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Columbia County Unincorporated
City Zoning Code

CHAPTER 18

35 AGRICULTURAL RESIDENTIAL ZONES 1

§ 18.35.010 Purpose.

The purpose of this chapter, providing for the establishment of AR zones, is as follows:
A. 
To provide for the orderly transition from rural to urban land use.
B. 
To provide for the logical extension of utilities and urban facilities and services.
C. 
To ensure compatibility between limited agricultural uses and residential development.
D. 
To ensure compatibility between city and county development standards for urban and suburban densities.
Subject
Zone District
AR-1
AR-2
Maximum building height
35 feet
35 feet
Minimum parcel size
7,200 square feet (w/public water and sewer)
10 acres/du max. density
1 acre (w/public water)
5 acres (outside of UGA)
Setbacks
See Note 2(h) and Note 3
Front
County road
15 feet + 1/2 ROW from centerline
State highway
Outside WSDOT safety zone or 10 feet from ROW, whichever is greater
Private road
10 feet from ROW
Side
5-foot minimum
10 feet
Rear
5 feet
10 feet
Minimum road frontage or lot width
See Note 1
>5 acres: 330 feet
5 acres or less: 180 feet
Signage
2 non-illuminated signs, 6 square feet each
1 non-illuminated sign, 32 square feet max.
Note:
Signs located on Highway 12 are subject to Highways Control Act Chapter 468-66 WAC and Scenic Vistas Act Chapter 47.42 RCW as referenced in WSDOT Highway Advertising Control Guidelines.
Notes:
1.
AR-1 zone:
a.
For 7,200-square-foot lots, the minimum lot width shall be 60 feet. The minimum lot depth shall be 100 feet.
b.
For one-acre lots, the minimum lot width shall be 120 feet. The minimum lot depth shall be 260 feet unless a different dimension is required.
c.
Subdivisions or short plats having lot size of one acre or larger shall be designed to provide lot dimensions and building siting (building setbacks) which will accommodate future lot division in compliance with urban lot standards.
d.
Outside of the boundary of an urban growth area any subdivision creating lots of less than five net acres in size shall only be approved and created as part of a planned unit development subject to the PUD process per Chapter 18.70 CCC, Planned Unit Development (PUD) Overlay Zone.
2.
AR-2 zone:
a.
Subdivisions.
i.
Density shall be calculated solely on the parcel owned by applicant and shall not factor in surrounding parcels. A minimum of 20 acres is required to divide one parcel.
ii.
Land divisions shall include a statement on the face of the recorded land division plat stating that the acreage shall not be used more than once for determining the allowable number of units. The applicant shall state on the face of the recorded land division plat the specific acreage used for determining the proposed new lots.
b.
Water Supply.
i.
All development in an AR-2 zone shall comply with Chapter 246-291 WAC (Rules and Regulations of the State Board of Health Regarding Public Water System) and Chapter 15.15 CCC.
ii.
Water supply mains for single-family dwellings shall be at least one inch in diameter. Garden hose outlets shall be frost-free and shall be at least 10 feet, but not more than 50 feet, from the building to permit hose stream protection for all sides of the building and the roof.
c.
Structural Considerations.
i.
All construction shall conform to the Washington State Uniform Building Code or subsequently adopted building codes and/or the Columbia County building code and permit ordinance, Chapters 15.05 and 15.10 CCC.
ii.
Roofs and exteriors of buildings shall be of fire-resistant materials, shingles, sheets of iron, aluminum, or fire retardant-treated wood shingles or shakes. Said roofs and exteriors shall be of a color that will blend with the natural environment of the area. No construction material that will cause glare shall be permitted.
iii.
Screening, or equivalent material, of roof, attic, and crawlspace openings shall be required.
iv.
Any chimney or stovepipe connected to a device burning solid or liquid fuel shall be equipped with a screen over the outlet. Screens shall be constructed of nonflammable material with openings of not more than one-half inch in size.
d.
Vegetative Clearance.
i.
A fire break of not less than 30 feet shall be maintained around all buildings and structures. This fire break may contain ornamental shrubbery, trees, or similar plants used as a ground cover, provided they do not provide a means of rapidly transmitting fire from native growth to buildings or structures. Wider breaks may be required on slopes exceeding 30 percent.
ii.
No portion of a tree or any other vegetation shall extend to within 15 feet of the outlet of a stovepipe or chimney.
e.
Outdoor Fireplaces and Barbecues.
i.
Permanent outdoor fireplaces and barbecues shall be equipped with a screen over the outlet and a method of controlling in-draft. Screens shall be constructed of nonflammable material with openings of not more than one-half inch in size.
ii.
No portion of a tree or any other vegetation shall extend to within 15 feet of the outlet of a stovepipe or chimney.
iii.
An area of five feet around permanent outdoor fireplaces and barbecues shall be cleared of flammable material including bark and mulch.
f.
Sewage Disposal.
i.
All sewage disposal systems shall be approved by the Columbia County environmental health official.
ii.
The director of environmental health may require that a test hole be dug to the minimum depth of six feet in order to analyze the type and composition of the soil in the area of a proposed drain field.
iii.
No subsurface sewage effluent discharge shall be allowed in floodplains or floodways.
iv.
Chapter 246-272A WAC (Rules and Regulations of the State Board of Health of On-Site Sewage Disposal Systems), as adopted by Columbia County, shall be complied with.
v.
Incinerator toilets and sealed pit toilets are allowed upon approval of the environmental health official.
vi.
Rustic development will be allowed only when soil conditions or other conditions prohibit the use of more conventional-type sewage systems.
g.
Solid Waste. All solid waste (garbage) shall be transferred to the Columbia County transfer station or other approved disposal site.
h.
Structures housing domestic animals or any use that produces offensive noise, vibration, smoke, dust, odors, heat or glare shall maintain 50- foot front, rear and side yard setbacks.
3.
All approaches, roads and sight triangles shall meet the Standards for Design and Construction of Roads in Un-Incorporated Columbia County guidelines as approved by the County Engineer.
(Ord. 90-02 § 11; Ord. 95-01 § 11; Ord. 2015-02 § 2; Ord. 2017-03 (Exh. E); Ord. 2020-02 § 2 (Exh. G); Ord. 2022-02; Ord. 2025-03, 9/15/2025)