Mich. Comp. Laws § 560.141: Improvements.

Sec. 141.

When the plat includes or abuts certain improvements other than streets, alleys, roads or highways, such as county drains, lagoons, slips, waterways, lakes, bays or canals, which connect with or are proposed to connect with or enlarge public waters, the included or abutting portions of such proposed improvement shall be shown on the plat.