Off-grid site report
Dewey County, SD
45.0004, -101.2343 · 2,421 ft elevationRead this before you act on anything below. This is my researched starting point for Dewey County, SD, 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 rulesDewey County, SD
Zoning & raw-land occupancy
Unclear - verifyNot confirmed whether Dewey County has adopted a zoning ordinance. State law (SDCL 11-2) lets counties adopt zoning but doesn't require it, and much of the county is tribal trust land outside county zoning authority anyway. source
Dwellings, tiny homes & RVs
Unclear - verifyNo Dewey County-specific rule on tiny homes, minimum square footage, or RV occupancy was found; this would fall under local zoning if adopted, which is unconfirmed here.
Building permits & codes
Unclear - verifyNot confirmed whether Dewey County requires building permits. South Dakota has no statewide residential building code, and many rural counties have no local permit requirement, but that hasn't been confirmed specifically for Dewey County. source
Septic & composting toilets
Generally allowedOn-site wastewater systems are regulated statewide by South Dakota under Administrative Rules Chapter 74:53:01, typically requiring a certified installer; local Dewey County administration details are not confirmed.
Greywater reuse
Unclear - verifyNo statewide DANR rule or Dewey County ordinance on greywater reuse was found. Ask the county or the state DANR Surface Water Quality Program directly.
Rainwater harvesting
Unclear - verifyNo explicit South Dakota statute or Dewey County rule on rainwater harvesting was found; small residential catchment likely falls under the state's domestic water-use exemption but this isn't explicitly confirmed. source
Private wells & water rights
Generally allowedWells are regulated statewide by South Dakota DANR under Well Construction Standards, and domestic use is generally exempt from needing a water rights permit unless it exceeds set thresholds; no Dewey County-specific addition was found. source
Living disconnected from utilities
Varies locallyNo South Dakota law or confirmed Dewey County rule prohibits disconnecting from utilities; electrical work is licensed statewide with an owner's exemption typically available for one's own residence.
Sun30-year normals
- Peak-sun hours, annual average
- 5.1 hrs/day
- Worst month (sizes an off-grid array)
- 2.9 hrs/day
- Yearly output per 1 kW of panels
- 1,465 kWh
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Weather1991-2020
- Precipitation
- 18 in/yr
- Snowfall
- 40 in/yr
- Heating degree days
- 7,650 (severe)
- Frost-free season
- May 5 to Sep 29
How far help isstraight-line
- Hospital
Cheyenne River Health Center - 0.8 mi
- Fire station
- none within range
- Hardware store
- none within range
- Grocery
Lakota Thrifty Mart - 18.3 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 57625).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Dewey County, SD?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.