The board of directors, with the approval of the city or county governing body, may build, lease, lease-purchase, or purchase an appropriate building for a library and purchase a site therefor. Such lease, purchase, or contract shall not be valid without the approval of the governing body of the city or county. Prior to any actions on such proposals, the governing body shall hold a public hearing on the proposals. Notice of the hearing shall be published at least once, not less than six days prior to the hearing, in a newspaper of general circulation within the city or county. The governing body shall seek the advice and comment of the state library and the general public at the hearing. After such hearing, the governing body of a city or county may establish by resolution a library building fund for the purpose of construction, enlargement, or alteration of a building or for the purchase of an existing building to be used as a public library. The city auditor or county treasurer shall place in the library building fund all moneys for such purposes as may be appropriated by the governing body or received for such purposes from federal, state, county, city, or private sources. The library building fund shall not revert to the library general fund or the general fund of the city or county without authorization by formal resolution from both the library’s board of directors and the governing body of the city or county.