S.D. Codified Laws § 46A-3E-1
A water development district board of directors may levy taxes, not to exceed thirty cents per thousand dollars of taxable valuation in the district, for accomplishment of the purposes of chapters 46A-3A to 46A-3E, inclusive, and chapters 46A-1 and 46A-2. If an area is included in more than one water development district, that area's tax levy payable to each of the water development districts is determined by multiplying the greater of the overlapping water development districts' levies by each water development district's taxing fraction. Each water development district's taxing fraction is determined by dividing that water development district's proposed tax levy for the overlapped area by the sum of all water development districts' levies for the overlapped area.
SDCL 46A-3E-1