The prospect of saltwater invading bores has not deterred Kapiti Coast District Council from approving a river recharge project.
The council voted unanimously yesterday to lodge a resource consent application for the Waikanae River recharge scheme to boost riverflow with borewater when the river runs low.
Deputy Mayor Roger Booth said it was a significant step forward in providing a dependable, high-quality supply of treated water for Raumati, Paraparaumu and Waikanae residents.
Reports presented to councillors said there was enough water in its borefield to cover high population growth and a potential 50-year drought until 2060.
But they also indicated there was a low risk of saltwater getting into bores along the coastal fringe.
The council has not had to use its borefield for three years but previously the high mineral content of some borewater had been blamed for electrical appliances such as kettles blowing up.
Latest reports revealed underground water pockets were connected and 30 to 50 private bores in shallow aquifers and 10 to 15 deeper wells could be affected by the project in the Waikanae area.
There could be some impact, including "drawdown" in times of drought, project manager Phil Stroud said.
This meant the water level in private bores could be lowered.
The project team had been in touch with most owners of private bores in the area, Mr Stroud said.
Solutions could include injecting river water back into the borefield during winter, modifying private bores by lowering pumps, or providing an alternative water supply for the user.
The council will lodge a resource consent application with Greater Wellington regional council next month, and seek approval to take up to 30,700 cubic metres of water a day from the Waikanae River and replace it with groundwater at times of low river flows.
- The Dominion Post
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