Las Cruces, NM Environmental Rules: Stormwater Management (2026)

The stormwater ordinance sits at Land Development Code Chapter 34, Article III, adopted to keep pollutants out of the city's municipal separate storm sewer system (MS4) under Section 34-125. Section 34-130's general prohibition bars introducing anything but stormwater into the MS4 or city waterways, though narrow affirmative defenses cover things like firefighting runoff, residential lawn watering, and uncontaminated groundwater. Section 34-131 spells out specific banned discharges: used motor oil, industrial or hazardous waste, septic and grease-trap waste, commercial car-wash wastewater, swimming pool and spa backwash, ready-mix concrete washout, and any release from a leaking petroleum storage tank.

The director of public works, appointed under Section 34-127, administers the program, inspects the MS4 annually, and runs a program to find and eliminate illicit connections. Construction sites disturbing one acre or more must follow Section 34-133, using the state DOT's Storm Water Management Guidelines for BMP and SWPPP design, filing an EPA Notice of Intent before starting earthwork, and inspecting disturbed areas at least twice a month and within 24 hours of any rainfall of half an inch or more. A written erosion and sediment control plan on an 18-by-24-inch sheet is required for any site of one acre or more.

Anyone who spills a reportable quantity of a hazardous substance into the MS4 must notify the fire department, public works, and the floodplain administrator immediately and file a written report within 14 days, then reimburse the city for cleanup costs within 30 days of being invoiced. Codes officers and police can issue administrative warnings and stop-work orders under Section 34-135, and criminal citations under Section 34-137.