Except as provided in § 13-53-19, expenditures shall be made only by express authority of the Board of Regents first obtained, and no indebtedness shall ever be permitted or incurred except against funds already available for such purpose, and no expenditure from any fund shall, under any circumstances, be made except for the legal purpose for which such fund exists and for the institution to which it belongs.
SDCL 13-53-18