The Michigan Court of Appeals recently said no. In Wenners v Chisholm, the plaintiffs owned property on Portage Lake in Washtenaw County. The defendant owned a back lot, but she and the previous owners of her property had accessed the lake using a strip of land located between the plaintiffs' properties for more than 30 years.

The trial court found that the defendant had established a prescriptive easement for ingress and egress to the lake. However, the easement did not include riparian rights, and the defendant was barred from installing a dock or mooring any watercraft in the lake.  

The defendant argued that the trial court could not grant her a prescriptive easement for lake access without also giving her riparian rights. The Court of Appeals rejected her arguments. It concluded that since the defendant could not show that she and the previous owners of her property had exercised riparian rights for a 15-year period, the prescriptive easement did not include riparian rights.

Had the defendant presented evidence showing that she and the previous owners of her property had installed a dock and moored a boat in the lake for at least 15 years, perhaps the outcome might have been different. But without that, the defendant's easement to access the lake did not include riparian rights.