Lake Rotorua is a relatively shallow lake that was formed approximately 140 000 years ago. Hot springs provide direct geothermal inputs along the southern shore (EBOP, 2000). The Ohau channel is the only outflow from the lake, which links Lake Rotorua with Lake Rotoiti. There are nine major inflow streams and eighteen minor inflow streams.
The Lake Rotorua catchment is the most densely populated of all the Rotorua Lakes, with 8.1% of the catchment urban (EBOP, 2000).
| Water Quality | Poor but stable |
| Max Depth | 26 m |
| Catchment % pasture | 51.8% |
| Catchment % urban | 8.1% |
