Kāwhia water

12 Janaury 2021


Kāwhia has a limited supply of water, and during normal population numbers we have surplus supply to meet the demand of the community. The water for Kāwhia comes from two springs, the North Spring and the South Spring.


Kāwhia’s population grows considerably over holiday periods. The challenge for Council is how to manage the limited resource during the influx of people, while continuing to maintain a potable compliant water supply.


Our approach this year was to put out an early water conservation message and rely on the good will of the community to take small measures to manage their water consumption. Council carried out extensive maintenance of the North Spring in November/December 2020 and standard maintenance on the South Spring. The springs were working at their optimum for the period leading up to Christmas and during the holiday period.


The demand for water in Kāwhia at the peak was double what we could supply, and if we had continued at that rate without any conservation measures we would have almost certainly run out of water. To give context, at certain times of the Christmas period, Kāwhia was consuming up to 30m3 of water an hour.  At its lowest level our reservoir reached 40% storage which is approximately 480m3 of water.


On 31 December Council issued another conservation message, asking Kāwhia residents to conserve water immediately. The extra demand was managed successfully, with Kāwhia residents still having water to meet their essential needs and enough storage maintained to meet the needs of the community, e.g. having water available for the Emergency Services.


Kāwhia has an approximate 30% level of unaccounted for water.  Unaccounted for water, sometimes referred to as water losses, or non-revenue water in Kāwhia is calculated through a minimum night flow calculation. The calculation is used as Kāwhia does not have residential water meters.

It is very difficult to ascertain whether the unaccounted for water is network related or within private property.  We have not had any network leaks reported or identified at this time, and can only assume the network is in good condition as the majority of the reticulation is sitting within sand and a leak can go unnoticed unless it comes to the surface. This makes leak detection extremely difficult for council and residents. We would like to remind residents that if they do notice anything unusual that they suspect could be a leak, to let Council know as soon as possible.


Council has a number of key projects in the waters space, some projects are already underway and some are yet to be completed. A list of these projects can be found under Appendix 1. We will also be including projects into our Long Term Plan that we consult with the community on in April 2021.




Annual Plan projects include:


  1. Replace of 1km of water main on Mountain View Road
  2. Relining of 200m of 750mm Stormwater Discharge Pipes from Flood Stations
  3. Replacement of the water clarifier in Kāwhia
  4. Replacement of the sand filter in Tihiroa Rural Water Scheme
  5. Replacement of lower section of rising water main Tihiroa Rural Water Scheme
  6. Continued automation of Ōtorohanga water treatment plant and refurbishment of sand filters 3 & 4
  7. Automation of the total phosphorus removal process at the Ōtorohanga wastewater treatment plant
  8. Improvements to the security of the water intake Ōtorohanga water treatment plant.


The government stimulus package delivery plan projects include:


Design and planning projects

  1. Pre-design and cost analysis for waste water reticulation and waste water treatment plant for Kāwhia
  2. Pre-design and cost analysis for water storage Dam on Te Raumauku Rd
  3. Investigation into alternative raw water storage and water sources for Ōtorohanga
  4. Continued design work on water treatment plants for Tihiroa and Arohena Rural Water Schemes.


Ōtorohanga Projects

  1. Continuation of water main replacement on Gradara Ave
  2. Building additional water storage reservoir on Mountain View Road.


Rural Projects

  1. Upgrade of the Kahorekau Rural Water scheme
  2. Increase storage capacity on the Tihiroa Rural Water Scheme.


We have two contingency projects which are mechanical desludging the waste water treatment oxidation ponds and further sewer main replacements in Ōtorohanga.