Mich. Comp. Laws § 280.471
The drainage board may contract with the federal government, which term as used in this section shall include any agency thereof, whereby the federal government will pay the whole or any part of the cost of the project or will perform the whole or any part of the work connected therewith, which contract may include any specific terms required by act of congress or federal regulation as a condition for such participation on the part of the federal government. The drainage board may also contract with any private corporation or with any public corporation, which term as used in this section shall include any agency thereof, in respect to any matter connected with the construction, operation, maintenance, use or services of any drain. Such a contract may provide for service or transportation charges and that any payments made or work done by such corporation shall relieve it in whole or in part from assessment for the cost of the drain or of its maintenance and operation. No construction work shall be undertaken until the drainage board has advertised for and received bids for the performance of such work, except for construction work to be performed by the federal government or a public corporation.
MCL 280.471