SDCL § 45-9-20: Spacing units for a pool--Purposes--Establishment by board--Exception.

When necessary to prevent waste, to avoid the drilling of unnecessary wells, or to protect correlative rights, the Board of Minerals and Environment shall establish spacing units for a pool, except in those pools which, prior to July 1, 1961, have been developed to such an extent that it would be impracticable or unreasonable to establish spacing units at the existing state of development.