Lake Rotorangi is the largest lake in the New Zealand region of Taranaki. The reservoir was created in 1984 by the damming of the Patea River.
Lake Rotorangi was formed in 1984 as a reservoir for generating electricity. The lake was formed by building an 80-metre high earth wall dam near the end of Ball Road in South Taranaki District. The dam created then filled the Patea River valley for a distance of about 46 kilometres to make the longest reservoir of its type in New Zealand.
The Patea Dam is owned by Trust Power and rated at 31 MW output (115 GWh per annum). Patea is operated as a peaking station. With around one week’s storage capacity, the station generates electricity over periods when electricity prices are highest. It is also a public camping ground, used in the summer time for various water sports.