Arvada, CO Environmental Rules: Stormwater Management (2026)

Section 50-21 explains that the city operates its MS4 'to promote the safe, efficient, and effective drainage of stormwater and other runoff or discharges' and protects water quality 'to the maximum extent practicable' from pollutants entering through land disturbance during construction. S. Title 31, Articles 15 and 35, and in the Engineering Code of Standards and Specifications. The core prohibition, Section 50-72(a), bars discharging or spilling any substance other than naturally occurring stormwater runoff into the MS4, but 14 exceptions keep everyday activity legal, including uncontaminated pumped groundwater, landscape irrigation return flow, rising groundwater, air conditioning condensation, individual or residential car washing, water incidental to street sweeping, agricultural stormwater runoff, and discharges already authorized by a Colorado Discharge Permit System or NPDES permit.

Section 50-74 separately makes several related acts unlawful: false statements in a stormwater application or report, failing to maintain required best management practices (BMP) and drainage facilities, failing to keep an erosion and sediment control plan on site, refusing an inspection, maintaining an illicit connection to the MS4, and storing construction or landscape materials on public right-of-way without authorization. The director, defined in Section 50-23, has right-of-entry authority under Section 50-39 to inspect for illegal discharges or connections, including obtaining a warrant if entry is refused and there is a serious threat to public health or safety.