientist, geologist, or hydrogeologist documenting the soil characteristics and receive a waiver from the Municipal Engineer. See Subsection C for the groundwater recharge requirements.

(c) If a perennial or intermittent stream passes through the development site, the applicant shall create a stream buffer conforming to the line of such watercourses and extending a minimum of 50 feet to either side of the top of the bank of the channel. The buffer area shall be maintained with appropriate vegetation as referenced in Appendix E of this chapter.[1] The municipality may select a smaller buffer width if desired, but never less than 10 feet. If the applicable rear or side yard setback is less than 50 feet, the buffer width may be reduced to 25% of the setback to a minimum of 10 feet. If an existing buffer is legally prescribed (e.g., deed covenant, easement, etc.) and it exceeds the requirements of this article, the existing buffer shall be maintained.

[1] Editor's Note: Said appendix is included as an attachment to this chapter.

(d) Detain the one-year, twenty-four-hour postdevelopment design storm runoff based on using the NRCS Type II distribution from the contributing watershed (after development). Provisions shall be made so that the detained runoff takes a minimum of 24 hours to drain from the facility from a point where the maximum volume of water is captured, (i.e., the maximum water surface elevation is achieved in the facility). Release of water can begin at the start of the storm (i.e., the invert of the water quality orifice is at the invert of the facility). The design of the facility shall consider and minimize the chances of clogging and sedimentation potential. The applicant may also utilize infiltration facilities in lieu of extended detention. The volume of infiltration provided for the contributing area may be deducted from the volume requirement for extended detention.

(2) The applicant shall submit designs for water quality facilities to the Municipal Engineer for review and approval. Such designs may achieve the water quality objectives through a combination of BMPs.

(3) In selecting the appropriate BMPs or combinations thereof, the applicant shall consider the following:

(a) Total contributing area.

(b) Permeability and infiltration rate of the site soils.

(c) Slope and depth to bedrock.

(d) Seasonal high water table.

(e) Proximity to building foundations and wellheads.

(f) Erodibility of soils.

(g) Land availability and configuration of the topography.

(h) Consistency with approved watershed and stormwater management plans or regulations.

(4) The following additional factors shall be considered when evaluating the suitability of BMPs used to control water quality at a given development site:

(a) Peak discharge and required volume control.

(b) Streambank erosion.

(c) Efficiency of the BMPs to mitigate potential water quality problems.

(d) The volume of runoff that will be effectively treated.

(e) The nature of the pollutant being removed.

(f) Maintenance requirements.

(g) Creation/protection of aquatic and wildlife habitat.

(h) Recreational value.

(i) Enhancement of aesthetic and property value.

(5) It is prohibited to discharge concentrated runoff (i.e., in channels, culverts, or storm sewers) into sinkholes unless prior approval is granted by the Municipal Engineer. If sinkholes develop during construction, the applicant shall seal and backfill the sinkhole in a manner acceptable to the Municipal Engineer. If existing sinkholes are to be sealed during construction, the applicant shall submit a sinkhole repair plan for approval by the Municipal Engineer.

C. Groundwater recharge requirements.

(1) The applicant shall maintain annual groundwater recharge consistent with predevelopment conditions, by infiltrating an amount of runoff equal to the recharge volume (based on the average annual infiltration rate based on the prevailing hydrologic soil groups present at a site). The recharge volume (Rev) may be part of the water quality volume. The groundwater recharge is calculated in accordance with the following formula, but shall not be less than the net increase in runoff from the two-year storm event:

	Rev = [(S)(Rv)(A)]/12
	Where:
		Rev	=	Recharge volume in acre-feet
		S	=	Soil specific recharge factor
		A	=	Area in acres
		Rv	=	0.05 + 0.009(I)
		I	=	Impervious cover in percent (e.g., I = 50 for 50% impervious cover)

(2) The soil specific recharge factor varies according to soil type. For the Kishacoquillas Creek Watershed, the following factors should be used:

	Hydrologic Soil Group	Soil Specific Recharge Factor (S)
	A	0.41
	B	0.27
	C	0.14
	D	0.07

D. Stormwater Management Districts.

(1) The Kishacoquillas Creek Watershed has been divided into two stormwater management districts as shown on the Watershed Map in Appendix D.[2]

[2] Editor's Note: Said appendix is on file in the Township offices.

