When any housing authority which is created for any city becomes authorized to transact business and exercise its powers therein, the governing body of the city shall immediately make an estimate of the amount of money necessary for the administrative expenses and overhead of such housing authority during the first year thereafter, and shall appropriate such amount to the authority out of any moneys in such city not appropriated to some other purposes. The moneys so appropriated shall be paid to the authority as a donation. Any municipality located in whole or in part within the area of operation of a housing authority shall have the power from time to time to lend or donate money to the authority or to agree to take such action. The housing authority, when it has money available therefor, shall make reimbursement for all such loans made to it.