Environmental Rules in Honolulu County, HI (2026)

Revised Ordinances of Honolulu §§ 43-11.22(a), 43-11.23(d)

No person shall discharge any effluent other than stormwater runoff onto any public right-of-way or into any drainage facility, or both, without first obtaining a permit from the chief engineer. ... It shall be unlawful to discharge any stormwater on any public right-of-way that creates a drainage problem or causes a nuisance.

Revised Ordinances of Honolulu § 18A-1.6(a)

Notwithstanding any other law to the contrary, it is unlawful for any person to perform, participate in, or allow any development or land disturbing activity that requires a building permit, grading permit, stockpiling permit, or trenching permit without an erosion and sediment control plan that is approved the director. (b)   All development and land disturbing activities that require a buildi...

ROH § 21A-1.10

All proposed development within the general floodplain (unnumbered zone A) shall be subject to review and approval of the director. The developer shall provide information signed and stamped by a licensed engineer, to evaluate the flooding and to determine the base flood elevation, and whether the project site is located within a floodway or flood fringe area, under § 21A-1.5(d). (b)   The dire...

ROH § 21A-1.8(a)(1)

All new construction or substantial improvements of residential structures shall have the lowest floor, including basements, elevated to or above the base flood elevation. (2)   All new construction or substantial improvements of nonresidential structures shall have the lowest floor elevated to or above the base flood elevation; or together with attendant utility and sanitary facilities, be des...