(2) Standards for managing runoff from each subarea in the Kishacoquillas Creek Watershed for the two-, ten-, twenty-five-, fifty-, and one-hundred-year design storms are shown below. Development sites located in each of the districts must control postdevelopment runoff rates to predevelopment runoff rates for the design storms as follows:

	District	Control Criteria
	100%	Postdevelopment peak discharge for all design storms must be no greater than predevelopment peak discharges.
	75%	Postdevelopment peak discharge for all design storms must be no greater than 75% of the predevelopment peak discharges.

(3) If a proposed development located in a 75% release rate district incorporates infiltration facilities that achieve the groundwater recharge requirements specified in Subsection C, then the release rate for the development shall be increased to 100%.

E. Stormwater Management District implementation provisions (performance standards).

(1) General. Postdevelopment rates of runoff from any regulated activity shall not exceed the peak release rates of runoff prior to development for the design storms specified on the Stormwater Runoff Peak Rate Districts Map, Appendix D[3] and Subsection B, of this section.

[3] Editor's Note: Said appendix is on file in the Township offices.

(2) District boundaries. The boundaries of the Stormwater Management Districts are shown on an official map, which is available for inspection at the municipal office. A copy of the official map at a reduced scale is included in Appendix D[4] of this chapter. The exact location of the Stormwater Management District boundaries as they apply to a given development site shall be determined by mapping the boundaries using the two-foot topographic contours (or most accurate data required) provided as part of the drainage plan.

[4] Editor's Note: Said appendix is on file in the Township offices.

(3) Sites located in more than one district. For a proposed development site located within two or more release category subareas, the peak discharge rate from any subarea shall be the predevelopment peak discharge for each subarea multiplied by the applicable release rate. The calculated peak discharges shall apply regardless of whether the grading plan changes the drainage area by subarea. An exception to the above may be granted if discharges from multiple subareas recombine in proximity to the site. In this case, peak discharge in any direction may be a 100% release rate provided that the overall site discharge meets the weighted average release rate.

(4) Off-site areas. Off-site areas that drain through a proposed development site are not subject to release rate criteria when determining allowable peak runoff rates. However, on-site drainage facilities shall be designed to safely convey off-site flows through the development site.

(5) Site areas. Where the site area to be impacted by a proposed development activity differs significantly from the total site area, as determined by the Municipal Engineer, only the proposed development area and areas contributory to the proposed stormwater management facilities shall be subject to the release rate criteria.

(6) Regional detention alternatives. For certain areas within the study area, it may be more cost-effective to provide one control facility for more than one development site than to provide an individual control facility for each development site. The initiative and funding for any regional runoff control alternatives are the responsibility of prospective applicants. The design of any regional control basins must incorporate reasonable development of the entire upstream watershed. The peak outflow of a regional basin would be determined on a case-by-case basis using the hydrologic model of the watershed consistent with protection of the downstream watershed areas. "Hydrologic model" refers to the calibrated model as developed for the stormwater management plan.

F. Design criteria for stormwater management facilities.

(1) Any stormwater management facility (i.e., detention basin) designed to store runoff and requiring a berm or earthen embankment required or regulated by this article shall be designed to provide an emergency spillway to handle flow up to and including the one-hundred-year postdevelopment conditions. The height of the embankment must be set as to provide a minimum 1.0 foot of freeboard above the maximum pool elevation computed when the facility functions for the one-hundred-year postdevelopment inflow. Should any stormwater management facility require a dam safety permit under PADEP Chapter 105, the facility shall be designed in accordance with Chapter 105 and meet the regulations of Chapter 105 concerning dam safety which may be required to pass storms larger than one-hundred-year event.

(2) Any facilities that constitute water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures), and any work involving wetlands as directed in PADEP Chapter 105 regulations (as amended or replaced from time to time by PADEP), shall be designed in accordance with Chapter 105 and will require a permit from PADEP. Any other drainage conveyance facility that doesn't fall under Chapter 105 regulations must be able to convey, without damage to the drainage structure or roadway, runoff from the twenty-five-year design storm. Open channels shall be designed with a minimum of 1.0 foot of freeboard. Any facility that constitutes a dam as defined in PADEP Chapter 105 regulations may require a permit under dam safety regulations. Any facility located within a PennDOT right-of-way must meet PennDOT minimum design standards and permit submission requirements. If the primary drainage facilities do not have capacity for future flows, then a safe drainage path shall be provided to convey up to the one-hundred-year design storm without impacting structures.

