Water Management

There is an increasing focus on the sustainable management of water resources, including improving natural waterways and stormwater discharges to lowland streams, providing good quality drinking water, and safeguarding sustainable sewage and stormwater disposal systems

What We Do

The Council looks after the district’s water supply, wastewater (sewage) and stormwater, including urban drainage, rural drainage and stockwater. We build and maintain infrastructure such as pipes, to

  • ensure residents have a constant supply of clean drinking water
  • treat and remove wastewater 
  • protect groundwater quality, and
  • clear stormwater through the drainage system

We’re also working in partnership with community members and Environment Canterbury, through the Waimakariri Water Zone Committee, to develop sustainable plans for the district’s rivers, streams and ground water resources.

About 10,800 residents source their water from privately owned bores, and a similar number have individual on-site septic tanks. The Council does not actively manage these private systems or their water quality.

What We’re Doing

Water Supply

Over the last 10 years the Council has carried out upgrades to ensure drinking water supplies meet current Drinking Water Standards for New Zealand. The approach has been, where possible, to seek ‘secure’ deep groundwater that does not need treatment. By July 2018 all of the Council’s 16 drinking water supplies will be upgraded, except for the Garrymere and Poyntzs Road schemes which will be completed in 2019.

The recent Report of the Havelock North Drinking Water Inquiry:  Stage 2 is recommending that Drinking Water Standards be changed. If the recommendations are carried out, for our District it will mean that all ‘secure’ deep groundwater will need to have ultra-violet treatment and all on-demand supplies in our urban communities will need to be chlorinated. Restricted supplies, mainly in our rural communities, are already chlorinated. Chlorination equipment is in place for all our supplies. However, only the Mandeville/Fernside and Waikuku Beach supplies have ultraviolet (UV) treatment installed.

Over the first 4 years of this LTP, the Council has included approximately $3 million for the installation of ultra-violet treatment systems to meet future (higher) standards. For large urban communities the cost is expected
to be less than $30 per property per year, whereas it may cost up to $200 per property per year for small rural schemes. The rate will vary depending on the number of ratepayers on each scheme.

While it is likely chlorination of all schemes will be required and budget provisions have been made for this, the Council has decided it will not start chlorinating schemes in advance of any revised Drinking Water Standards. Results of recent community consultation have been strongly in favour of having unchlorinated water, even though the community were made aware of the risks. At the moment there is still some uncertainty over the likely requirements and timing of any changes to the Drinking Water Standards. The rate for water scheme chlorination, which includes operational costs is estimated to be $9 per property per year.

Wastewater

The 7 treatment plants operated by the Council have resource consents from Environment Canterbury. These allow discharge of wastewater to either the land or ocean. Testing for suspended solids, biochemical oxygen demand, nitrogen, phosphorus, faecal coliform, and enterococci is undertaken as required by the resource consents. The Council also regularly tests water quality on the beach between The Pines Beach/Kairaki and Woodend ear the ocean discharge.

A 10-year infrastructure improvement programme aims to reduce the number of wastewater overflows resulting from rainfall. Improvements to the Rangiora system have been underway for 2 years and a similar improvement programme will begin in Kaiapoi in 2018.

Stormwater

The Council is developing Stormwater Management Plans (SMPs) to improve the quality of stormwater discharges from urban areas into our streams and rivers. An additional budget of $100,000 each year of the LTP has been
allocated to ensure we meet the requirements of the Land and Water Regional Plan by 2025.

The SMPs will identify methods to reduce quantities of dissolved metals such as zinc and copper running off hard surfaces (such as roofs and building exteriors, or from vehicles and roads) during rainfall events and flowing into
our drains and streams.

Each major town in the District requires a stormwater discharge consent. Staff are currently preparing comprehensive applications which require attention to manage the quantity and quality of water that flows into our drains and streams.

The priority for each consent is to outline the network capacity upgrades required by 2025 to help reduce flooding in each town and to improve water quality by 2040. Preliminary estimates suggest it may cost up to $100 million over the next 30 years to meet the standards required under the discharge consents. The likely impact on rates would approximately be $200 to $250 per property per year.

Flooding

Following the June 2014 floods in the district, the Council approved capital works projects to improve the capacity of the drainage networks in rural areas of the district, particularly around Mandeville. Budget was also approved for the Rangiora Urban and Kaiapoi Urban drainage schemes. 

The total amount budgeted for repairs and drainage upgrades was approximately $21 million, of which $7 million of work has been completed. 

We have included a new operating allowance of $150,000 per year to the flood response budget. This rate would be charged to all the district’s properties, averaging $6 per property per year and will be used to deal with areas that are not currently in a drainage rated area that contribute to downstream issues in a flood event.

Glyphosate Testing

The Council has a resource consent from Environment Canterbury to spray watercress, monkey musk and veronica with the herbicide glyphosate in our waterways. Approximately 8 to 10% of spring-fed drains are sprayed every year at a cost of about $15,000. 

Community concerns have been brought to the Council’s attention regarding the use of glyphosate, especially over water. The Kaiapoi Community Board has recommended the Council approves the use of mechanical means rather than spraying to control weeds. This could potentially cost an additional $80,000 to $100,000 per year or $4 per property per year, to manage spring-fed waterways across the district. It would cost approximately $525,000 to
$945,000 per year, or $20 to $40 per property per year, if all drains and waterways were cleaned this way. We’re proposing to retain our current approach to the maintenance of  waterways and drains.

Waimakariri Land and Water Solutions Programme

Waimakariri District Council works with Environment Canterbury (who have the overall responsibility for water management in Canterbury) via the Waimakariri Water Zone Committee.


The Land and Water Solutions Programme is a collaborative project led by the Waimakariri Zone Committee to encourage community contributions on how to achieve better water quality. 

The Zone Implementation Programme, is a package of recommendations prepared by the Waimakariri Zone Committee and is expected to be completed in September 2018. This will provide proposals on how best to deal with the freshwater and ecological issues facing the Zone, including river flows, surface water quality as well as groundwater recharge and movement. The Council contributes $35,000 a year supporting the Committee’s activities. As the programme of work has yet to be defined it will be considered in a subsequent Long Term Plan or Annual Plan.

OTHER PROJECTS

The 2 projects that our Council lead on are as follows.

KAIAPOI RIVER REHABILITATION

A joint working group has been setup to improve the Kaiapoi River. This includes investigations on water quality, navigability, flood hazard management, recreation, and formation of wetlands.

CAM RIVER FUND WORK

As an outcome of the mediation agreement around the historic discharge from the Rangiora Sewage Treatment Plant, $250,000 is being spent on the creation of sediment traps, drainage wetlands, bank reshaping and fine sediment removal in the Cam River catchment to restore habitats within the waterways.