(a) The county board may levy a tax on the taxable property within the county to acquire, better, and construct county library buildings and branches and to pay principal and interest on bonds issued for that purpose.

(b) The county board may by resolution adopted by a five-sevenths vote issue and sell general obligation bonds of the county in the manner provided in sections 475.60 to 475.73. The bonds shall not be subject to the limitations of sections 475.51 to 475.59, but the maturity years and amounts and interest rates of each series of bonds shall be fixed so that the maximum amount of principal and interest to become due in any year, on the bonds of that series and of all outstanding series issued by or for the purposes of libraries, shall not exceed an amount equal to 0.01612 percent of estimated market value of all taxable property in the county as last finally equalized before the issuance of the new series. When the tax levy authorized in this section is collected it shall be appropriated and credited to a debt service fund for the bonds in amounts required each year in lieu of a countywide tax levy for the debt service fund under section 475.61.