Butte County, CA Building Setbacks & Zoning: Lot Coverage Limits (2026)

1(D)(8), the -BCC overlay's Watershed Protection standard, defines impervious surfaces as asphalt, concrete, structures, and any other surface that is one hundred percent impermeable to water percolation and prevents normal infiltration or causes runoff. For parcels one acre or larger within the overlay, impervious coverage cannot exceed fifteen percent of the parcel's total size. Smaller parcels are held to a fixed square-footage table instead of a percentage: up to 6,530 square feet for parcels between a half-acre and one acre, 5,800 square feet between a third-acre and a half-acre, 4,900 square feet between a quarter-acre and a third-acre, and 3,250 square feet for parcels between 5,000 square feet and a quarter-acre.

Gravel-surfaced or pervious-paved roads, patios, and driveways are excluded from the impervious count entirely. This overlay-specific limit sits within a wider set of watershed protections applying only in Butte Creek Canyon, including 100-foot vegetative buffers along perennial and intermittent streams, 200-foot septic system setbacks from those same waterways, and mandatory erosion and sediment control plans prepared by a registered civil engineer before any building permit issues. Elsewhere in the county, Butte County's separate Watershed Protection (-WP) overlay zone, covering the Firhaven Creek and Paradise and Magalia Reservoir watersheds, uses a different standard, a flat fifty percent impervious surface cap under Section 24-46(D), showing that Butte County ties its lot-coverage limits to the specific sensitive watershed rather than applying one countywide number.