South Dakota FSBO Disclosure Requirements (2026)

South Dakota's Seller Disclosure Statement covers the primary requirements. South Dakota has the highest average indoor radon levels of any US state — radon disclosure and testing is the dominant local issue. The 2011 James River flooding, Black Hills wildfire risk, and the Missouri River dam-controlled flood zones are other key South Dakota disclosure considerations.

South Dakota Disclosure Framework

SDCL §43-4-37 requires the Seller Disclosure Statement. Sellers provide before or at contract; buyers have 5 business days after receipt to rescind.

Radon in South Dakota — The Nation's Highest

South Dakota consistently reports the highest average indoor radon levels of any US state. The EPA designates the vast majority of South Dakota counties as Zone 1 (predicted average indoor levels >4 pCi/L). In some areas — particularly in the Black Hills granite zone and central SD — testing reveals extremely high levels (>10, >20 pCi/L in some cases).

Radon disclosure in South Dakota:

Radon mitigation contractors in Sioux Falls and Rapid City can install sub-slab depressurization systems for $800–$2,000. Post-mitigation levels typically drop to under 2 pCi/L.

James River Flooding (Eastern SD)

The James River drains central and northeastern South Dakota — running from near Aberdeen south through Huron, Mitchell, and Plankinton before joining the Missouri River near Yankton. The James River has an extremely flat gradient, and during wet years, flooding extends over enormous areas for extended periods.

The 2011 James River flooding was the most extensive in modern history — some James River communities experienced flooding for months (not days). If your property was in the James River corridor and was affected in 2011, the disclosure form requires comprehensive disclosure.

Black Hills Wildfire Risk

The Black Hills of western South Dakota (Custer, Lawrence, Pennington counties) have WUI wildfire risk from the ponderosa pine forests. Key fire events:

The South Dakota disclosure form covers known environmental and condition issues. Properties in documented WUI zones near ponderosa pine forest should note wildfire risk.

Missouri River Reservoir Properties

Several major Army Corps of Engineers reservoirs exist along the South Dakota Missouri River mainstem: Lake Oahe (Oahe Dam), Lake Sharpe (Big Bend Dam), Lake Francis Case (Fort Randall Dam), Lewis and Clark Lake (Gavins Point Dam). Properties on or near these reservoirs have:

Rural Well and Septic

Outside Sioux Falls, Rapid City, and other municipal service areas, South Dakota uses private wells and on-site septic. Water quality testing for bacteria, nitrates, and local contaminants is required for FHA/USDA/VA loans and is good practice for all transactions.

No Transfer Tax, No Income Tax

South Dakota has no state real estate transfer tax and no state income tax — exceptional tax advantages for sellers and buyers alike.