Water pipe to Renwick proposed

02:12, Mar 19 2014

Piping Blenheim's water to Renwick should be included as part of the work around improving the town's water supply, Marlborough District councillors say.

Marlborough Mayor Alistair Sowman and councillor Jamie Arbuckle teamed up yesterday to include the installation of a pump station and pipeline so that Renwick could be supplied by Blenheim's water supply.

Mr Sowman said staff should include it in their work programme. It demonstrated to people in the district that the council was looking further ahead.

Council assets and services manager Mark Wheeler said the pipeline would be the simplest way to meet national drinking water standards in Renwick.

It has been estimated pumping Blenheim's water to Renwick would cost about $600,000 less than building a water treatment plant in Renwick.

It would cost about $8.6 million to build the pipeline and pumping station, but operating costs would be significantly less than a new water treatment plant.


The town's water supply does not meet the Government's drinking water standards and it is in short supply during summer or in dry spells.

The water is corrosive and is eating at the pipes, causing leaks. Aeration treatment to reduce the corrosiveness is not working, and chlorine treatment to kill bacteria only works when the water is clear. Chlorine at levels that are safe to drink was not effective against giardia and cryptosporidium, which make people sick when they reach certain levels.

Councillors approved staff stepping up its leak detection and repair work in Renwick within existing budgets, and consultation with residents about installing water meters in the financial year 2018-2019, which would help water conservation.

They asked staff to do more work on the viability of a slow sand filtration treatment plant for Renwick, and on the option of piping water to the town.

Councillor John Leggett asked what effect supplying Renwick from Blenheim's system would have on the capacity of the Blenheim supply.

Council planning and development engineer Stuart Donaldson said there was at least a couple of decades capacity in the Blenheim supply since its upgrade, and even if growth meant higher demand, it had a "fairly extensive" ability to meet any future demand with a limited upgrade.

Supplying Renwick would take out a "chunk".

The Marlborough Express