Wainui becoming ‘many waters’ again
- Admin
- Jun 29
- 3 min read
Driving through Wainui in recent months it would have been hard not to notice the earthworks at the Nukuhou River where it bends its way out towards Ōhiwa Harbour. In fact, a wetland is being restored where the river forms an oxbow not far from the Cheddar Valley pottery. This is the Hiwarau Wetland Restoration & Inanga Spawning Area Project, a collaborative project of the Bay of Plenty Regional Council, Hiwarau C Trustees and adjacent landowners. The Nukuhou Saltmarsh Care Group is also on board. The majority of the land where this work is undertaken is Crown reserve land; a small portion is part of the Hiwarau C block.
In this tidal area, a digger has excavated ponds at an old arm of the river and created an island. The ponds once connected provide an ideal off-channel habitat for īnanga, or whitebait, which is already understood to use the adjacent wet areas for spawning. The ponds of about 1.5 metres depth are sufficiently deep to deter aquatic weed. Closest to the main river the newly created wetland connects with existing īnanga spawning areas.
On a sunny winter’s morning in June almost 20 volunteers from the Nukuhou Saltmarsh Care Group and the Taneatua Tramping Club came together to plant the island in the centre of the newly created wetland. Following a karakia by Jo Cranswick, Fish Passage Officer at the Bay of Plenty Regional Council Toi Moana, who leads the project and a brief sharing of information, over 300 plants went into the ground, including kahikatea, harakeke (flaxes), wīwī (sea rush), karamū, mānuka, tōtara, rewarewa, carex and tī kōuka (cabbage trees).
A few of the rare maire tawake (Swamp maire) were also planted. Maire tawake are the ultimate swamp plant because of their root system that can handle being covered in water, a beautiful white flower that stands out among the others to attract insect and bird pollinators and its bright red, fleshy fruit that looks tasty to disperser birds, above all kererū. Lots of grasses were planted at the margins to provide additional spawning grounds for īnanga which in many streams in the catchment have been lost due to land use changes. At this stage a third of the island in the wetland was planted; the remaining area is planned to be planted in natives in coming years.
In the next stage of the works, possibly towards the end of 2025, the wetland will be connected with the main oxbow river channel. Waters levels will then be controlled and kept at mid-tide levels. A culvert that is currently blocked will either be maintained or replaced by a larger one to allow water flushing through the wetland.
Letting freshwater species such as īnanga flourish means important buffer zones between the land and the harbour are reinstalled. Wetlands are vital to the health of Ōhiwa Harbour as they filter runoff from pastoral land by screening sediment and nutrients. This greatly assists with the harbour’s water quality. Across the road from the oxbow this project links in well with the wetland Marli and Shane have created on their land some years ago (check out ‘From grazing paddock to wetland’ for their story). Wetland restoration projects like these allow Wainui to become true to its name again: Wainui, the place of many or great waters.
