Situated 4 kms west of Tumbarumba, Mannus Lake is a popular location for recreational fishing, boating, walking and bird watching and brings tourism and economic benefits to the local area. The capacity of the dam is 2350 ML.
Snowy Valleys Council is actively monitoring Mannus Lake for blue-green algae. Alert levels are published in consultation with WaterNSW.
Council has engaged the University of Technology Sydney (UTS), to undertake a research study of the algae bloom in Mannus Lake.