(3) Storm sewers must be able to convey postdevelopment runoff from a ten-year design storm without surcharging inlets. Road culverts must be designed in accordance with PennDOT standards.

(4) Storm inlets, storm sewers, culverts, and open channels shall be designed without consideration of the impact of karst terrain on runoff rates.

(5) Adequate erosion protection shall be provided along all open channels, and at all points of discharge.

(6) The design of all stormwater management facilities shall incorporate sound engineering principles and practices. The Municipal Engineer shall reserve the right to disapprove any design that would result in the occurrence or continuation of an adverse hydrologic or hydraulic condition within the watershed.

(7) Storm drain conveyance system stability (swales, open channels, and pipe discharge aprons) shall be computed using a ten-year period peak runoff rate.

(8) Storm sewers, where required by zoning and land use densities, shall be placed under or immediately adjacent to the roadway side of the curb, or as directed by the Municipal Engineer, when parallel to the street within the right-of-way.

G. Calculation methodology. Stormwater runoff from all development sites shall be calculated using either the Rational Method or a soil cover complex methodology.

(1) Any stormwater runoff calculations involving drainage areas greater than 200 acres, including on- and off-site areas, shall use a generally accepted calculation technique that is based on the NRCS Soil Cover Complex Method. Table 7.307-1 summarizes acceptable computation methods. It is assumed that all methods will be selected by the design professional based on the individual limitations and suitability of each method for a particular site.

(2) All calculations consistent with this article using the Soil Cover Complex Method shall use the appropriate design rainfall depths for the various return period storms presented in Table A-1 in Appendix A of this chapter.[5] If a hydrologic computer model such as PSRM or HEC-1 is used for stormwater runoff calculations, then the duration of rainfall shall be 24 hours. The NRCS curve shown in Figure A-1, Appendix A of this chapter shall be used for the rainfall distribution.

[5] Editor's Note: Said appendix is included as an attachment to this chapter.

(3) For the purposes of predevelopment flow rate determination, undeveloped land shall be considered as "meadow" good condition, type "B" soil (RCN = 58, Rational "C" = 0.12), unless the natural ground cover generates a lower curve number or Rational "C" value (e.g., forest).

	Table 7.307-1
	Acceptable Computation Methodologies for Stormwater Management Plans
	Method	Method Developed By	Applicability
	TR-20 or commercial package based on TR-20	USDA-NRCS	When use of full model is desirable or necessary
	TR-55 or commercial package based on TR-55	USDA-NRCS	Applicable for plans within the models limitations
	HEC-HMS	United States Army Corps of Engineers	When use of full model is desirable or necessary
	PSRM	Penn State University	When use of full model is desirable or necessary
	Rational Method or commercial package based on Rational Method*	Emil Kuichling (1889)	For sites less than 200 acres
	Other methods	Various	As approved by the Municipal Engineer

	NOTES:
	*	Use of the Rational Method to estimate peak discharges from drainage areas that contain more than 100 acres must be approved by the Municipal Engineer.

(4) All calculations using the Rational Method shall use rainfall intensities consistent with appropriate times of concentration for overland flow and return periods from the design storm curves from the Pennsylvania Department of Transportation Design Rainfall Curves (1986) (Figure A-2). Times of concentration for overland flow shall be calculated using the methodology presented in Chapter 3 of Urban Hydrology for Small Watersheds, NRCS, TR-55 (as amended or replaced from time to time by NRCS). Times of concentration for channel and pipe flow shall be computed using Manning's Equation.

(5) Runoff curve numbers (RCN) for both existing and proposed conditions to be used in the Soil Cover Complex Method shall be obtained from Table A-2 in Appendix A of this chapter.[6]

[6] Editor's Note: Said appendix is included as an attachment to this chapter.

(6) Runoff characteristics of off-site areas that drain through a proposed development shall be based on actual existing conditions, not RCN = 58 or C = 0.12, and shall be assumed to not have any controls implemented on future development (i.e., no release rate restrictions).

(7) Runoff coefficients (C) for both existing and proposed conditions for use in the Rational Method shall be obtained from Table A-3 in Appendix A of this chapter.[7]

[7] Editor's Note: Said appendix is included as an attachment to this chapter.

