Arizona Stormwater Management Law: Statewide Environmental Rules Rules (2026)

Key Facts

Statute: ARS 49-255 et seq.
Regulator: Arizona DEQ
Construction Threshold: One acre disturbed
Max Penalty: $25,000 per day

Full Breakdown

ARS 49-255 et seq. authorizes the Arizona Department of Environmental Quality to administer the Arizona Pollutant Discharge Elimination System (AZPDES). Construction sites disturbing one or more acres must obtain coverage under the AZPDES Construction General Permit, prepare a Stormwater Pollution Prevention Plan, and install best management practices. Municipal Separate Storm Sewer Systems (MS4s) in larger cities operate under individual or general permits. Local stormwater ordinances may add controls but cannot replace state permit obligations.

Violations & Penalties

AZPDES violations carry civil penalties up to $25,000 per day per violation under ARS 49-262, plus potential criminal liability for knowing discharges and required corrective action.

Frequently Asked Questions

When does an Arizona construction site need an AZPDES stormwater permit?

Permit coverage is required when site grading or clearing will disturb one acre or more, or when smaller sites are part of a larger common plan of development that exceeds the one-acre threshold.

Do Arizona cities issue stormwater permits or ADEQ?

ADEQ issues the AZPDES permit and enforces statewide. Cities operating MS4s have their own permits and may require local grading permits, but the state discharge permit is mandatory and not delegable.

Arizona AZPDES Stormwater Permit Statewide Requirements

Key Facts

Full Breakdown

Violations & Penalties

Frequently Asked Questions

Sources

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