The authority of the county engineer shall be limited to the requisition for the expenditure of funds for the purpose of construction, maintenance, or repairs of public roads, bridges, ferries, or any other duties for Macon County as may be set aside and appropriated by the commission as hereinafter provided. It shall be the duty of the commission at some meeting in September of each calendar year, or not later than the first meeting in October following, by order or resolution spread upon the minutes, to fix and determine the amount of funds which shall be available for the purpose of building, maintaining, and constructing public roads, bridges, and ferries of Macon County for the current fiscal year, beginning on October 1, which amount, other than the salary of the county engineer, shall not be exceeded in the performance of duties required of the county engineer for that period. The commission is authorized from time to time within any period, to increase the amount so allowed to be expended by the county engineer during the period, when the authorization will not conflict with general law under the Budget Act, Section 11–8–3. Immediately upon August 1, 1997, if funds are presently available and have not been set aside by the present county commission for the current fiscal year, it shall be the duty of the commission to set aside a sufficient portion of the balance of the funds for the maintenance of the roads, bridges, and ferries until the next meeting in September or October as provided by this article.