I owned a 5 foot wide parcel once and got an Education from the School of Hard Knocks. In Minnesota, every person who owns lakeshore whether an inch or a mile has water rights including the right to wharf and place structures on the submerged land underneath the water, and others. The rights are timeless and can be exercised at any time. A person can buy or sell these water rights with or without land, easement, etc. Property lines do not extend into the water generally, rather the whole lake bed is a separate lot owned by the State in trust for the public. The DNR administers the zoning and regulations on the submerged land below the Ordinary High Water Level. Municipalities zone the land above the OHWL–but cannot prohibit the construction of dock (even though they occasionally try). The surface of the water can be zoned / regulated as well (Lake Minnetonka Conservation District as an example). If the body of water is or was at any time connected in a navigable way to the Mississippi or other large commercial river Federal law protects your right to build aids to navigation. Adjacent property owners must make a reasonable adjustment for your reasonable placement of structures–you couldn’t operate a marina with 100 boats on the 15 feet–you might not be able to have more than one dock and lift depending on what is perceived to be reasonable–it can’t interfere with other peoples use of the water. That is true for you and for your neighbors under a principle we call “The Reasonable Use Doctrine”–similar to the Golden Rule. See specific citations to Statutes and Case Law by visiting this link: MN Riparian Rights, or message me with specific questions.