Off-Grid Living in Clark County, Idaho
Clark County runs its own zoning and building-permit system rather than deferring fully to the state, and it appears to treat RVs/tiny homes as temporary construction-related housing rather than permanent dwellings. Septic, greywater, and well matters are handled by Eastern Idaho Public Health and the state IDWR, not the county itself.
Is it legal to live off-grid in Clark County, Idaho?
There is no outright ban on living off-grid in Clark County, Idaho - it is legal but regulated. Zoning and land use are set locally and vary by area, putting a cabin, tiny home, or RV on raw land is restricted, and building permits are restricted. Plan around septic/wastewater (generally allowed) and disconnecting from utilities (not clearly documented online, so confirm it locally). Because these rules are set locally, confirm the specifics with Clark County before you buy land or build.
The verdict for Clark County
- Zoning: Varies locally
- Dwellings, tiny homes: Restricted
- Building permits: Restricted
- Septic: Generally allowed
- Greywater reuse: Restricted
- Rainwater harvesting: Unclear - verify
- Private wells: Generally allowed
- Living disconnected from utilities: Unclear - verify
Clark County at a glance
Who to call in Clark County
- Zoning Clark County Planning & Zoning Department 208-374-5271
- Building permits Clark County Planning & Zoning / Building Department 208-374-5304
- Septic and health Eastern Idaho Public Health, Environmental Health
- Wells and water Idaho Department of Water Resources, Wells Program
Offices named on official pages during research. Phone numbers appear only when the official page showed one; confirm hours and jurisdiction before you drive out.
Clark County, Idaho is about as rural as Idaho gets, and that shows in how it handles off-grid living. Unlike some counties that leave everything to the state, Clark County actually has its own Comprehensive Plan and zoning ordinance, run by the county Planning & Zoning Department. So you can't assume "no zoning" here, and you can't skip county involvement.
Zoning: The county's Planning & Zoning Department handles rezones, conditional use permits, variances, and lot splits. If you want a zoning change, county rules require you to file at least thirty days ahead of a Commission meeting, with a public hearing to follow per Idaho Code. Bottom line: raw land here isn't zoning-free, check with the county before you assume you can do anything you want with a parcel.
Dwellings, tiny homes, RVs: This is one area where Clark County is stricter than people expect. I could not find any provision allowing an RV or tiny home as a permanent, standalone residence. What I did find is a temporary site permit for RVs used as housing while you're building, good for a year with a possible one-year extension, but tied to an active residential building permit and requiring removal within 30 days of the home's completion. If living long-term in an RV or tiny home is your plan, that's a conversation to have directly with the county before you buy land.
Building codes: Clark County enforces the International Building Code through a contracted inspector, coordinated by the Planning & Zoning Administrator. That means a real building permit process, not just a self-certification.
Septic: The county itself doesn't run septic permitting, that job belongs to Eastern Idaho Public Health, one of Idaho's seven regional health districts, operating under an MOU with the state Department of Environmental Quality. Composting toilets and other alternatives fall under this same onsite wastewater framework (IDAPA 58.01.03), so check with the health district on what's acceptable.
Greywater: No county-specific ordinance turned up. It appears greywater is folded into the same state onsite-wastewater rules that govern septic, with Eastern Idaho Public Health as the local contact.
Rainwater harvesting: I couldn't find a county ordinance or state page speaking specifically to residential rooftop rainwater collection in Clark County. Treat this as unresolved and ask the county or state before relying on it.
Wells: This is entirely a state matter through the Idaho Department of Water Resources. You need a drilling permit before a licensed driller starts work. Domestic wells generally don't need separate water-right approval up front, but irrigation, commercial, or municipal wells do. A 2025 law (Senate Bill 1083a) changed how domestic water rights and shared wells work starting July 1, 2025, so it's worth confirming current requirements with IDWR directly.
Utility disconnection: There's no standalone Clark County rule saying off-grid living is fine or forbidden. It's governed indirectly, through the same zoning and building permit process described above.
