Honolulu County regulates grading and drainage under ROH Chapter 18A, requiring permits, bonds, and inspections for land alteration across Oahu to protect slopes, streams, and downstream properties.
Chapter 18A is Oahu's grading and drainage code. Article 2 covers permits, bonds, and inspections, with Sec. 18A-2.2 setting grading permit application requirements and Sec. 18A-2.4A specifying penalties for grading without a permit. Article 3 regulates grading, grubbing, and stockpiling, including cut and fill slope ratios, drainage diversion, and revegetation. DPP reviews plans and can require hydrology reports for projects that may affect downstream drainage across the island, from Mililani ridge lots to coastal Hauula parcels. Grading permits typically require posted security bonds for site stabilization.
Grading without a permit can trigger Sec. 18A-2.4A penalties, including doubled permit fees, stop-work orders, civil fines up to $1,000 per day, and restoration requirements for disturbed areas.
Honolulu, HI
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Side-by-side rule comparisons with other cities in Honolulu County.
See how other cities in Honolulu County handle grading & drainage.
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