That whenever it shall be ascertained and determined that any natural watercourse in one drainage district is accustomed by its overflow to injure lands situated in any other drainage district organized under this act, or lands situated within the territorial limits of any similar corporation organized under the laws of any other state, the board of directors of such first drainage district shall have power to enter into contracts with such other drainage district or corporation, or with any owners of land subject to overflow situated outside such first drainage district or state, to co-operate in the construction of levees or other works to prevent such overflow, and shall also have power to receive donations or aid in constructing levees or other works from persons or corporations who own property outside of the limits of the district that will be benefited thereby; and whenever two or more drainage districts organized under this act or any drainage district and any similar corporation organized under the laws of any other state determine that by cooperation they can more advantageously carry on the work of constructing a continuous levee or other work that will afford common protection and benefit to the property owners and people of such districts or territories, then such districts may contract with each other or with such foreign corporation, and unite in causing any improvement to be made, the proportion of the cost to be contributed by each to be first fixed by agreement between them, and each drainage district organized under this act may issue bonds or levy special assessments to pay its proportion of the cost of such joint undertaking. Any districts or any district and foreign corporation so cooperating may jointly advertise for, accept bids and make joint contracts for the construction of any such levee or other works, but no district shall be bound by any contract to pay more than its share of the cost of such work, so to be determined and apportioned before the contract is made.