(a) The governing body of a municipality, county, school district, or other local governmental unit or political subdivision, in addition to all other legal investments, may invest and reinvest money subject to its control and jurisdiction in:

(1) Obligations of the United States and of its agencies and instrumentalities;

(2) Bonds or certificates of indebtedness of this state and of its agencies and instrumentalities; and

(3) Certificates of deposit of banks which have deposits insured by the Federal Deposit Insurance Corporation; provided, however, that that portion of such certificates of deposit in excess of the amount insured by the Federal Deposit Insurance Corporation shall be secured by direct obligations of this state or the United States which are of a par value equal to that portion of such certificates of deposit which would be uninsured.

(b) This Code section shall not impair the power of a municipality, county, school district, or other local governmental unit or political subdivision to hold funds in deposit accounts with banking institutions as otherwise authorized by law.