Building a Water Supply

Geotec testing being carried out for one of the potential dam sites

The 2009 Community Plan includes provision for additional water supply / storage capacity for Waikanae, Paraparaumu and Raumati, with construction commencing at Year 4 (2012/13) and completed in the following year.

Some provision for investigations is included in earlier years. The range of estimated costs for the currently known potential solutions is from $14 million to $23 million. The Council resolved to include the higher end cost at this stage until a final option has been arrived at.

The nature of the increased capacity has not yet been decided.  A review of options was tabled with Council on 17 December 2009.  There will be further extensive assessment of options undertaken, with full consideration of all environmental, social and financial issues associated with any proposed solution. An external technical advisory group (PDF, 3Mb, 162 pages) has been established to ensure a thorough assessment of options is undertaken with extensive consultation forming an integral part of the process.  This volunteer group consists of local residents, all experts in their fields.

In late 2009 and early 2010, public meetings were held to find out the community’s views on what criteria should be considered when looking at options for the water supply capacity solution.  Feedback from these meetings was reflected in an Options Selection Report and used to draw up a shortlist of possible options which was adopted unanimously be Council on 11 March 2010. The shortlist consists of six possible solutions, or combinations thereof, within the Waikanae/Paraparaumu/Raumati catchment and includes:

• Lower Maungakotukutuku Dam (PDF, 1 page, 280Kb)

• Kapakapanui Dam (PDF, 1 page, 280Kb)

• Ngatiawa Dam (PDF, 1 page, 250Kb)

• Aquifer Storage and Recovery (PDF, 1 pagfe, 265Kb)

• Extended Borefield and Storage (PDF, 1 page, 264Kb)

• Groundwater River Recharge (PDF, 1 page, 268Kb)

The six options will now be investigated further but whatever option is finally chosen will to a large degree depend on whether it could provide high quality water - the issue most important to the community. Other major considerations, based on the community’s views, are security of supply, cost of construction and operational cost.

While Council is favouring the shortlist of in-catchment solutions, Council has also decided to ask local communities and tangata whenua whether out-of-catchment solutions, such as a pipeline from the Otaki River, should also be considered. The reason for this is that, if Council wants to be successful in gaining resource consent for whatever solution is finally chosen, Council needs to be able to show that it has investigated all possible options.

Detailed conceptual designs of the six shortlisted options is now taking place and further public consultation will take place once these are completed.

For further information, please contact the Water Project Manager.