Environmental Rules in Island County, WA (2026)
5 rules for unincorporated Island County, Washington.
Verified from official government sources
Stormwater Management
Island County's stormwater code regulates drainage from nearly every development in the unincorporated area, from single-family lots to major subdivisions, requiring a drainage plan, mitigation for downstream impacts, and setbacks between structures and drainage facilities before Public Works signs off on a building or grading permit.
Stormwater and Drainage Requirements, Island County
Some RestrictionsIsland County Code § 11.03.200
A.Stormwater entry and exit. If drainage patterns currently exist on the site, drainage facilities must be designed so that stormwater enters and exits the site at the existing location(s) of entry and exit.B.Mitigation. Mitigation must be provided for drainage impacts resulting from changes in the flow rate and quality of stormwater runoff, and in the case of a critical drainage area from chan...
Erosion Control
Anyone grading or cutting a lot in unincorporated Island County under a Title XI clearing and grading permit must stabilize every cut and fill slope against erosion, using planting, hydroseeding, mulching, check dams, riprap, or silt fences before the county signs off on final project approval.
Erosion Control During Grading, Island County
Some RestrictionsIsland County Code § 11.02.330
A.The faces of cut and fill slopes shall be prepared and maintained to control against erosion. This control may consist of effective planting, hydroseeding, or mulching. The protection for the slopes shall be installed as soon as practicable and prior to calling for/or requesting final project approval. Where cut slopes are not subject to erosion due to the erosion-resistant character of the m...
Flood Zones
In unincorporated Island County, any construction, fill, grading, or land division within a mapped area of special flood hazard requires a development permit from the Planning and Community Development Department before work begins. The Floodplain Administrator, the Planning Director, reviews applications for structures, manufactured homes, and subdivisions under the county's Flood Damage Prevention Ordinance, keyed to FEMA's March 7, 2017 flood insurance study and rate map.
Island County Flood Zone Development Permit
Some RestrictionsIsland County Code § 14.02A.040
A development permit shall be obtained before construction or development begins within any area of special flood hazard established in section 14.02A.030.B. A development permit is required for all structures including manufactured homes, and for all development, including fill and other activities within any area of special flood hazard, including subdivision or other division of land.
Boat Dock Permits
Building a private pier, dock, or float on Whidbey or Camano Island shoreline in unincorporated Island County needs a shoreline permit under the county's Shoreline Master Program, ranging from conditional-use review in most environments to permitted status only in the High Intensity designation.
Boat Dock Permits, Unincorporated Island County
Significant RestrictionsIsland County Code § 17.05A.080
TABLE 1: Shoreline Use Classification Table ... NOTES: P - Shoreline Permitted use X - Shoreline prohibited use C - Shoreline conditional use ... SHORELINE ... DESIGNATIONS Aquatic Natural Rural Conservancy Urban Conservancy Shoreline Residential High Intensity ... Boating and Related Facilities ... Private piers, docks, an floats C/P 13 C C C C/P 1 P
Flood Elevation Requirements
Island County requires new and substantially improved buildings in a mapped A zone to elevate the lowest floor at least one foot above the base flood elevation, and coastal V-zone structures at least one foot above base flood level on pilings, under Island County Code Section 14.02A.050. Nonresidential buildings may instead meet the ASCE 24 standard if it produces a higher elevation.
Island County Base Flood Elevation Rule
Some RestrictionsIsland County Code § 14.02A.050
a.In all A zones where the base flood elevation has been determined or can be reasonably obtained, new construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above the base flood elevation. ... a.In A zones where the base flood elevation has been determined or can reasonably be obtained, new construction a...
All Island County ordinances
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