Building on a hillside in Riverside: the local rules

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

What Riverside's code says

Riverside code What Riverside's code adds
Grading and retaining walls	Graded pad area may be at most 27,000 square feet. Applies: Hillside/arroyo grading in single-family zones, 10 to 15 percent average natural slope; the Director may adjust by up to 25 percent. § 17.28.020 · code text Ten percent to 15 percent average natural slope within the area to be graded - 27,000 square feet Graded pad area may be at most 21,000 square feet. Applies: Hillside/arroyo grading in single-family zones, 15 to 30 percent average natural slope; the Director may adjust by up to 25 percent. § 17.28.020 · code text Fifteen percent to 30 percent average natural slope within the area to be graded - 21,000 square feet Graded pad area may be at most 18,000 square feet. Applies: Hillside/arroyo grading in single-family zones, 30 to 40 percent average natural slope; the Director may adjust by up to 25 percent. § 17.28.020 · code text Thirty percent to 40 percent average natural slope within the area to be graded - 18,000 square feet No grading is allowed. Applies: Slopes over 40 percent, unless findings of exceptional or special circumstances are made. § 17.28.020 · code text No grading shall be permitted on slopes exceeding 40 percent unless findings can be made by the Planning Commission that exceptional or special circumstances as set forth in Chapter 17.32 Conditional Exceptions apply. Driveway grading may be at most 15 feet wide. Applies: Hillside/arroyo grading. § 17.28.020 · code text Shall not exceed 15 feet in width. Driveway finished grade may be at most 15 percent. Applies: Hillside/arroyo grading, unless the Fire Department and the Director approve more. § 17.28.020 · code text Shall not exceed a 15 percent finished grade unless otherwise approved by the Fire Department and Community & Economic Development Director. Cut or fill slopes of 3.9:1 or steeper may be at most 20 feet high. Applies: Hillside/arroyo grading; the Director may allow up to 25 percent more. § 17.28.020 · code text Slopes having a ratio of 3.9:1 or steeper shall not exceed 20 feet in vertical height. Cut or fill slopes of 4:1 or flatter may be up to 25 feet high. Applies: Hillside/arroyo grading; the Director may allow up to 25 percent more. § 17.28.020 · code text Slopes having a 4:1 or flatter ratio may be up to 25 feet in vertical height.
When hillside rules apply	Applies at an average natural slope of 10 percent or more. Applies: Hillside/arroyo grading rules; they also apply in the RC zone and in or next to the named arroyos. § 17.12.020 · code text The property has an average natural slope ten percent or greater.

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Frequently asked questions

What extra rules apply to a hillside lot in Riverside?

Riverside's code: Applies at an average natural slope of 10 percent or more. (Hillside/arroyo grading rules; they also apply in the RC zone and in or next to the named arroyos.) (§ 17.12.020); Graded pad area may be at most 27,000 square feet. (Hillside/arroyo grading in single-family zones, 10 to 15 percent average natural slope; the Director may adjust by up to 25 percent.) (§ 17.28.020).

Building on a hillside in Riverside

What Riverside's code says

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