Off-grid site report
Clark County, IL
39.2912, -87.9868 · 640 ft elevationRead this before you act on anything below. This is my researched starting point for Clark County, IL, 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 rulesClark County, IL
Zoning & raw-land occupancy
Unclear - verifyNo official Clark County zoning ordinance could be found; unincorporated land may or may not be covered by county zoning, and land inside a municipality like Marshall follows that town's own ordinances instead. Not confirmed either way for unincorporated areas. source
Dwellings, tiny homes & RVs
Unclear - verifyNo county rule on minimum dwelling size, tiny homes, or RV residency was found. The Supervisor of Assessments does track and tax mobile/manufactured homes placed outside parks, but that's a tax registration, not a zoning approval. source
Building permits & codes
Unclear - verifyNo Clark County building department or permit ordinance was found. Illinois has a statewide building code baseline, but how the county applies it outside towns is not confirmed. source
Septic & composting toilets
Generally allowedThe Clark County Health Department permits private sewage (septic) systems under Illinois state code, requiring a soil evaluation and installation by a licensed contractor or the homeowner; aerobic systems need a service contract. source
Greywater reuse
Unclear - verifyNo specific Clark County or state rule on residential greywater reuse was found. It likely falls under the health department's private sewage review, but that is not explicitly confirmed.
Rainwater harvesting
Unclear - verifyNo Clark County or Illinois state source specifically addressing residential rainwater harvesting was found.
Private wells & water rights
Generally allowedThe Clark County Health Department issues private well permits under the state well code, and only Illinois-licensed well contractors may construct wells.
Living disconnected from utilities
Unclear - verifyNo county ordinance or health department statement addresses living disconnected from grid electricity or municipal water/sewer; this likely ties back to septic and well permitting but isn't explicitly confirmed.
Sun30-year normals
- Peak-sun hours, annual average
- 4.8 hrs/day
- Worst month (sizes an off-grid array)
- 2.8 hrs/day
- Yearly output per 1 kW of panels
- 1,364 kWh
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Weather1991-2020
- Precipitation
- 43 in/yr
- Snowfall
- 17 in/yr
- Heating degree days
- 5,153 (moderate)
- Frost-free season
- Apr 17 to Oct 20
How far help isstraight-line
- Hospital
Sarah Bush Lincoln Health Center - 20.4 mi
- Fire station
Westfield Fire Protection District - 11.4 mi
- Hardware store
Under His Wings DIY - 0.7 mi
- Grocery
Walmart Supercenter - 16.2 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 62420).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Clark County, IL?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 22, 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.