(8) Where uniform flow is anticipated, the Manning's Equation shall be used for hydraulic computations, and to determine the capacity of open channels, pipes, and storm sewers. Values for Manning's roughness coefficient (n) shall be consistent with Table A-4 in Appendix A of this chapter.[8]

[8] Editor's Note: Said appendix is included as an attachment to this chapter.

(9) Outlet structures for stormwater management facilities shall be designed to meet the performance standards of this article using any generally accepted hydraulic analysis technique or method. Acceptable methods are presented in Handbook of Hydraulics, by King and Brater (McGraw Hill). In addition, application of computer programs such as HY-8 (Federal Highway Administration) or FlowMaster (Haestad Methods) will also be accepted.

(10) The design of any stormwater detention facilities intended to meet the performance standards of this article shall be verified by routing the design storm hydrograph through these facilities using the Storage Indication Method. For drainage areas greater than 20 acres in size, the design storm hydrograph shall be computed using a calculation method that produces a full hydrograph. The municipality may approve the use of any generally accepted full hydrograph approximation technique that shall use a total runoff volume that is consistent with the volume from a method that produces a full hydrograph.

(11) The municipality has the authority to require that computed existing runoff rates be reconciled with field observations and conditions. If the designer can substantiate through actual physical calibration that more appropriate runoff and time of concentration values should be utilized at a particular site, then appropriate variations may be made upon review and recommendations of the Municipal Engineer. Calibration shall require detailed gauge and rainfall data for the particular site in question.

H. Erosion and sedimentation requirements.

(1) Whenever the vegetation and topography are to be disturbed, such activity must be in conformance with Chapter 102, Title 25, Rules and Regulations, Part I, Commonwealth of Pennsylvania, Department of Environmental Protection, Subpart C, protection of Natural Resources, Article II, Water Resources, Chapter 102, "Erosion Control," and in accordance with the Mifflin County Conservation District and the standards and specifications of the municipality.

(2) Additional erosion and sedimentation control design standards and criteria that must be or are recommended to be applied where infiltration BMPs are proposed and include the following:

(a) Areas proposed for infiltration BMPs shall be protected from sedimentation and compaction during the construction phase, so as to maintain their maximum infiltration capacity.

(b) In order to insure compliance with Chapter 102, the timing of the installation and operation of the infiltration BMP shall be at the discretion of the Municipal Engineer.

§ 186-49 Drainage plan requirements.

A. General requirements. For any of the activities regulated by this article, the final approval of subdivision and/or land development plans, the issuance of any building or occupancy permit, or the commencement of any land disturbance activity may not proceed until the applicant or his/her agent has received written approval of a drainage plan from the municipality.

B. Drainage plan contents.

(1) The drainage plan shall consist of all applicable calculations, maps, and plans. A note on the maps shall refer to the associated computations and erosion and sedimentation control plan by title and date. The cover sheet of the computations and erosion and sedimentation control plan shall refer to the associated maps by title and date. All drainage plan materials shall be submitted to the municipality in a format that is clear, concise, legible, neat, and well organized; otherwise, the drainage plan shall be disapproved and returned to the applicant.

(2) The following items shall be included in the drainage plan:

(a) General.

[1] General description of project.

[2] General description of permanent stormwater management techniques, including construction specifications of the materials to be used for stormwater management facilities.

[3] Complete hydrologic, hydraulic, and structural computations for all stormwater management facilities.

(b) Map(s) of the project area shall be submitted on twenty-four-inch-by-thirty-six-inch sheets and shall be prepared in a form that meets the requirements of the applicable subdivision and land development ordinance then in effect (either this chapter of the Township of Derry or, if no Subdivision and Land Development Ordinance has been adopted by the Township of Derry, then the Subdivision Ordinance and Land Development Ordinance of the County of Mifflin, Pennsylvania) and for recording at the offices of the Recorder of Deeds of Mifflin County. The contents of the maps(s) shall include, but not be limited to:

[1] The location of the project relative to highways, municipalities or other identifiable landmarks.

[2] Existing contours at intervals of two feet. In areas of steep slopes (greater than 15%), five-foot contour intervals may be used.

[3] Existing streams, lakes, ponds, or other bodies of water and wetlands within the project area.

[4] Other physical features, including flood hazard boundaries, sinkholes, streams, existing drainage courses, areas of natural vegetation to be preserved, and the total extent of the upstream area draining through the site.

