Riparian rights, bottomland ownership and underwater trespassing

As a general rule, an owner of an inland lake house in Michigan holds title to the submerged land (the bottomland) to the middle lake.¹  And while it is somewhat unusual to think of a trespass on submerged lands, Michigan courts have held that the right to use the surface water once legal access is established does not carry with it the right to anchor a float, or any other thing for that matter, in the submerged lands of another.² 

Therefore, if a backlot owner keeps a floating trampoline, for example, in the lake for the summer and the same bothers you, you might have a valid trespass claim. That would be the case only if the backlot owner is using an anchor or sandbag that is touching or affixed to your land under the surface water.

¹ See Aalsburg v Cashion, 384 Mich 236 (1970); Gregory v La Faive, 172 Mich App 354 (1988); see also Lorman v Benson, 8 Mich 18 (1860).

² E.g. Johnson v Burghorn, 212 Mich 19, 29 (1920); Hall v Wantz, 336 Mich 112, 114 (1953).