Utah Code § 10-7-18

(1) All money received from the sale of property under Sections 10-7-15 through 10-7-17 shall be kept in a separate fund, and may not be expended, or mixed with other funds of the city or town, until all bonds and other indebtedness issued for the purchase or construction of the plant or works, together with accumulated interest thereon, have first been paid. (2) If the property sold brings an amount in excess of the outstanding bonds and other indebtedness issued for the purchase or construction of the property sold, the excess shall be deposited in a bank in this state under direction of the municipal legislative body, and may not thereafter be expended except for some municipal purpose by authority given by the registered voters of the city or town at a general or special election called and conducted in the manner set forth in Sections 10-7-7 and 10-7-8.