Lake Katherine, a 20-acre man-made lake, was designed to be the focal point of the reclaimed spoil site that was developed into Lake Katherine Nature Center and Botanic Gardens. An adjacent waterfall cascades down the eastern edge of the lake.

Lake Katherine supports a healthy population of fish. The lake is home to muskie, largemouth bass, bluegill, hybrid sunfish, channel catfish and black crappie. The lake is also home to muskrats and beavers, whose lodges and burrows are built into the shoreline. A wide variety of amphibians and reptiles inhabit the lake, including turtles, frogs and snakes. A number of water birds and shore birds can be found here as well.