Any municipal corporation subject to flood conditions, may establish in its treasury a flood control maintenance fund. Such fund may be maintained by transfer thereto of moneys derived from regular or special lawful levies for flood control purposes, moneys which may be lawfully transferred to it from any other municipal fund; and gifts and contributions received for flood control purposes. All costs and expenses for flood control maintenance purposes shall be paid out of said flood control maintenance fund, which fund shall not be used for any other purpose.