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Walnut Creek · Building on your lot

Building on a hillside in Walnut Creek

Walnut Creek's own rules on building on a hillside, with the code text for every value.

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

What Walnut Creek's code says

Walnut Creek code What Walnut Creek's code adds
Soils or geology report
  • A current preliminary soils and geology report by a registered civil engineer and a registered geologist is required.
    Applies: H-P-D permit applications.
    § 10-2.4.1111 · code text
    A current preliminary soils and geological report prepared by a registered civil engineer and a registered geologist;
Grading and retaining walls
  • Natural open space must stay free of grading and structures, except trails, picnic areas, stables and similar amenities.
    Applies: Natural open space on an approved development plan; amenities need H-P-D permit approval.
    § 10-2.4.1109 · code text
    All areas indicated as natural open space on the approved development plan shall be undisturbed by grading, excavating, structures or otherwise except that riding trails, hiking trails, picnic areas, stables and similar amenities may be placed in natural open space pursuant to the approval of an H-P-D permit.
When hillside rules apply
  • No development on slopes of 20% or more.
    Applies: Open Space/Agriculture Lands; also within 75 vertical feet of a ridgeline.
    § 10-2.2.504 · code text
    Development on any Open Space/Agriculture Lands, as defined in this Ordinance, shall: (a) be prohibited on slopes with existing grades of twenty percent (20%) or greater

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What extra rules apply to a hillside lot in Walnut Creek?

Walnut Creek's code: No development on slopes of 20% or more. (Open Space/Agriculture Lands; also within 75 vertical feet of a ridgeline.) (§ 10-2.2.504); Natural open space must stay free of grading and structures, except trails, picnic areas, stables and similar amenities. (Natural open space on an approved development plan; amenities need H-P-D permit approval.) (§ 10-2.4.1109).

General information, not legal advice.

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Ask GoCodebook how Walnut Creek's building on a hillside rules apply to your situation and get an answer that cites the section.

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Walnut Creek Municipal Code — full text