Montebello, CA Environmental Rules: Erosion Control (2026)

Chapter 15.48, Grading, treats November 15th through April 15th as the period during which heavy rainfall normally occurs in the city under § 15.48.470(B), and any grading work that was authorized earlier but continues into that window must be protected with temporary erosion control devices. The plans for those devices must go to the engineering department for design approval no later than November 1st, and the devices themselves, including any desilting basin that discharges drainage onto city streets or natural watercourses, must be installed no later than November 15th, with the design and construction of desilting basins kept under the engineering department's direct control.

Subsection A separately bars placing, spreading or rolling fill material whenever the city engineer considers the weather unfavorable, and once heavy rain interrupts work, fill operations cannot resume until the soils engineer's field tests show the moisture content and density again meet chapter requirements. Subsection C lets the city engineer limit or stop grading entirely during the rainy season if continuing would create a hazard to people or property. The chapter pairs the seasonal rule with a permanent planting requirement in § 15.48.480, which requires cut slopes over five feet and fill slopes over three feet to be planted with grass or groundcover, plus shrubs or trees on slopes over fifteen feet, with an approved irrigation system, before the grading bond is released.

All drainage from cut and fill slopes must run through nonerosive facilities to the nearest street, storm drain or natural watercourse under § 15.48.500, and property owners must keep every drainage and protective device in good repair under § 15.48.550.