My honest read: Clark County has more active local oversight than a lot of rural Idaho counties, especially on building and RV/tiny-home dwelling use. Confirm specifics with the offices below before committing to a plan.
Clark County in numbers
- Worst-month sun
- 1.9 peak hours/day (4.4 annual average)
- Heating degree days
- 5,169
- Precipitation / snow
- 12.31 in / 10.5 in a year
- Frost-free season
- 04-12 to 10-23
- Elevation
- 732 ft
- Fire station
- Lewiston Fire Department Station 4 · 2.8 mi
- Supermarket
- WinCo Foods · 3.9 mi
- Hardware
- Early Bird Supply · 3.0 mi
- Hospital
- Tri-State Memorial Hospital · 3.1 mi
Open the full site report for this spot →
30-year climate normals for the nearest ZIP and distances from the town center; a specific parcel will differ. Run the site report on an address for its own numbers.
Planning a build in Clark County
The rules above decide what you may build. The numbers below decide what you will have to build, and they come from this place rather than from a national average.
Solar: size for the worst month, not the average
Clark County averages 4.4 peak sun hours a day across the year, but its worst month averages 1.9. That is a drop of about 56 percent. An array sized on the annual figure will therefore come up short in the worst month by roughly that much, in the season when lights, pumps, and heating fans all run hardest.
Put another way, meeting the same daily load in the worst month here takes about 2.3 times the array that the annual average implies, or a generator and the fuel budget to run it. Neither is wrong; what is wrong is discovering the gap in the first winter. The solar calculator runs this arithmetic against your own load list, and lesson four covers building that list before buying panels.
Heat: 5,169 heating degree days
That is a cold-climate heating season, where the fuel supply is a year-round job and a second heat source earns its keep. Heating demand at this level dwarfs everything electrical in the house, which is why almost nobody here heats with electricity from a battery bank.
As a rough order of magnitude, a small, reasonably insulated cabin heated mainly with wood in a climate like this tends to burn in the region of 4.3 cords a season, with the real figure swinging widely on insulation, house size, and how you burn. Treat that as a bracket for planning your woodshed rather than a promise, split and stack a season ahead, and check with a moisture meter before burning. The firewood calculator and heat-loss calculator narrow it down from your own building.
Growing season: about 194 frost-free days
Average last frost falls around 04-12 and average first frost around 10-23, which leaves roughly 194 days between them. That figure decides what can be grown outdoors without protection, whether a season extension structure is worth building, and how much of the year food storage has to cover. Averages also hide the frost that arrives two weeks early, so plan the garden on the short end. The garden calculator and food storage calculator work from this number.
Water: what the roof would actually catch
Clark County receives about 12.3 inches of precipitation a year. A 1,000 square foot roof here would shed on the order of 6,519 gallons a year at a realistic 85 percent collection efficiency, before any losses to first-flush diversion, evaporation, or overflow in a heavy storm.
The annual total is the easy part. What sizes a cistern is the longest dry stretch, because catchment is seasonal almost everywhere and a tank that covers the average year can still run empty in August. Check the local rules too: rainwater harvesting is regulated in some states even where it is broadly allowed. The rainwater calculator works from your own roof and rainfall pattern, and lesson three covers why water is chosen before power.
Distance is part of the plan
Measured straight line from the center of Clark County: the nearest fire station is about 2.8 miles away (Lewiston Fire Department Station 4), the nearest hospital is about 3.1 miles away (Tri-State Memorial Hospital), the nearest supermarket is about 3.9 miles away (WinCo Foods). Road miles will be longer, and in winter longer again.
The fire distance is worth noting before you buy rather than at renewal: insurers commonly rate rural property partly on how far it is from a responding station and from a water source, and some decline off-grid or owner-built structures outright. Ask an agent who writes rural policies what they would need to see, while the answer can still change what you build. Lesson eleven covers the insurance and financing side.
The hospital distance sets what your first aid kit and your medical plan have to cover in the gap, and it is the number to think about before anyone in the household depends on refrigerated medication or mains-powered equipment.
