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Pennsylvania Statewide Rule

Pennsylvania Storm Water Management Act Watershed Rules

Heavy RestrictionsApplies statewide across Pennsylvania (2026)

Key Facts

Citation
Act 167 of 1978
Adoption deadline
Six months post-approval
Lead agency
PA DEP
Tied permit
MS4 NPDES
Last verified: August 21, 2026Source: Commonwealth of Pennsylvania

Summary

The Pennsylvania Storm Water Management Act (Act 167 of 1978) requires counties to prepare watershed-based stormwater plans and obligates municipalities to adopt implementing ordinances meeting state release-rate and water-quality standards.

Within six months following adoption and approval of the watershed storm water plan, each municipality shall adopt or amend, and shall implement such ordinances and regulations, including zoning, subdivision and development, building code, and erosion and sedimentation ordinances, as are necessary to regulate development within the municipality in a manner consistent with the applicable watershed storm water plan and the provisions of this act.

Source: Commonwealth of PennsylvaniaView official code

Full Breakdown

Act 167, codified at 32 P.S. Sections 680.1-680.17, directs the Department of Environmental Protection to coordinate watershed stormwater plans. Counties prepare plans and municipalities within the watershed must adopt or amend ordinances within six months of plan approval. Plans set peak discharge release rates, infiltration requirements, and water-quality controls aligned with Pennsylvania's MS4 NPDES permits. Developers triggering earth disturbance generally must demonstrate post-construction stormwater management consistent with the plan.

Violations & Penalties

Failure of a municipality to adopt a plan may forfeit DEP grant eligibility. Developer noncompliance can lead to DEP civil penalties up to $10,000 per day under the Clean Streams Law.

Frequently Asked Questions

Are all Pennsylvania municipalities required to have stormwater ordinances?
Municipalities in watersheds with approved Act 167 plans must adopt conforming ordinances. MS4-regulated municipalities must additionally meet NPDES permit minimum control measures.
Who enforces stormwater violations during construction in Pennsylvania?
DEP and delegated county conservation districts enforce earth-disturbance and post-construction stormwater requirements, often jointly with municipal engineers under the local ordinance.

Sources

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