7-7-2274. Closing of accounts and transfer of money to other accounts. When all bonds of any series or issue, with the interest thereon, have been fully paid or called in for payment and there remains in the sinking and interest fund for such series or issue any amount not required for the payment of such bonds and interest or not used as provided in 7-7-2261, such excess amount and all amounts subsequently collected for such fund shall be transferred to the general fund of the county or to the sinking and interest fund of any other series or issue of bonds outstanding that the board of county commissioners may designate.