Fire and Emergency Southern shift manager Daniel Reilly said the Moana volunteer firefighters were called to the lake near Moana in Grey District at 3.35pm and were assisting police and St John.
Coastguard were also at the scene.
A police media spokesperson confirmed the sole occupant of the parasail was out of the lake and being assessed.A St John spokesperson said the rescue helicopter was called and assessed the person, who did not require treatment.