Cupertino, CA Environmental Rules: Erosion Control (2026)

08 of the Municipal Code, Excavations, Grading and Retaining Walls, states its purpose is to preserve and enhance water quality by controlling surface runoff, erosion and sedimentation. 060, alongside the grading plan, work schedule and soils report. 110 spells out what that Interim Plan must contain: the applicant must calculate maximum surface runoff from the site using a ten-year design storm and the City's intensity curves from the master storm drain plan, then describe the sediment-retention measures such as berms and sediment detention basins with their maintenance schedule, the surface runoff and erosion control measures including mulching and diverters, dikes and drains, and the vegetative measures including seeding methods and preexisting vegetation to be preserved, each with its own maintenance schedule.

Every measure listed must be depicted on a site map, and the applicant must submit a cost estimate for implementing and maintaining the interim measures in a form the Director accepts. 150 requires the permittee to post a bond covering both grading erosion control and any corrective work needed to eliminate geological hazards or conditions likely to pollute a watercourse with sediment, in an amount at least equal to the approved estimated cost of that work. 140 requires a master work schedule that includes the proposed timing for installing all interim erosion and sediment control measures, tying the plan to an enforceable construction sequence rather than a one-time filing.