[5] The locations of all existing and proposed structures and utilities within 50 feet of property lines.

[6] An overlay showing soil names and boundaries.

[7] Proposed changes to the land surface and vegetative cover, including the type and amount of impervious area that would be added.

[8] Proposed structures, roads, paved areas, and buildings.

[9] Final contours at intervals at two feet. In areas of steep slopes (greater than 15%), five-foot contour intervals may be used.

[10] The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.

[11] The date of the plan, including revisions.

[12] A graphic and written scale of a minimum one inch equals no more than 50 feet.

[13] A North arrow.

[14] The total tract boundary and size with distances marked to the nearest foot and bearings to the nearest degree.

[15] Existing and proposed land use(s).

[16] Vertical profiles of all proposed open channels and storm sewers, including hydraulic capacity.

[17] Overland drainage paths of proposed swales or channels to convey water.

[18] A construction detail of any improvements made to sinkholes and the location of all notes to be posted, as specified in this chapter.

[19] A statement, signed by the landowner, acknowledging the stormwater management system to be a permanent fixture that can be altered or removed only after approval of a revised plan by the municipality.

[20] The following signature block for the design engineer:

"(Design Engineer), on this date (date of signature), has reviewed and hereby certifies that the drainage plan meets all design standards and criteria of the Kishacoquillas Creek Watershed Act 167 Stormwater Management Ordinance."

(c) Supplemental information.

[1] A written description of the following information shall be submitted.

[a] The overall stormwater management concept for the project.

[b] Stormwater runoff computations as specified in this article.

[c] Stormwater management techniques to be applied both during and after development.

[d] Expected project time schedule.

[2] A soil erosion and sedimentation control plan, where applicable, including all reviews and approvals, as required by PADEP.

[3] A geologic assessment of the effects of runoff on sinkholes as specified in this article.

[4] The effect of the project (in terms of runoff volumes and peak flows) on adjacent properties and on any existing municipal stormwater collection system that may receive runoff from the project site.

[5] A declaration of adequacy and highway occupancy permit from the PennDOT district office when utilization of a PennDOT storm drainage system is proposed.

(d) Stormwater management facilities.

[1] All stormwater management facilities must be located on a plan and described in detail.

[2] When groundwater recharge methods such as seepage pits, beds or trenches are used, the locations of existing and proposed septic tank infiltration areas and wells must be shown.

[3] All calculations, assumptions, and criteria used in the design of the stormwater management facilities must be shown.

C. Plan submission. For all activities regulated by this article, the steps below shall be followed for submission. For any activities that require a PADEP joint permit application and regulated under Chapter 105 (Dam Safety and Waterway Management) or Chapter 106 (Floodplain Management) of PADEP's rules and regulations, require a PennDOT highway occupancy permit, or require any other permit under applicable state or federal regulations, the permit(s) shall be part of the plan.

(1) The drainage plan shall be submitted by the applicant as part of the preliminary plan submission for the regulated activity.

(2) Four copies of the drainage plan shall be submitted.

(3) Distribution of the drainage plan will be as follows:

(a) Two copies to the municipality accompanied by the requisite municipal review fee, as specified in this article.

(b) One copy to the Municipal Engineer.

(c) One copy to the County Planning Commission/Department.

D. Drainage plan review.

(1) The Municipal Engineer shall review the drainage plan for consistency with the adopted Kishacoquillas Creek Watershed Act 167 stormwater management plan. The municipality shall require receipt of a complete plan, as specified in this article.

(2) The Municipal Engineer shall review the drainage plan for any submission or land development against provisions of this chapter not superseded by this article.

(3) For activities regulated by this article, the Municipal Engineer shall notify the municipality, in writing, whether the drainage plan is consistent with the stormwater management plan. Should the drainage plan be determined to be consistent with the stormwater management plan, the Municipal Engineer will forward an approval letter to the developer with a copy to the Municipal Secretary.

(4) Should the drainage plan be determined to be inconsistent with the stormwater management plan, the Municipal Engineer will forward a disapproval letter to the applicant with a copy to the Municipal Secretary citing the reason(s) for the disapproval. Any disapproved drainage plans may be revised by the applicant and resubmitted consistent with this article.

