All bonds sold for any purpose contemplated by this chapter shall be sold for not less than their par value and accrued interest. The proceeds shall be deposited in the treasury of the county and placed to the credit of a special fund designated, ____ harbor fund, created by order of the commission for that purpose, and the proceeds of the sale of the bonds shall be used solely and exclusively for the purpose for which they were issued.
The commission may receive donations and place them to the credit of the fund. These shall be used only for the purpose for which they were donated. Money shall not be paid out of the fund except upon warrant of the county auditor, issued upon the written order of the commission, and duly allowed and approved by the board.