Whenever there remains in the treasury of a county an unexpended balance of a special fund and all claims against the fund have been paid, and the purpose for which it was created has been subserved fully, and there remains no further use for the balance for the purpose for which the fund was created, the board of county commissioners may transfer the balance to any other fund of the county or to the subdivision to which the balance belongs.
N.D.C.C. § 11-11-33