Conserving precious water
This week water supply restrictions are being lifted across the district, in response to consistent rainfall improving both river flows and soil moisture levels.
Thankfully we did not experience a fullblown drought this summer, but conditions have been dry across much of the Far North. As early as October river and soil moisture levels were in decline. According to Niwa, even now soil moisture in the very Far North remains lower than normal, particularly on Aupo¯uri Peninsula. This has prompted the organisation to name the peninsular a soil moisture ‘hot spot’ for May 2019.
This weather put our streams, rivers and ground water sources under pressure, forcing the council to introduce Level 3 restrictions on four of our water supplies. RaweneOmanaia, Opononi-O¯ma¯pere, KaikoheNgawha and Kawakawa-Moerewa all faced bans on sprinklers and hoses. Level 2 sprinkler bans were also applied to the Kaitaia, and KerikeriWaipapa supplies.
It was unusual for Kaikohe to face Level 3 restrictions. Its water supply is normally very resilient. However, forestry work in the area had significantly increased sediment levels in the Wairoro Stream catchment, the town’s primary water source, meaning volumes that could be filtered at the Taraire Hills water treatment plant were significantly reduced. To compensate we took more raw water from our bore at Monument Hill. Unfortunately, this increased reliance on our secondary supply meant underground aquifer levels became depleted. As a result, both Kotahitanga Marae and Kaikohe’s historic Aperahama Church, which rely on the same aquifer, faced the prospect of their spring running dry.
The people of Kaikohe rallied following calls from the council and Waikotihe Trust, the kaitiaki of the spring, to cut water consumption. Because of this community effort the spring continued to flow over summer, and the aquifer is now showing signs of recovering.
Across the district the council is working hard to improve the resilience of its water supplies. In Kaikohe we aim to increase capacity at the Taraire Hills plant and so reduce reliance on the aquifer, and in the Hokianga our most sensitive supplies are also being improved. We are due to complete a new $2.8 million water treatment plant for Omanaia and Rawene in August, while we hope a new bore at Smoothy Rd will increase raw water supplies for Opononi and O¯ ma¯ pere residents.
In Kaitaia we are investigating new extraction options from the Aupo¯uri aquifer, and stepping up a programme to identify and repair leaks in the town’s reticulation system. Similar leak identification programmes will be undertaken at our other water supply schemes.
It is crucial that we improve the resilience of our water supplies. Just as important is for all of us to reduce consumption. Kaikohe residents have demonstrated just how effective reducing demand can be, and I want to acknowledge and thank them for their efforts throughout the summer.
"Kaikohe residents have demonstrated just how effective reducing demand can be, and I want to acknowledge and thank them for their efforts throughout the summer."