(1) Each county shall use an encumbrance system or other budgetary controls to ensure that no expenditure is made for any item of an appropriation unless there is a sufficient unencumbered balance in the appropriation and available funds, except in cases of fiscal emergency or natural disaster as described in Section 17-63-404.
(2) A person may not make a purchase or incur an encumbrance on behalf of a county unless that person acts in accordance with an order by, or approval of, the person duly authorized to act as purchasing agent for the county, except encumbrances or expenditures directly investigated and specifically approved by the executive or legislative body.
(3) Unless otherwise provided by the governing body, the finance officer or the finance officer's agents shall serve as a purchasing agent.