This article is a concept. Please contribute research and information toward the development of this concept.
The concept revolves around the question: Is it possible to live on the Grand River in a Houseboat or Floating House?
Is it legal?
It appears that rights to moor probably need to be given by the Raparian owner of the riverside land. One alternative would be to own river-side land.
Michigan State Law
What is a Raparian?
"For purpose of clarification, a riparian owner is simply one who owns land or property abutting water. Actually, a riparian is one who owns land contiguous to a river or stream, and one who owns lands contiguous to a lake is properly called a littoral owner. But in common practice, both are referred to as riparians." 
Access to Public Waters
"2. The Mooring of Houseboats on the Inland Waters From time-to-time the mooring of houseboats on inland waters becomes a controversial problem. The Legislature, through enactment of MCL 123.591; MSA 5.2965(1), authorized County Boards of Commissioners, outside the corporate limits of cities and villages, to regulate, by ordinance, the location of houseboats on those portions of lakes, rivers, canals and waterways of the county under their jurisdiction. Unquestionably, the county has the authority to prohibit, by ordinance, the mooring of a houseboat on an inland lake. The owner of the bottom lands on which the houseboat is moored also has a cause of action for trespass. However, although it is a technical trespass it is strictly a civil matter. The riparian owner should consult the county for possible action by that entity or seek the counsel of an attorney." 
Other Controls over Rivers
"In administration of the laws enacted by Congress for the protection and preservation of the navigable waters of the United States, the Army Corps of Engineers exercises jurisdiction over the waterways listed below, from their mouths to the heads of navigation as follows:
NAME OF WATERWAY … HEAD OF NAVIGATION
Grand River … Fulton Street bridge at Grand Rapids, 40 miles above mouth." 
The history of houseboats on the Grand River in the past is unknown.