@beth10 welcome to the forum.
You might want to check out the stunning lake maps made by @pubultrastar
bathymetric maps by @pubultrastar
My first try at a bathymetric map is in this post:
Topographic print + Bathymetric resin map
Use the search function using the term bathymetric (for water depth maps) and topographic (for land elevation maps).
We look forward to seeing what you come up with!