Environmental Rules in Hawaii County, HI (2026)
4 rules for unincorporated Hawaii County, Hawaii.
Verified from official government sources
Stormwater Management
Hawaii County regulates drainage facilities under HCC Chapter 27, Floodplain Management. Any new construction or substantial improvement next to a drainage facility, even outside mapped flood hazard zones, needs Department of Public Works review, and nobody may modify, line, or alter a drainage facility without director approval.
Stormwater and Drainage Facility Rules, Big Island
Some RestrictionsHawai'i County Code § 27-25
Section 27-25. Standards for improvements adjacent to drainage facilities. New construction, improvements to repetitive loss structures, and substantial improvements proposed adjacent to drainage facilities outside of the special flood hazard areas identified on the Flood Insurance Rate Maps shall be subject to review and approval of the director of public works. (a) Upon request by the directo...
Erosion Control
Hawaii County requires a grading permit before any excavation or fill, a separate grubbing permit before clearing vegetation, and a stockpiling permit before storing more than 500 cubic yards of material. Section 10-9 bars starting any of the three without a permit from the department of public works, and section 10-8 fines violators up to $500 per day of noncompliance.
Grading and Erosion Control Permits, Hawaii County
Some RestrictionsHawaii County Code § 10-9
Except as excluded in section 10-3: (1) No grading work shall be commenced or performed without a grading permit. (2) No grubbing work shall be commenced or performed without a grubbing permit except where grubbing concerns land for which a grading permit has been issued. (3) No stockpiling work shall be commenced or performed without a stockpiling permit. No grading, grubbing, or stockpiling p...
Flood Zones
New construction and substantial improvements in Hawaii County's special flood hazard areas must be elevated at least one foot above the base flood elevation, or floodproofed and certified by a licensed engineer or architect. Building in a floodway without engineering certification is prohibited outright.
Flood Zone Building Rules on the Big Island
Significant RestrictionsHawai'i County Code § 27-18(d)(1)
(d) Elevation and floodproofing. (1) Within Zones AE and AH: (A) For residential new construction, improvements to repetitive loss structures, and substantial improvements, the lowest floor shall be elevated to or above the base flood elevation plus a freeboard of at least one foot. (B) For nonresidential new construction, improvements to repetitive loss structures, and substantial improvements...
Flood Elevation Requirements
Hawai'i County's floodplain chapter sets a hard number for anyone building in a mapped special flood hazard area: Section 27-18(d)(1)(A) requires the lowest floor of new residential construction in Zones AE and AH to sit at or above the base flood elevation plus at least one foot of freeboard. Nonresidential buildings must be elevated or floodproofed to the same height.
Flood Elevation Rules on Hawaii Island
Some RestrictionsHawaii County Code § 27-18(d)(1)(A)
Within Zones AE and AH: (A) For residential new construction, improvements to repetitive loss structures, and substantial improvements, the lowest floor shall be elevated to or above the base flood elevation plus a freeboard of at least one foot.
All Hawaii County ordinances
See every category we cover for Hawaii County: parking, noise, fences, fires, animals, pools, and more.
Hawaii County Ordinance Hub →