Off-grid site report

Sully County, SD

44.7194, -100.1866 · 1,723 ft elevation

Read this before you act on anything below. This is my researched starting point for Sully 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 rulesSully County, SD

Zoning & raw-land occupancy

RestrictedSully County has adopted a countywide zoning ordinance (2003) and subdivision ordinance covering all unincorporated land outside Onida and Agar; raw-land occupancy without zoning review is not permitted the way it might be in an unzoned SD county. source

Dwellings, tiny homes & RVs

Unclear - verifyThe county zoning ordinance defines standard dwellings and manufactured homes, but no official text on tiny homes or RVs as permanent dwellings was found; confirm directly with Sully County Planning & Zoning. source

Building permits & codes

Varies locallySully County Planning & Zoning administers permits and fees; the state sets the 2021 IBC as the standard for jurisdictions that adopt building codes, but many rural SD areas don't enforce one, and county-specific exemptions for owner-built or farm structures aren't confirmed. source

Septic & composting toilets

Generally allowedSeptic systems must be installed by state-certified installers under South Dakota DANR rule; Sully County Planning & Zoning is the local contact, though a county-specific septic ordinance text wasn't found. source

Greywater reuse

Unclear - verifyNo Sully County or South Dakota state official text on greywater reuse was found; ask Sully County Planning & Zoning directly.

Rainwater harvesting

Unclear - verifyNo Sully County ordinance on rainwater harvesting was found; the state's domestic-use water exemption may be relevant but doesn't directly address catchment. source

Private wells & water rights

Generally allowedWells are regulated by the South Dakota DANR Water Rights Program statewide; domestic use is generally exempt from a water right permit unless it exceeds set daily/peak-rate thresholds, and licensed drillers must file completion reports. source

Living disconnected from utilities

Varies locallyNo Sully County or state law was found banning disconnection from electric, water, or sewer utilities, but well and septic approvals still function as practical requirements for occupancy.

Open the full county page with sources →

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: 1,466 kWh

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Weather1991-2020

Precipitation: 21 in/yr
Snowfall: 47 in/yr
Heating degree days: 7,797 (severe)
Frost-free season: May 8 to Sep 26

How far help isstraight-line

Hospital Avera Gettysburg Hospital: 23.5 mi
Fire station: none within range
Hardware store Lamb's Discount Supply: 6.0 mi
Grocery Don's Food Store: 5.9 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 57564).

Size a solar system Heat loss & insulation Firewood per winter Rainwater harvest Garden size Panel tilt

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.