The Wakapuaka FMU sits to the north of the Maitai FMU and flows into the sea at Delaware Bay. The main tributaries of the Wakapuaka River are the Lud and Teal Rivers, and the Swift Stream in the upper catchment. Land use in the catchment includes large areas of production forestry and native forest. Lower reaches include some pastoral activity with a large number of small lifestyle blocks, particularly in the lower Lud and Wakapuaka reaches.

There are four defined sub-catchments: Lud River; Teal River; Upper Wakapuaka (upstream of the Hira water monitoring site); and Lower Wakapuaka (downstream of the Hira water monitoring site).

Water quality is generally good with the exception of the Lud River. The main water quality contaminants are faecal, nutrients and sediment, and the impacts of pastoral use are the likely cause of this. Production forestry may also be contributing to a loss of water quality. Key values identified for the Wakapuaka include its natural form and character (in upper reaches), habitat for threatened species including inanga spawning, mahinga kai and irrigation for agriculture and horticulture production.