SDCL § 45-9-21: Spacing units for a pool--Size and shape, establishment by board, modifications and exceptions.

Except where circumstances reasonably require, spacing units shall be of approximately uniform size and shape for the entire pool. The Board of Minerals and Environment may establish spacing units of different sizes or shapes for different parts of a pool or may grant exceptions to the size or shape of any spacing unit or units or may change the size or shape of one or more existing spacing units.