(5) For regulated activities specified in § 186-46D(4)(c) and (d) of this article, the Municipal Engineer shall notify the Municipal Building Permit Officer, in writing, within a time frame consistent with Chapter 97, Construction Codes, Uniform, and/or this chapter, whether the drainage plan is consistent with the stormwater management plan and forward a copy of the approval/disapproval letter to the applicant. Any disapproved drainage plan may be revised by the applicant and resubmitted consistent with this article.

(6) For regulated activities requiring a PADEP joint permit application, the Municipal Engineer shall notify PADEP whether the drainage plan is consistent with the stormwater management plan and forward a copy of the review letter to the municipality and the applicant. PADEP may consider the Municipal Engineer's review comments in determining whether to issue a permit.

(7) The municipality shall not approve any subdivision or land development for regulated activities specified in § 186-46D(4)(a) and (b) of this article if the drainage plan has been found to be inconsistent with the stormwater management plan, as determined by the Municipal Engineer. All required permits from PADEP must be obtained prior to approval.

(8) The municipal building permit office shall not issue a building permit for any regulated activity specified in § 186-46D of this article if the drainage plan has been found to be inconsistent with the stormwater management plan, as determined by the Municipal Engineer, or without considering the comments of the Municipal Engineer. All required permits from PADEP must be obtained prior to issuance of a building permit.

(9) The developer shall be responsible for completing an as-built survey of all stormwater management facilities included in the approved drainage plan. The as-built survey and an explanation of any discrepancies with the design plans shall be submitted to the Municipal Engineer for final approval. In no case shall the municipality approve the as-built survey until the municipality receives a copy of an approved declaration of adequacy, highway occupancy permit from the PennDOT district office, and any applicable permits from PADEP.

(10) The municipality's approval of a drainage plan shall be valid for a period not to exceed one year. This one-year time period shall commence on the date that the municipality signs the approved drainage plan. If stormwater management facilities included in the approved drainage plan have not been constructed, or if an as-built survey of these facilities has not been approved within this one-year time period, then the municipality may consider the drainage plan disapproved and may revoke any and all permits. Drainage plans that are considered disapproved by the municipality shall be resubmitted in accordance with Subsection F of this section.

E. Modification of plans.

(1) A modification to a submitted drainage plan for a development site that involves a change in stormwater management facilities or techniques, or that involves the relocation or redesign of stormwater management facilities, or that is necessary because soil or other conditions are not as stated on the drainage plan as determined by the Municipal Engineer, shall require a resubmission of the modified drainage plan consistent with Subsection C of this section and be subject to review as specified in Subsection D of this section.

(2) A modification to an already approved or disapproved drainage plan shall be submitted to the municipality, accompanied by the applicable review fee. A modification to a drainage plan for which a formal action has not been taken by the municipality shall be submitted to the municipality, accompanied by the applicable fee.

F. Resubmission of disapproved drainage plans. A disapproved drainage plan may be resubmitted, with the revisions addressing the Municipal Engineer's concerns documented in writing, to the Municipal Engineer in accordance with Subsection C of this section and be subject to review as specified in Subsection D of this section. The applicable municipality review fee must accompany a resubmission of a disapproved drainage plan.

§ 186-50 Inspections.

A. Schedule of inspections.

(1) The Municipal Engineer or his municipal assignee shall inspect all phases of the installation of the permanent stormwater management facilities.

(2) During any stage of the work, if the Municipal Engineer determines that the permanent stormwater management facilities are not being installed in accordance with the approved stormwater management plan, the municipality shall revoke any existing municipal permits or issue a stop-work order until the work is corrected or a revised drainage plan is submitted and approved, as specified in this article.

§ 186-51 Fees and expenses.

A. General. The fee required by this article is the municipal review fee. The municipal review fee shall be established by the municipality to defray review costs incurred by the municipality and the Municipal Engineer. All fees shall be paid by the applicant.

B. Municipality drainage plan review fee. The municipality shall establish a review fee schedule by separate resolution of the municipal governing body based on the size of the regulated activity and based on the municipality's costs for reviewing drainage plans. The municipality shall periodically update the review fee schedule to ensure that review costs are adequately reimbursed.

C. Expenses covered by fees. The fees required by this article shall, at a minimum, cover:

(1) Administrative costs.

(2) The review of the drainage plan by the municipality and the Municipal Engineer.

(3) The site inspections.

(4) The inspection of stormwater management facilities and drainage improvements during construction.

