Council’s water strategy focuses on achieving additional water supply and reducing average water use through improved conservation.
The challenge for additional water supply is substantial, with many environmental, social, cultural and financial factors. Extensive consultation took place with the community in 2010 on what was important regarding water supply. These factors were taken into account in the assessment of a wide range of water supply options.
After an exhaustive process, in August 2010 Council selected River Recharge with Groundwater as its preferred option. It has also bought land for a dam behind Nikau Valley as part of a longer term solution.
Resource consent was applied for in November 2012, and a 35 year consent was granted in September 2013. The scheme is expected to be in operation in 2015.
The second goal is the reduction of water use to a peak target of 400 litres per person per day. The ‘litres per person per day’ measure is an average for all users, including businesses, industry, schools, councils and individuals at home. It also allows for some water that is unaccounted for – water lost in large reticulation systems.
While this amount is generous by New Zealand standards, the challenge is considerable as current peak consumption in Kāpiti ranges between 540 and 560 litres per person per day – and in some areas it can be as high as 760.
A Water Conservation Plan has been developed to help achieve the target of 400 litres per person per day.
The Council has worked in partnership with tāngata whenua on the water supply issue.
Council and Iwi signed a Memorandum of Understanding with Te Ati Awa relating to water that formed the basis for Iwi consultation on the water supply project.
Tāngata whenua, through Council partnership committee Te Whakaminenga o Kāpiti, said: “Water is a valuable and important natural resource [that is] fundamental to future development management on the Kāpiti Coast.”
Council met regularly with a wide range of stakeholder groups during the selection of its preferred option. The wider community commented on suggested initiatives as part of the Annual Plan and Community Plan process.
1. River Recharge with Groundwater
This option gained resource consent approval in September 2013.
When the river level is very low, it allows Council to take more water from Waikanae River by recharging it with groundwater from the Waikanae borefield. Groundwater extracted from wells will ‘replace’ the river water used for supply, downstream of the Water Treatment Plant. Every extra litre extracted from the river will be offset by a litre of groundwater discharged downstream to maintain river’s natural flow.
Once fully operational it means during very dry periods there will be no need to mix our drinking water with groundwater – ensuring a consistent quality of supply.
2. Maungakotukutuku Dam
Land was purchased in 2012 for a dam on the Maungakotukutuku Stream behind the hills of Nikau Valley.
The dam is Council’s second ranked water supply option. However, with the River Recharge scheme and anticipated reduction in water use, a dam may not be needed for 50 years.
This option involves creating a 28 hectare lake behind a 31.5 metre concrete dam. Stored water from the dam will be released into the Waikanae River to supplement the river's natural flow as required. Geotechnical drilling in the area has confirmed no active faults or significant concerns with foundations. Some covenant protected land that will be affected has been offset by creating additional 95ha of new covenanted land. Ongoing pest management is required for the covenanted areas to increase its biodiversity values over the next 50 years.
The 'river recharge with groundwater' scheme and future dam are expected to provide a secure source of good quality water for the next 100 years.
Council consulted with local communities and tāngata whenua in early 2010 about what was important to them about additional water supply for Raumati/Paraparaumu/Waikanae. The Ōtaki Community Board advised Council that out-of-catchment solutions, such as the Ōtaki River, would not be supported by the Ōtaki community.
Council had also earlier indicated that it prefers in-catchment water supply solutions for the district. This is documented in the 2003 document Water Matters which outlines the district’s 50-year water management strategy and was reaffirmed during the Water Project consultation in 2010.
Further, in 2001 Greater Wellington Regional Council declined consent for an Ōtaki River pipeline. Revisiting the Ōtaki pipeline proposal is likely to cause a protracted and costly consent process.
Consultants developed designs and costings for a number of ‘in-catchment’ options as well as two Ōtaki options to ensure a complete picture was provided.
Their assessment went to Council on 19 August 2010.
One Ōtaki option involved drilling shallow bores at the river’s edge and piping water 16.5 kilometres to the existing water treatment plant at Waikanae. It had a $37.8 million price tag.
The second option involved drilling shallow wells near the Ōtaki Gorge and a pipeline to transfer water to the top of the Waikanae River catchment. It had a $32.8 million price tag. In addition, pumping and piping costs would be significant.
The Ōtaki options were costed on a like-for-like basis and were clearly outside the $23 million budget set by Council in the 2009 LTCCP.
In January 2003, Kāpiti Coast District Council adopted a Sustainable Water Use Strategy. The strategy has a 50 year focus and is concerned with reducing demand for water, while investing in new infrastructure for the supply of water to the community.
The goals in the Sustainable Water Use Strategy were further refined in the Kāpiti Coast District Council 2009 Long Term Community Plan and 2012 Long Term Plan. Large sections of the community contributed to the development of this plan, reflecting the importance residents attach to this issue.
The district-wide installation of water meters is expected to reduce water demand by 20 percent.
In addition, Council offers a range of practical initiatives on water such as:
For more information, contact the Council’s Water Use Advisor.
New regulations also help to conserve water. Since 2011 new dwellings must have a 10,000 litre rain water tank or a 4,000 litre rain water tank, and a grey water diversion system. This is a groundbreaking regulation in New Zealand and underlines Council’s commitment to sustainability.
The Council has an active leak detection programme and any leaks can be reported 24/7 on 0800 486 486.
There are many ways to conserve water, from grey water plumbing systems to planting the right plants for local conditions. You can contact the Council’s Water Use Advisor for more information.
Most of the water used in the district is taken from the Waikanae River, and treated at the Waikanae Water Treatment Plant before being piped to residents and businesses in Waikanae, Paraparaumu and Raumati. Smaller facilities service the Ōtaki, Hautere and Paekakariki water supplies.
The Council works hard to identify leaks, but some water loss is inevitable in a large reticulation system.
It costs money to capture, treat and pipe water to end users, and the infrastructure required to do this must be able to cope with ‘peak’ demand. This is the highest amount of water used on any single day – and usually occurs in summer when river levels are low.
Kāpiti has a high ‘litres per person per day’ water use, so reducing water consumption is an important part of the district’s water strategy. It is now also a requirement under the River Recharge consent.
The River Recharge Scheme and reduced consumption brought about largely by water meters will together provide a 50 year solution to the district’s water supply.
The River Recharge scheme will increase capacity and ensure a consistent quality of water even in times of low river flow. Reduced consumption through water meters and other conservation moves will enable capital investment to be staged over a longer period.
At present peak consumption ranges between 540 and 560 litres per person per day, with some areas as high as 760.
Our capital investment in water infrastructure is based on getting peak consumption down to 400 litres per person per day. Water meters will be critical to achieving this.