The mesotrophic Lake Rotoiti is the third-largest in the region, occupying part of the Haroharo Caldera. The lake deepens from west to east, changing from an average of 10 m deep to a maximum of 125 m. The catchment is mainly covered in indigenous vegetation and exotic forestry. There are numerous geothermal inputs to the lake, with the largest coming from the Tikitere geothermal field (source www.lawa.co.nz).
