Day County, SD zoning map, flood zone and property lines by address
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Towns in Day County: Webster.
Flood zone by address
ParcelSheet reads FEMA's National Flood Hazard Layer at the lot: the zone, whether it is a high risk area where lenders ask for flood insurance, and the base flood elevation where FEMA lists one. FEMA's countywide study for Day County has 45 FIRM panels, the newest effective March 2024; no coastal V zones are mapped in it.
The official panel and any Letter of Map Amendment are at FEMA's Map Service Center. An elevation certificate for a Day house comes from a licensed surveyor and is often on file with the county or city building office.
Property lines
The parcel outline, parcel number and mapped size come from the South Dakota county parcel layers (each county publishes its own), so a Day lot shows the same lines the county director of equalization draws. Day County covers about 658,233 acres of land and 40,066 acres of water.
Mapped lines are approximate. The Day County director of equalization keeps the parcel record (Day County website); a licensed surveyor sets the true corners.
Zoning
Day County zones its unincorporated land, and Webster zones the land inside its limits. ParcelSheet shows the use the county director of equalization lists for the lot and links the county planning and zoning office for the district, the uses it allows and the lot size it needs.
ADU and guest houses
Under South Dakota's county planning and zoning law (South Dakota Codified Laws Chapter 11-2), local governments can allow an accessory dwelling unit on a lot with a house. Whether a Day lot can add one depends on its district; the county planning and zoning office has the rule. ParcelSheet shows the mapped lot size and the ground's slope, the first two things the question turns on.
Septic and soil
ParcelSheet reads the USDA soil survey at the lot: the soil's name, its septic absorption rating and whether it is prime farmland. Day County is soil survey area SD037, Day County, South Dakota, last updated September 2026, on Web Soil Survey.
A new or changed septic system in Day County must follow the South Dakota Department of Agriculture and Natural Resources onsite rules, installed by a state certified installer; Day County may add its own permit.
Setbacks
Setbacks in Day County come from the zoning district: the front, side and rear distances a house must keep. ParcelSheet does not draw setback lines; the county zoning office gives them for the lot's district, and Webster for land inside its limits.
Hazards that apply
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near a Day lot and the Forest Service wildfire hazard rating at it.
Questions
Is my house in a flood zone in Day County?
Type the address in the box above and ParcelSheet reads FEMA's flood zone at the lot's center. FEMA's countywide flood map for Day County has 45 panels, the newest effective March 2024. A lender or insurer uses the official FIRM panel; FEMA's Map Service Center has it.
How do I find property lines in Day County?
Open the South Dakota map, type the address, and the parcel outline from the Day County director of equalization shows on the map with its parcel number and mapped size. Mapped lines are approximate; only a licensed surveyor sets the true corners.
What is my property zoned in Day County?
Zoning in Day County is set by the county for unincorporated land and by each city (such as Webster) inside its own limits. ParcelSheet shows the use code the county director of equalization lists and links the office that sets the zoning; the planning office has the final word.
Can I build an ADU in Day County?
Under South Dakota's county planning and zoning law (South Dakota Codified Laws Chapter 11-2), counties and cities can allow an accessory dwelling unit, and each sets its own rules. In Day County ask the zoning office for the lot's district first; ParcelSheet shows the lot size as mapped so you can see the room you have.
Do I need a septic permit in Day County?
Yes. A new or changed septic system in Day County must follow the South Dakota Department of Agriculture and Natural Resources onsite rules, installed by a state certified installer; Day County may add its own permit. ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area SD037 (Day County, South Dakota).
What can I build on 5 acres in Day County?
Zoning in Day County is set by the county for unincorporated land and each city inside its own limits (such as Webster). The zoning district decides the uses, how many homes and the smallest lot it allows on 5 acres. ParcelSheet shows the lot size as mapped and the use code on the parcel record; the planning office has the district and its rules. See the Day County website.
What are the residential setbacks in Day County (2026)?
Setbacks in Day County come from the zoning code of the county, or of the city when the lot is inside city limits: the front, side and rear distances depend on the lot's district. ParcelSheet does not draw setback lines or give a number it did not read; the zoning office gives them for the district. See the Day County website.
Next to Day County: Brown County, Codington County, Grant County, Marshall County, Roberts County, Spink County.
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