Mcnett, also known as Lake Joy, is a private water resource located in Lafayette, Wisconsin. Constructed in 1971 by the USDA NRCS, this dam serves primarily for recreational purposes. With a height of 40 feet and a storage capacity of 1000 acre-feet, Mcnett spans 1100 feet in length and covers a surface area of 55 acres.

Managed by the Wisconsin Department of Natural Resources, Mcnett is regulated, permitted, inspected, and enforced to ensure safety and compliance with state standards. The dam is classified as an earth-type structure with a controlled spillway system and a low hazard potential. Despite its fair condition assessment in 2020, Mcnett poses a very high risk, with a maximum discharge capacity of 150 cubic feet per second.

The surrounding Cottage Inn Branch-Pecatonica river system benefits from Mcnett's contribution to water management and recreation. With its strategic location and well-maintained facilities, Mcnett remains a vital resource for both the local community and water enthusiasts interested in the intersection of water resources and climate management.