Upper Darby, PA Environmental Rules: Stormwater Management (2026)

Chapter 465, adopted March 16, 2005 by Ordinance No. 2945 and re-enacted in its entirety September 21, 2022 by Ordinance No. 3125, governs stormwater in the Township. Section 465-14 bars any regulated activity from starting until the municipality issues approval of an SWM plan showing compliance with the chapter, and that plan must apply to the total proposed development even when construction happens in stages. Small projects are not automatically off the hook: under § 465-6, a 150-square-foot shed built after adoption is exempt from water-quality and quantity requirements, but if the same owner later adds a 499-square-foot room, the Simplified Method applies to the full 649 square feet added since the ordinance took effect, and a further 700-square-foot pool or patio pushes the owner into full quantity-and-quality submission requirements for the cumulative 1,349 square feet.

Section 465-14H requires a 25-foot drainage easement on each side of any stream crossing a development site, and concentrated stormwater discharged directly onto adjacent property is strictly prohibited. Plan review and construction inspection are funded by fees the Township sets by resolution under § 465-33, covering administrative costs, engineer review, site inspections and final inspection under § 465-34. The municipal Engineer or a designee conducts periodic inspections during construction under § 465-53, and an occupancy permit will not issue until the owner files an engineer's certification of completion under § 465-53E.