Lake Ngatu is 55.8 hectares in size with a maximum depth of 6.3 m. The lake is surrounded by native scrub, with some fenced pasture and housing on the northern edge of the lake. It is a popular recreational lake with easy access which makes this lake vulnerable to the spread of pest plants. Lagarosiphon major was first recorded in Lake Ngatu in 1988. Its spread in the lake has been limited due to the particular water chemistry found in the lake. However the nutrient status of Lake Ngatu is showing evidence of change and may lead to rapid weed growth impacting on its currently high ecological status. In response the Department of Conservation in collaboration with Ngai Takoto Iwi and the local community are in the process of establishing a management plan for the restoration of Lake Ngatu (source www.lawa.co.nz).