Confirming this for your own parcel
On this page 3 of the eight topics are recorded as unclear or as varying within Clark County: zoning, rainwater harvesting, mandatory utility connection. Those are the calls to make first, because they are the ones where a general answer cannot be trusted for a specific parcel. Ask for the answer in writing where the office will give it, and note the name and the date where it will not.
Where a topic is recorded as settled here (what counts as a dwelling, building permits and codes, septic and sewage, greywater, wells and water rights), the source is cited further down this page. Sources go stale, ordinances get amended, and this site logs corrections publicly rather than editing them away, so if you find something here that no longer matches the county, the corrections page is how to say so.
Before any of those calls, walk the parcel with the land walk checklist and take the questions for the county with you. The parcel check pulls flood, wetland, slope, and access data for a specific parcel and shows its sources, which is a good way to arrive at the office with the questions already framed. Lesson two is the wider version of this list.
Sources
Primary sources (statutes, agencies, municipal documents)
- JULY 2015 Clark County Planning and Zoning Department 2015 www.clark-co.id.gov
- Pursuant to Idaho Code Section 67-6509 - Clark County, ID www.clark-co.id.gov
- Planning & Zoning | Clark County, ID www.clark-co.id.gov
- Clark County Zoning (Idaho) www.countyzoning.org
- Clark County Planning and Zoning Department www.clark-co.id.gov
- Planning / Zoning clarkforkidaho.gov
- Clark County Building Department Building Permit Application www.clark-co.id.gov
- Plan Review and Permits - DOPL (idaho.gov) dopl.idaho.gov
- Permits and Inspections - DOPL (idaho.gov) dopl.idaho.gov
- Septic & Land Development - Southwest District Health swdh.id.gov
- Septic, Subdivisions & Water - Central District Health - Idaho.gov cdh.idaho.gov
- Septic and Septage - Idaho Department of Environmental Quality www.deq.idaho.gov
- Septic | Eastern Idaho Public Health eiph.id.gov
- Septic Systems Search - Central District Health - Idaho.gov cdh.idaho.gov
- Water - Southwest District Health swdh.id.gov
- Wells Overview | Idaho Department of Water Resources idwr.idaho.gov
- Domestic Exemption | Idaho Department of Water Resources idwr.idaho.gov
- Well Driller Licensing Program | Idaho Department of Water Resources idwr.idaho.gov
- Water Right Forms | Idaho Department of Water Resources idwr.idaho.gov
- Idaho Department of Water Resources - Idaho.gov research.idwr.idaho.gov
- Active Districts | Idaho Department of Water Resources idwr.idaho.gov
- npdes permit clarkia water and sewer district idaho 19january2021snapshot.epa.gov
Only government, statute, municipal, university, and regional-planning sources are listed. Pages used to find an issue but not to substantiate it are not cited. See how this database is researched.
Live here? Help keep Clark County accurate.
Residents, landowners, builders, and town officials: confirm what is right or tell me what is wrong. Every note is checked before it appears. Two minutes, no account.
FAQ
Common questions about off-grid living in Clark County
Can I live full-time in an RV or tiny home on my land in Clark County?
Based on the research, that doesn't look allowed as a permanent setup. The county only appears to permit RVs as temporary housing tied to an active building permit, with removal required once your home is finished. Check directly with Clark County Planning & Zoning before making plans.
Who do I contact for a septic permit in Clark County?
Not the county itself. Septic permitting here goes through Eastern Idaho Public Health, the regional state health district that administers Idaho's onsite wastewater rules.
Do I need a permit to drill a well?
Yes, from the Idaho Department of Water Resources, not the county. Domestic wells generally skip the water-rights step other well types need, but confirm current rules since a 2025 law changed some domestic and shared-well provisions.
Is off-grid living explicitly legal in Clark County?
There's no ordinance that spells this out one way or the other. It's shaped indirectly by the county's zoning and building permit requirements, so the practical answer depends on how you build and where.
New here, or not sure where this fits? Start here walks through the whole thing in order.
