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Grading and erosion control in Mill Valley

Mill Valley's own rules on grading and erosion control, with the code text for every value.

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Each rule below links to the section of the Mill Valley Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What Mill Valley's code says

Mill Valley code What Mill Valley's code adds
When a grading permit is needed
  • A permit is needed to grade or fill more than 50 cubic yards.
    Applies: No permit is needed where natural and finished slopes are under 10%.
    § 14.32.030 · code text
    Where volume of material to be graded or filled does not exceed 50 cubic yards.
Grading without a permit
  • No permit if graded or filled volume at most 50 cubic yards, or natural and finished slopes are under 10%.
    § 14.32.030 · code text
    A. Where volume of material to be graded or filled does not exceed 50 cubic yards. B. Where natural and finished slopes are less than 10%.
  • Excavations for basements, footings or piers of permitted structures; wells or utilities; exploratory digs directed by soils engineers or geologists.
    § 14.32.030 · code text
    Excavations for basements and footings, or piers for a building, retaining wall or other structure authorized by a valid building permit. D. Excavations for wells or utilities. E. Exploratory excavations prepared under direction of soils engineers or engineering geologists.
Rainy-season limits
  • No grading October 15–April 15 without a rainy season grading permit; erosion controls in place before October 15.
    § 14.32.080 · code text
    No grading activity shall take place during the rainy season (October 15th to April 15th) unless a rainy season grading permit has first been obtained from the Director of Public Works.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What are the grading rules in Mill Valley?

Mill Valley's code: A permit is needed to grade or fill more than 50 cubic yards. (No permit is needed where natural and finished slopes are under 10%.) (§ 14.32.030); No grading October 15–April 15 without a rainy season grading permit; erosion controls in place before October 15. (§ 14.32.080).

General information, not legal advice.

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