Sweetwater dune lakes

The Sweetwater dune lakes are a collection of complex dune lakes - Lake Ngatu, Lake Rotoroa, and Lake Heather. The largest in the chain of these, Lake Rotoroa, has high ecological values, with old kauri stumps present on the lakebed.

Dune lakes are one of nine major lake types in New Zealand. They are generally formed by the blocking of ancient stream valleys by wind-blown sand.

Dune lakes are the most common type of lake found along the west coast of the North Island.

Community conservation projects

Bushlands Trust has a number of restoration projects around lakes in the Kaitaia area including planting around Lake Ngatu and Lake Heather.

Lake Heather is included in a lake care group project aimed at protecting lakes and wetlands in the local area.

Flora and fauna

The Sweetwater dune lakes are significant homes to a number of threatened animals and plants, such as the dwarf inanga (Galaxis gracilis), the threatened New Zealand dabchick, North Island fernbird, New Zealand scaup, marsh fern (Thelypteris confluens), common bully and the freshwater crab (Halicancinus lacustris).

A native rush found at Lake Ngatu, kuta (Eleacharis sparelata) is essential to the balance of the lake offering natural filtration of pollutants. Kuta is highly regarded as a weaving material for its rich colours and its pliant and versatile properties.

Over-harvesting of kuta would cause the lake to become stagnant eventually. Weavers are able to cut and harvest the rush by permission from the local Department of Conservation, local Waimanoni Marae (Mangu Awarua Committee), and local iwi (tribe) and hapu guardians of the lake.