Off-grid site report
Wahkiakum County, WA
46.2732, -123.4566 · 26 ft elevationRead this before you act on anything below. This is my researched starting point for Wahkiakum County, WA, not legal advice and not a guarantee. Rules change, and the deciding facts on any specific parcel (setbacks, perc results, overlay districts, deed restrictions, road frontage) live at the county or town office, not in any database. Before you buy land or build, confirm the current rules directly with the local zoning and health offices - the sources on this page tell you exactly who to call.
The local rulesWahkiakum County, WA
Zoning & raw-land occupancy
Varies locallyUnincorporated Wahkiakum County has no zoning per the county's own FAQ; the Town of Cathlamet is the exception, with its own Title 19 zoning code. Even without zoning, the county Building and Planning Department still reviews land-use, building, and septic matters countywide. source
Dwellings, tiny homes & RVs
Varies locallyPermanent residences (houses, tiny houses, RVs used full-time, manufactured homes) need a county building permit, must meet state energy code, and need approved water/septic before permitting; unplumbed recreational structures skip permitting but can't be lived in full-time. source
Building permits & codes
Generally allowedWahkiakum County Building & Planning Department administers building permits, manufactured home placement, setbacks, and related land-use permits countywide; within Cathlamet, the town's own municipal code (adopting 2018 International Building Codes and the state energy code) applies alongside county rules. source
Septic & composting toilets
RestrictedWahkiakum County Health & Human Services issues septic permits under state WAC 246-272, requiring a licensed designer's system design and mandatory test pits; composting toilets are not separately addressed in county pages found, so confirm directly with the county. source
Greywater reuse
Unclear - verifyNo Wahkiakum County-specific greywater page was found; the state WAC 246-274 baseline would apply, administered locally through county Health & Human Services, but this is not confirmed with a county-specific policy.
Rainwater harvesting
Unclear - verifyNo county-specific rainwater harvesting rule was found in official Wahkiakum sources; Washington Department of Ecology's statewide policy would be the baseline, but no county restriction or allowance is confirmed.
Private wells & water rights
Varies locallyWell water rights for Wahkiakum County are handled regionally by the Washington Department of Ecology's Water Resources Program, not the county itself, though the county's Environmental Health Department must approve a well as a water source before issuing a building permit. source
Living disconnected from utilities
RestrictedThere's no standalone off-grid ban, but the county's building permit process functionally requires approved water and septic/sewer for any permanent residence, making full utility disconnection difficult if you want a permanent home rather than a recreational structure. source
Sun30-year normals
- Peak-sun hours, annual average
- 3.6 hrs/day
- Worst month (sizes an off-grid array)
- 1.8 hrs/day
- Yearly output per 1 kW of panels
- 1,000 kWh
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Weather1991-2020
- Precipitation
- 106 in/yr
- Snowfall
- 3 in/yr
- Heating degree days
- 5,163 (moderate)
- Frost-free season
- Apr 30 to Oct 19
How far help isstraight-line
- Hospital
Columbia Memorial Hospital - 18.3 mi
- Fire station
Pudget Island Volunteer Fire Department - 7.7 mi
- Hardware store
Cathlamet Building Materials - 6.0 mi
- Grocery
Cathlamet Market & Liquor - 6.0 mi
From OpenStreetMap. Road miles will be longer, often much longer in hill country.
Plan this spot
These open with this location's real numbers already filled in (ZIP 98647).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Wahkiakum County, WA?The rules above are the jurisdiction. The land check runs the parcel itself: flood zone, soils and septic suitability, wetlands, slope, access, climate, and these verdicts, from a parcel number or coordinates.
Check a parcel →Share or save this report:New report
Sources: US Census Bureau geocoder; NLR PVWatts v8 (solar); NOAA NCEI 1991-2020 climate normals (nearest station) or Open-Meteo (ZIP-centroid) for weather; Open-Elevation; OpenStreetMap contributors. Public data retrieved Aug 21, 2026; agencies update their layers on their own schedules. Planning data, not a survey or legal advice.
New here, or not sure where this fits? Start here walks through the whole thing in order.