Better options include taking the tree to a designated Christmas tree recycling site in your community, tossing it in the backyard to provide shelter for wintering birds, running it through a wood chipper to create your own mulch, or chopping it up for firewood.
Discarding a Christmas tree on a private pond is at the owner’s discretion, but doing so on public freshwater lakes is governed by the Lake Preservation Act (Indiana Code 14-26-2) and Indiana Administrative Code (312 IAC 11-4-7).
Those two laws require a license from the DNR to construct or place a fish attractor in a public freshwater lake. To qualify, the fish attractor must be anchored to ensure proper setting and must not be placed in a channel, a beach area, near the lake surface or in an area that would adversely affect public safety and navigation, or adversely affect the natural resources or natural scenic beauty.
Three DNR divisions – Fish & Wildlife, Law Enforcement, and Water – have a role in reviewing and approving a permit request for placement of a fish attractor. If approved, the permit carries a $100 fee and requires the permit holder to remove any portion or portions of the fish attractor that become unattached.