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Earlier editions: 20222019

Chapter 3 — BUILDING PLANNING

R300 Site Drainage — 2025 California Residential Code

California Residential Code (Title 24, Part 2.5) · 2025 edition · updated 2026-09-26 · California

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Italicized text is a California amendment to the model code, as printed in the official publication.

Cite as: 2025 California Residential Code (Title 24, Part 2.5) § R300 · Effective January 1, 2026 · Official source: Building Standards Commission

R300.1 Storm water drainage and retention during construction.

Projects which disturb less than one acre of soil and are not part of a larger common plan of development which in total disturbs one acre or more, shall manage storm water drainage during construction in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.

Exceptions & meaning →

R300.2 Grading and paving.

Construction plans shall indicate how the site grading or drainage system will manage all surface water flows to keep water from entering buildings in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.

Exceptions & meaning →

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▸Contents — California Residential Code (Title 24, Part 2.5)
California Residential Code (Title 24, Part 2.5)

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