Water management summer 2019/20
Questions and answers
Where does Kaikohe water come from?
Raw water is drawn from two sources, a groundwater supply at Monument Hill and the Wairoro Stream near the Taraire Hills water treatment plant. The Wairoro Stream is Kaikohe’s primary source of raw water, supplying about 70 percent of the town’s water. The Monument Hill water bore is the town’s secondary water source, supplying the remaining 30 percent.
Why is Kaikohe facing a water shortage?
The amount of rainfall this winter and, just as importantly, where that rain fell means the expected recharge of groundwater sources has not occurred. River and groundwater levels are currently lower than usual for this time of year. The sources for Kaikohe water are among the most vulnerable raw water sources we have, and levels have remained worryingly low after a dry winter. Both the Northland Regional Council and NIWA report that recent months have seen approximately 30 percent less rainfall than is typical. Because it takes months for the Monument Hill aquifer to recharge, current rainfall would not lift the level of that source. While some rainfall (if it falls consistently) could help our surface water supply taken from the Wairoro Stream, too much rain can dirty the stream’s water and slow down clean water production from the Taraire Hills treatment plant.
What is the Council doing to stop this happening?
The Council has been in contact with bulk water carriers and major water users in the Kaikohe area to find ways they can reduce water consumption. Measures include redirecting bulk water carriers to other supplies and prioritising leak detection work for complex and lengthy pipe networks. We hope by prioritising these users we will have the greatest impact on water waste more quickly. The Council reads the water meters of high-volume users monthly. If an unusually high amount of water is used, we immediately contact the customers and advise them. Low-volume users get readings every six months. If the Council suspect a leak, we will contact the customer.
Who are the major water users in Kaikohe, and how is the council working with them to reduce their water use?
We have met with multiple high-volume users to discuss Kaikohe’s current water challenges and how we can work together to reduce demand. High-volume users tend to be schools, laundry facilities and live-in/care facilities. Several other private and commercial users have identified leaks and, with the help of the Council, had them repaired.
Has the council done leak checks on its own infrastructure?
We completed our latest comprehensive leak detection check in mid-November 2019. Our contractor, using technology that ‘hears’ underground leaks, covered large parts of Kaikohe identifying leaks in our infrastructure for repair. Our ongoing leak detection programme covers three categories: private water users with high usage, Council-owned facilities (like pensioner housing, halls and water fountains), and our own infrastructure.
Why do households have to comply with water restrictions if they use low volumes of water?
While the Council undertakes ongoing efforts to maximise water availability and reduce waster wastage in Kaikohe, the current water resources remain fragile. Until an additional source is added to the existing supply, there will always be benefit in the community working together to reduce water consumption. Careful use of household water makes a small difference at an individual level but can make a big difference collectively. If water use was habitually reduced, Kaikohe’s sources of raw water would recharge more fully during the wetter winter months.
What is Ngawha Prison doing to manage its use of the public supply?
Prison management has committed to installing rainwater tanks next year that will be fully operational and serving the prison’s needs next summer. The new tanks are intended to store and supply enough water to cover the typical four-month dry period.
Council contractors have begun an urgent work programme intended to locate the cause of water reading discrepancies in the wider Ngawha water system, which includes the prison’s network. Prison management has said they will provide the Council with data about their water usage. Prison policy currently includes controls over usage, including limited shower times and toilet flushing.
Prison authorities have explored the possibility of restarting the non-functioning water treatment plant on its property but found that neglected equipment and poor water source quality would mean the cost would be prohibitive.
The Opononi and Omapere water supply provides water to about 900 people in the townships, including homes, businesses and schools. Water is taken from the Waiarohia Dam and the Waiotemarama Stream and treated to national drinking water standards at our Omapere treatment plant before being distributed to users through two reservoirs. In summer, a sprinkler ban (level 2 water restriction) applies.
The Far North District Council is investigating a new, secure water source to supplement the existing supply for Opononi and Omapere urban areas in dry months.
We currently take water from the Waiarohia Dam and Waiotemarama Stream, a system heavily reliant on rainfall. The lack of raw water over dry periods has been a problem for decades and water restrictions have been needed most summers since 2000. This situation will become worse in 2019 when new Northland Regional Council resource consent conditions come into force, significantly limiting the amount of water that we can take from the Waiotemarama Stream. This means use of the stream will be greatly reduced in dry weather.
We have been researching a solution for a number of years, and work closely with the Opononi-Omapere Water and Wastewater Liaison Group, which represents local residents and iwi. We considered rainwater tanks but, while these might help individual properties, they do not provide security for the whole community, especially during dry months. Taking water from the Waimamaku River was ruled out in 2007, to reflect the wishes of Waimamaku residents and iwi after a resource consent application and subsequent consultation. The best remaining option is a bore, with an expert hydrogeologist identifying a site on Smoothy Road. Preliminary testing showed there is good-quality water with an adequate flow.
We are also developing a Water Demand Management Plan to ensure the water system operates as efficiently as possible and the water is used wisely. This will be available when we commission the new water supply.