LAKE TŪTIRA - a clean and healthy lake
Tūtira and Waikōpiro lakes have long been popular for recreation and fishing. The lakes are central to many recreational and environmental opportunities in the area.
What do we want to fix?
The lakes have been by affected poor water quality and algal blooms for decades - the first algal bloom was recorded in 1957. This is not an overnight problem, and there’s no single cause. Rain washes soil and nutrients from fertiliser into the lake from the surrounding landscape, plus a ‘legacy load’, a build up over decades, of soil and fertiliser nutrients sits in the lake bed - both these reduce water quality and feed algal blooms.
What do we want to do?
We want to develop a comprehensive action plan to restore the lake and prevent future contamination from the wider landscape so families can once again enjoy the lake.
Over the years, there have been many actions to improve the lake such as tree planting and creating more wetland areas . HBRC bought the regional park to manage it as a soil conservation area.
HBRC has done a lot of science investigations in recent years to find out how this complex lake works and to find long term solutions.
A long term action plan - Te Waiū o Tūtira (the milk of Tutira) - sees Maungaharuru Tangitū Trust, landowners and the local community working together. The aim is to reconnect Papakiri Stream’s clean low flows (while stopping the muddy storm flows), add more lake edge and wetland planting, and consider aeration(water bubbling) technology to stop algal blooms. Careful land use planning can also assist.
Our work so far
New monitoring buoy installed - a new monitoring buoy has been installed in lake Tūtira, with the old buoy relocated into Waikōpiro.
Maungaharuru - Tangitū Trust - A partnership between HBRC and Maungaharuru-Tangitu Trust continues as we work through planning the work programme for Te Waiū o Tūtira. The Trust and hapu have been planting around the lake edges.
Air Curtain - An air curtain is being trialled in Waikōpiro Lake at Tūtira this summer (installed 21 September 2017) as work continues towards improving the water quality in the area. The trial is being undertaken as part of Te Waiū o Tūtira (the milk of Tūtira) project, which is a partnership between Maungaharuru-Tangitū Trust and Hawke’s Bay Regional Council aimed at restoring the mauri of Lakes Waikōpiro and Tūtira.
A lack of oxygen and the lake water heating up over summer has been a major factor causing algal blooms and the death of fish, which has left the lakes largely out of bounds to those who enjoy camping, swimming and boating in the area. Blooms can also turn toxic and pose risk to human and dog health.
What is it and what will it do? - Pressurised air will be pumped through a 50-metre pipe tethered close to the bottom of lake and across the deepest part, creating an air curtain. The air curtain increases oxygen levels at all depths throughout the lake by creating a circulation current, much like bubblers in a fish aquarium. The system is being piloted in the smaller Waikōpiro, and if successful a larger air curtain will be installed in Tūtira Lake.
The air curtain has been constructed on-site by HBRC’s Works Group staff, mostly out of parts found in any hardware store.
Here is a video of HBRC installing the air curtain.