This chapter shall be known and may be cited as the "Halfmoon Township Stormwater Management Ordinance."
The governing body of the municipality finds that:
A. 
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.
B. 
This chapter has been developed considering the actual hydrologic processes that occur within the Spring Creek Watershed and how these processes can best be represented in hydrologic models that are used in engineering practice to model developing areas for stormwater management purposes. Process driven stormwater management planning is critical in the Spring Creek Watershed due to the underlying geology. The Spring Creek Watershed is mainly underlain by carbonate formations. As a result, significant areas within the watershed do not produce overland or surface runoff, but rather contribute to the storm flow component of runoff in larger tributary areas via a greater than normal interflow component.
C. 
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.
The purpose of this chapter is to promote health, safety, and welfare within Halfmoon Township by minimizing the damages described in § 200-2A of this chapter through provisions designed to:
A. 
Manage accelerated runoff and erosion and sedimentation problems at their source by regulating activities that cause these problems.
B. 
Utilize and preserve the existing natural drainage systems.
C. 
Encourage the use of low-impact development techniques to promote infiltration and groundwater recharge where appropriate.
D. 
Maintain existing flows and quality of streams and watercourses in the municipality and the commonwealth.
E. 
Preserve and restore the flood-carrying capacity of streams.
F. 
Provide proper maintenance of all permanent stormwater management facilities that are constructed in the basin.
G. 
Provide performance standards and design criteria for watershed-wide stormwater management and planning.
H. 
Protect groundwater and surface water quality.
The municipality is empowered to regulate land use activities that affect runoff by the authority by the Act of October 4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1 et seq., as amended, the "Stormwater Management Act," and Act 247, the PA Municipal Planning Code (as amended).[1]
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
A. 
This chapter shall apply to all land and watercourses within Halfmoon Township.
B. 
This chapter shall only apply to permanent stormwater management facilities constructed as part of any of the regulated activities listed in this section. Stormwater management and erosion and sediment pollution control during construction activities are specifically not regulated by this chapter, but shall continue to be regulated under existing laws and ordinances.
C. 
The following activities are defined as "regulated activities" and shall be regulated by this chapter:
(1) 
Land development.
(2) 
Subdivision.
(3) 
Construction of new or additional impervious or semipervious surfaces (roadways, driveways, parking lots, etc.).
(4) 
Construction of new buildings or additions to existing buildings.
(5) 
Diversion or piping of any natural or man-made stream channel.
(6) 
Installation of stormwater management facilities or appurtenances thereto.
Any ordinance or ordinance provision of the municipality inconsistent with any of the provisions of this chapter is hereby repealed to the extent of the inconsistency only. For all matters regulated by this chapter, Ordinance No. 96-5 is hereby repealed.
Approvals issued pursuant to this chapter 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.
The granting of any exemption, permit, or approval by the municipality does not relieve the applicant from assuring that stormwater runoff from the development site will not cause injury or damage to other persons or property.
Specific methods and publications indicated in this chapter shall, in all cases, refer to the latest available edition and include revisions or amendments thereto.
A. 
Activities identified below are exempt from the requirement to submit a stormwater management plan to the governing municipality for review. Exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. These measures include adequate and safe conveyance of stormwater on the site and as it leaves the site. This exemption shall not relieve the applicant from meeting the special requirements for water quality and groundwater recharge for high quality (HQ) and exceptional value (EV) watersheds (DEP Chapter 93 and antidegradation requirement), and § 200-16C and E of this chapter relative to recharge and water quality volume requirements.
(1) 
All development activities having impervious coverage of less than 10% of the total site area up to a maximum impervious area of 10,000 square feet. However, adequate and safe conveyance of stormwater from the site must be provided. For developments that are to be constructed in phases, the sum of all final phases must be considered in establishing exemption eligibility. Impervious cover shall include, but not be limited to, any roof, parking or driveway areas, and any new streets and sidewalks, or bikeways.
(2) 
Land disturbance associated with the construction or alteration of one- and two-family dwellings, provided that the disturbance does not alter any stormwater condition beyond the boundaries of the lot or alter provisions of a previously approved stormwater management plan for the lot or encompassing subdivision. Multiple (greater than two) lot subdivisions cannot be exempted.
(3) 
Any site less than one acre in size that decreases the total site impervious area following development and:
(a) 
Is not located within a recognized sensitive area (as defined in Article II, Definitions, of this chapter);
(b) 
Is not defined as a water quality sensitive (WQS) development (as defined in Article II, Terminology, and Appendix B, Maps[1]); or
[1]
Editor's Note: Appendix B is included at the end of this chapter.
(c) 
Is not located in an area where existing downstream stormwater problems are known to occur (the Municipal Engineer shall make the final determination as to preexisting problems, but the municipality must have supporting documentation of past problems).
(4) 
In addition, the Municipal Engineer may waive the requirement to prepare a stormwater management plan for sites larger than one acre for which the overall site impervious area is being decreased, and which meets the other conditions identified above.
B. 
The diversion or piping of any natural or man-made stream channel and/or for the installation of stormwater management facilities or modifications thereto cannot be exempted. These activities always require the submission of a stormwater management plan. Exemptions in Subsection A(1) and (2) cannot be combined for use with small residential subdivisions.
C. 
In addition to the general exemptions identified above, exemptions for specific technical criteria are identified where applicable in Article III.
The degree of stormwater management sought by the provisions of this chapter is considered reasonable for regulatory purposes. This chapter shall not create liability on the part of the municipality, any appointed or elected official of the municipality, the Centre County Conservation District, or any officer, engineer, or employee thereof for the erosion, sedimentation, or flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.