(5) The final inspection upon completion of the stormwater management facilities and drainage improvements presented in the drainage plan.

D. Additional costs. The developer will be invoiced for any additional costs incurred by the municipality in the course of reviewing the development plan. These costs may include, but are not limited to, special studies by qualified engineers or surveyors, field reconnaissance, and testing.

§ 186-52 Maintenance responsibilities.

A. Performance guarantee. The applicant shall provide a financial guarantee to the municipality for the timely installation and proper construction of all stormwater management controls as required by the approved stormwater plan and this article equal to 110% of the estimated construction cost, as completed, of the required controls.

B. Maintenance responsibilities.

(1) The drainage plan for the development site shall contain an operation and maintenance plan prepared by the applicant and approved by the Municipal Engineer. The operation and maintenance plan shall outline required routine maintenance actions and schedules necessary to insure proper operation of the facility(ies).

(2) The drainage plan for the development site shall establish responsibilities for the continuing operating and maintenance of all proposed stormwater control facilities, consistent with the following principles:

(a) If a development consists of structures or lots that are to be separately owned and in which streets, sewers and other public improvements are to be dedicated to the municipality, stormwater control facilities may also be dedicated to and maintained by the municipality.

(b) If a development site is to be maintained in a single ownership or if sewers and other public improvements are to be privately owned and maintained, then the ownership and maintenance of stormwater control facilities shall be the responsibility of the owner or private management entity.

(3) The governing body, upon recommendation of the Municipal Engineer, shall make the final determination on the continuing maintenance responsibilities prior to final approval of the drainage plan. The municipality reserves the right to accept the ownership and operating responsibility for any or all of the stormwater management controls.

C. Maintenance agreement for privately owned stormwater facilities.

(1) Prior to final approval of the site's stormwater management plan, the property owner shall sign and record a maintenance agreement covering all stormwater control facilities that are to be privately owned. Said agreement shall be substantially in the form of the agreement, designated as Appendix C, that is attached and made part hereto.[1]

[1] Editor's Note: Said appendix is included as an attachment to this chapter.

(2) Other items may be included in the agreement where determined necessary to guarantee the satisfactory maintenance of all facilities. The maintenance agreement shall be subject to the review and approval of the Municipal Solicitor and governing body.

D. Municipal Stormwater Maintenance Fund.

(1) If stormwater facilities are accepted by the municipality for dedication, persons installing stormwater storage facilities shall be required to pay a specified amount to the Municipal Stormwater Maintenance Fund to help defray costs of periodic inspections and maintenance expenses. Payment can be in the form of an irrevocable letter of credit, a restricted escrow account, or a corporate security bond. The amount of the deposit shall be determined as follows:

(a) If the storage facility is to be owned and maintained by the municipality, the deposit shall cover the estimated costs for maintenance and inspections for two years. The Municipal Engineer will establish the estimated costs utilizing information submitted by the applicant.

(b) The amount of the deposit to the fund shall be converted to present worth of the annual series values. The Municipal Engineer shall determine the present worth equivalents, which shall be subject to the approval of the municipal governing body.

(2) If a storage facility is proposed that also serves as a recreation facility (e.g., ball field, pond), the municipality may reduce or waive the amount of the maintenance fund deposit based upon the value of the land for public recreation purpose.

(3) If at some future time, a storage facility (whether publicly or privately owned) is eliminated due to the installation of storm sewers or other storage facility, the unused portion of the maintenance fund deposit will be applied to the cost of abandoning the facility and connecting to the storm sewer system or other facility. Any amount of the deposit remaining after the costs of abandonment are paid will be returned to the depositor.

E. Postconstruction maintenance inspections.

(1) Stormwater detention and retention basins or facilities shall be inspected by, or under the direction of a registered professional engineer on behalf of the landowner/applicant or responsible entity (including the Municipal Engineer for dedicated facilities) on the following basis:

(a) Annually for the first five years.

(b) Once every three years thereafter.

(c) During or immediately after the cessation of a one-hundred-year or greater storm event.

(2) The entity conducting the inspection shall be required to submit a report to the municipality within one month following completion of the inspection. The report will present documentation regarding the condition of the facility and recommending necessary repairs, if needed. Any needed repairs shall be implemented by the owner within one month of the report issuance date.

§ 186-53 Enforcement and penalties.

