Lakes and ponds produced by impounding the Mad River behind dams offer deeper, cooler, larger habitat areas in which fish of numerous species are able to thrive.

Scovill Reservoir, which occupies roughly 120 acres (0.49 km2) along the river in central Wolcott, is known to support trout, largemouth bass, sunfish, yellow perch, chain pickerel and black crappie.

[3] Prior to settlement by the Connecticut Colony, the broad region encompassing the Mad River was a hunting ground frequented by native Algonquian people of the Mattabesec and Tunxis tribes.

One observer of the Mad River in 1887 noted that water downstream of Scovill Manufacturing Company, one of the foremost brass producers in Waterbury, "showed extreme contamination; it was of a dark turbid color, with a strong odor and was covered with iridescent films of oily and greasy matters".

Finally, significant industrial pressure on the Mad River ceased by the 1980s when the brass and copper companies in Waterbury, which had been in decline since World War II, shuttered the last of their major factories.