[1][2] It is five kilometres in length and covers 12.3 km2, however it is only 2.6 metres deep (and as low as 1.5 m during summer).

The Utakura River (south-western margin) is the main outflow which goes to the Hokianga Harbour.

The lake catchment is predominantly pasture, with a few areas of native scrub and mature bush.

[3] Lake Ōmāpere is of great cultural and environmental value to Māori tangata whenua.

[8] The lake is monitored by Northland Regional Council, and the environmental information can be viewed on the LAWA website.