A. Right of entry. Upon presentation of proper credentials, duly authorized representatives of the municipality may enter at reasonable times upon any property within the municipality to inspect the condition of the stormwater structures and facilities in regard to any aspect regulated by this article.

B. Notification. In the event that a person fails to comply with the requirements of this article, or fails to conform to the requirements of any permit issued hereunder, the municipality shall provide written notification of the violation. Such notification shall set forth the nature of the violation(s) and establish a time limit for correction of these violations(s). Failure to comply within the time specified shall subject such person to the penalty provision of this article. All such penalties shall be deemed cumulative and shall not prevent the municipality from pursuing any and all other remedies. It shall be the responsibility of the owner of the real property on which any regulated activity is proposed to occur, is occurring, or has occurred, to comply with the terms and conditions of this article.

C. Enforcement. The municipality is hereby authorized and directed to enforce all of the provisions of this article. All inspections regarding compliance with the drainage plan shall be the responsibility of the Municipal Engineer or other qualified persons designated by the municipality.

(1) A set of design plans approved by the municipality shall be on file at the site throughout the duration of the construction activity. Periodic inspections may be made by the municipality or its designee during construction.

(2) It shall be unlawful for any person, firm or corporation to undertake any regulated activity under § 186-46D on any property except as provided for in the approved drainage plan and pursuant to the requirements of this article. It shall be unlawful to alter or remove any control structure required by the drainage plan pursuant to this article or to allow the property to remain in a condition which does not conform to the approved drainage plan.

(3) At the completion of the project, and as a prerequisite for the release of the performance guarantee, the applicant or his representatives shall:

(a) Provide a certification of completion from an engineer, architect, surveyor or other qualified person verifying that all permanent facilities have been constructed according to the plans and specifications and approved revisions thereto.

(b) Provide a printed set of as-built drawings to the municipality.

(4) After receipt of the certification by the municipality, a final inspection shall be conducted by the municipality or its designee to certify compliance with this article.

(5) Suspension and revocation of permits.

(a) Any municipal permit issued under this article may be suspended or revoked or a stop-work order may be issued by the governing body for:

[1] Noncompliance with or failure to implement any provision of the permit.

[2] A violation of any provision of this article or any other applicable law, ordinance, rule or regulation relating to the project.

[3] The creation of any condition or the commission of any act during construction or development which constitutes or creates a hazard or nuisance, pollution or which endangers the life or property of others.[1]

[1] Editor's Note: Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I).

(b) A suspended permit shall be reinstated by the municipality when:

[1] The Municipal Engineer or his designee has inspected and approved the corrections to the stormwater management and erosion and sediment pollution control measure(s), or the elimination of the hazard or nuisance; and/or

[2] The municipality is satisfied that the violation of the ordinance, law, or rule and regulation has been corrected.

[3] A permit that has been revoked by the municipality cannot be reinstated. The applicant may apply for a new permit under the procedures outlined in this article.

(6) Occupancy permit. An occupancy permit shall not be issued by the municipality unless all requirements of this article have been met. The occupancy permit shall be required for each lot owner and/or applicant for all subdivisions and land development in the municipality.

D. Public nuisance.

(1) The violation of any provision of this article is hereby deemed a public nuisance.

(2) Each day that a violation continues shall constitute a separate violation.

E. Enforcement remedies.

(1) Anyone violating the provisions of this article shall be guilty of a summary offense, and upon conviction shall be subject to a fine of not more than $1,000 for each violation plus court costs or imprisonment of not more than 90 days, or both. Each day that the violation continues shall be a separate offense.

(2) In addition, the municipality, through its solicitor, may institute injunctive, mandamus or any other appropriate action or proceeding at law or in equity for the enforcement of this article. Any court of competent jurisdiction shall have the right to issue restraining orders, temporary or permanent injunctions, mandamus or other appropriate forms of remedy or relief.

F. Compatibility with other ordinance requirements. Approvals issued pursuant to this article do not relieve the applicant of the responsibility to comply with or to secure required permits or approvals for activities regulated by any other applicable codes, rules, statutes, or ordinances.

G. Appeals.

(1) Any person aggrieved by any action of the municipality or its designee, relevant to the provisions of this article, may appeal to the municipality within 30 days of that action.

(2) Any person aggrieved by any decision of the municipality, relevant to the provisions of this article, may appeal to the County Court of Common Pleas in the county where the activity has taken place within 30 days of the municipality's decision.