Off-grid site report
De Witt County, IL
40.1811, -88.7862 · 755 ft elevationRead this before you act on anything below. This is my researched starting point for De Witt 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 rulesDe Witt County, IL
Zoning & raw-land occupancy
Varies locallyDe Witt County has its own zoning code, adopted in 1972, dividing the county into districts with different permitted uses and dimensional standards. Whether raw-land occupancy is allowed depends on the parcel's district; confirm with the county Planning and Zoning Department. source
Dwellings, tiny homes & RVs
Unclear - verifyNo official county page specifies minimum dwelling size, tiny-home rules, or RV-as-residence standards. This is likely covered within the zoning code's district standards; ask Planning and Zoning directly. source
Building permits & codes
Unclear - verifyNo distinct county building code or permit fee schedule was found. Illinois's new statewide building code took effect January 1, 2025, and may serve as the baseline; confirm which edition the county enforces. source
Septic & composting toilets
Generally allowedThe Illinois Department of Public Health sets statewide private sewage disposal standards, but the DeWitt-Piatt Bi-County Health Department is the local permitting and inspection authority. Surface-discharging systems additionally need an NPDES permit from Illinois EPA since January 1, 2013. source
Greywater reuse
Unclear - verifyNo county or health department page specifically addresses greywater reuse. Ask the DeWitt-Piatt Bi-County Health Department's environmental services division how greywater systems fit into their septic permitting process.
Rainwater harvesting
Unclear - verifyNo official county ordinance or guidance on residential rainwater harvesting was found, so there's no confirmed restriction or authorization at the county level.
Private wells & water rights
Generally allowedPrivate wells are permitted and actively administered locally by the DeWitt-Piatt Bi-County Health Department as the state's designated agent under the Illinois Water Well Construction Code; their annual report shows regular well and geothermal permitting activity.
Living disconnected from utilities
Unclear - verifyNo explicit county rule addresses full disconnection from electric or municipal water/sewer utilities. It would likely intersect with zoning occupancy standards and health department wastewater permitting, but no direct 'off-grid habitability' rule was found.
Sun30-year normals
- Peak-sun hours, annual average
- 4.9 hrs/day
- Worst month (sizes an off-grid array)
- 3.0 hrs/day
- Yearly output per 1 kW of panels
- 1,402 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 39 in/yr
- Snowfall
- 18 in/yr
- Heating degree days
- 6,099 (cold)
- Frost-free season
- Apr 21 to Oct 13
How far help isstraight-line
- Hospital
Warner Hospital & Health Services - 9.7 mi
- Fire station
Northern Piatt Fire Department Fire Station - 14.9 mi
- Hardware store
True Value - 11.3 mi
- Grocery
Save-A-Lot - 9.3 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 61735).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in De Witt 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.