Environmental Rules in Hawthorne, CA (2026)
4 verified environmental rules for Hawthorne, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
Stormwater Management
Hawthorne Chapter 8.50 bans any illicit discharge into the city's storm drain (MS4) system unless it is an NPDES-authorized nonstormwater flow, firefighting runoff, or an RWQCB-LA exempt discharge. The chapter also bars illicit connections, dumping and industrial pollutant discharges, backed by public works enforcement and misdemeanor penalties.
Hawthorne Stormwater Discharge and Pollution Rules
Significant RestrictionsHawthorne Code § 8.50.020
No person shall cause any illicit discharge to enter the MS4 unless such discharge: (1) consists of nonstormwater that is authorized by an NPDES permit; or (2) is associated with fire fighting activities; or (3) is a discharge which is exempt or conditionally exempt in accordance with an applicable order of the RWQCB-LA.
Erosion Control
Hawthorne requires construction sites to deploy sediment barriers, silt fencing, tracking controls and slope erosion measures to keep runoff to the maximum extent practicable, and to submit an erosion and sediment control plan for city approval before any building or grading permit is issued.
Hawthorne Construction Erosion and Sediment Control
Significant RestrictionsHawthorne Code § 8.50.150
A. Stormwater run-off containing sediment, construction materials or other pollutants from the construction site and any adjacent staging, storage or parking areas shall be reduced to the maximum extent practicable. ... 2. Structural controls such as sediment barriers, plastic sheeting, detention ponds, hydromulch, storm drain inlet protection, fiber rolls, chemical treatment, filters, berms, a...
Flood Zones
Hawthorne requires a development permit for any construction in a flood-prone area identified on FEMA's Flood Insurance Rate Maps for Los Angeles County. The director of building and safety administers the program and reviews every application before ground is disturbed.
Hawthorne Floodplain Development Permit Rules
Some RestrictionsHawthorne Code § 15.48.100
A development permit shall be obtained for all proposed construction or other development in the community, including the placement of manufactured homes, so that it may be determined whether such construction or other development is within flood-prone areas.
Flood Elevation Requirements
Any new construction or substantial improvement, including manufactured homes, sited in a Hawthorne flood-prone area must be anchored against flotation and lateral movement and built with flood-damage-resistant materials and protected utility equipment, under Hawthorne Code § 15.48.130 of the city's floodplain management chapter.
Hawthorne Flood-Prone Area Construction Standards
Some RestrictionsHawthorne Code § 15.48.130
If a proposed building site is in a flood-prone area, all new construction and substantial improvements, including manufactured homes, shall: A. Be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. B. Be constructed: 1. With materials and utilit...
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