Under current state law, landowners can restrict access to rivers and streams that cross their property, unless that body of water is considered navigable (of sufficient depth for use in commerce).
That concept was tested in a recent decision from the Illinois Supreme Court involving two landowners. One landowner has two parcels along the Mazon River. One of the parcels is landlocked, so the owner would access it by paddling a kayak on the river from the other parcel. However, the owner had to traverse a part of the river that flowed through a parcel owned by a second individual. The second owner was trying to block the first owner from being able to travel that section of the river.
The Illinois Supreme Court ruled in favor of the second landowner, saying that he does have the right under state law to restrict access to the part of the river that crosses his property.
However, multiple justices on the state’s high court have urged the Illinois General Assembly to take up the matter and change state law to allow recreational use of waterways that cross private property.