Lake Opuha is a short side trip to the northeast of Fairlie, of State Highway 79 on the way to Tekapo. But it feels like the middle of nowhere when you visit, even though it is surrounded by farms. Take Mt Michael Rd from SH79 about 10 kms or so before Fairlie.
The lake was created by a dam for use as a reservoir. But there is a walking track around the south side from the dam and a boat ramp, and it is used for recreational purposes. It was very calm when we took the photos, resulting in some excellent reflections of the surrounding hills, mountains and sky.