HCC §27-22
Rules for building in floodways
Read the official text at hawaiicounty.gov ↗This section sets rules for any work or new development in a floodway, which is a dangerous area that carries floodwater. You cannot build or add fill unless a licensed engineer or architect proves it won't raise flood levels. Some non-building uses like farms or parks are reviewed case by case.
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The ordinance, as written (Hawaiʻi County) — Standards for floodways
A copy, taken August 21, 2026. The version published by Hawaiʻi County is the one that governs, and it may have changed since. Check it before relying on anything here.
The floodway identified on the Flood Insurance Rate Maps and located within areas of special flood hazard is the watercourse reserved to discharge the base flood. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply: (a) Encroachments, including fill, new construction, improvements to repetitive loss structures, substantial improvement, and other new development shall be prohibited unless certification and supporting data is provided by a licensed professional engineer or architect demonstrating that the encroachment will not cause any increase in base flood elevations during the occurrence of the base flood discharge. (b) If an encroachment within a floodway is allowed under the conditions of paragraph 27-22(a), all new construction, improvements to repetitive loss structures, substantial improvement and other proposed new development shall comply with all applicable flood hazard reduction provisions established in this chapter. FLOODPLAIN MANAGEMENT § 27-22 (c) The following uses, not involving fill, shall be evaluated on a case-by-case basis to establish that the use does not cause any increase in base flood elevations: (1) Public and private outdoor nonstructural recreational facilities, lawn, garden, and play areas; (2) Agricultural uses, including farm, grazing, pasture, and outdoor plant nurseries; and (3) Drainage improvements, such as channels and stream crossings. (1993, ord 93-78, sec 3; am 2007, ord 07-169, sec 13.)27-22
Published by the County of Hawaiʻi Office of the County Clerk.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.