Haw. Rev. Stat. § 205-5

(a) Except as herein provided, the powers granted to counties under section 46-4 shall govern the zoning within the districts, other than in conservation districts. Conservation districts shall be governed by the department of land and natural resources pursuant to chapter 183C.

(b) Within agricultural districts, uses compatible to the activities described in section 205‑2 as determined by the commission shall be permitted; provided that accessory agricultural uses and services described in sections 205‑2 and 205‑4.5 may be further defined by each county by zoning ordinance. Each county shall adopt ordinances setting forth procedures and requirements, including provisions for enforcement, penalties, and administrative oversight, for the review and permitting of agricultural tourism uses and activities as an accessory use on a working farm, or farming operation as defined in section 165‑2. Ordinances shall include but not be limited to:

(1) Requirements for access to a farm, including road width, road surface, and parking;

(2) Requirements and restrictions for accessory facilities connected with the farming operation, including gift shops and restaurants;

(3) Activities that may be offered by the farming operation for visitors;

(4) Days and hours of operation; and

(5) Automatic termination of the accessory use upon the cessation of the farming operation.

Each county may require an environmental assessment under chapter 343 as a condition to any agricultural tourism use and activity. Other uses may be allowed by special permits issued pursuant to this chapter. The minimum lot size in agricultural districts shall be determined by each county by zoning ordinance, subdivision ordinance, or other lawful means; provided that the minimum lot size for any agricultural use shall not be less than one acre, except as provided herein. If the county finds that unreasonable economic hardship to the owner or lessee of land cannot otherwise be prevented or where land utilization is improved, the county may allow lot sizes of less than the minimum lot size as specified by law for lots created by a consolidation of existing lots within an agricultural district and the resubdivision thereof; provided that the consolidation and resubdivision do not result in an increase in the number of lots over the number existing prior to consolidation; and provided further that in no event shall a lot which is equal to or exceeds the minimum lot size of one acre be less than that minimum after the consolidation and resubdivision action. The county may also allow lot sizes of less than the minimum lot size as specified by law for lots created or used for plantation community subdivisions as defined in section 205‑4.5(a)(12), for public, private, and quasi-public utility purposes, and for lots resulting from the subdivision of abandoned roadways and railroad easements.

(c) Unless authorized by special permit issued pursuant to this chapter, only the following uses shall be permitted within rural districts:

(1) Low density residential uses;

(2) Agricultural uses;

(3) Golf courses, golf driving ranges, and golf-related facilities;

(4) Public, quasi-public, and public utility facilities; and

(5) Geothermal resources exploration and geothermal resources development, as defined under section 182-1.

In addition, the minimum lot size for any low density residential use shall be one-half acre and there shall be but one dwelling house per one-half acre, except as provided for in section 205-2. [L 1963, c 205, pt of §2; Supp, §98H-5; HRS §205-5; am L 1969, c 232, §1; am L 1977, c 140, §2; am L 1978, c 165, §1; am L 1991, c 281, §4; am L 1994, c 270, §2; am L 2005, c 205, §4; am L 2006, c 237, §5 and c 250, §3; am L 2012, c 97, §8 and c 329, §5]