Methven chosen for water meter trial


Methven has been chosen for a water meter trial that will help detect leaks in its drinking water scheme and data from the water monitoring will influence if meters will be rolled out for the whole of Mid Canterbury.

Some 918 meters will be installed in the town, which has a very high minimum night-time flow, when most people would be asleep.

The town was chosen ahead of Tinwald and Allenton, in Ashburton, and the cost of the water meters will be spread across all properties in the district on an Ashburton District Council water supply.

Council staff say the town is perfect for the trial because properties range from new subdivisions to homes more than 100 years old. Parts of the pipe network date back to 1925.

Acoustic leak detection on the Methven scheme last July found 51 leaks – 29 private and 22 public. The town is on water restrictions over summer.

Council had planned to spend $5 million over the next three years installing water meters on all ordinary connections to its community drinking water supplies. It estimates up to 50 per cent is lost through leakage and meters would help pinpoint those.

But there was big opposition when the plan went out for public consultation; people wanted evidence of the leakage and worried meters would lead to charges for excess water use.

Now council has decided to trial meters over the next year and analyse the results; staff expect monitoring to help see unusual water consumption indicating leaks that can then be repaired.

Previous leak detection work estimated Methven had a water loss of up to 65 per cent, Ashburton up to 53 per cent and Rakaia up to 36 per cent.

By comparison, Selwyn District Council reported 17.1 per cent water loss from urban public reticulation overall.

Water engineers told Ashburton councillors today water consumption in Mayfield had dropped dramatically following in the installation of water meters which identified leaks on private and public pipes, and in Mt Somers water loss had fallen from 46 per cent loss to 28 per cent loss after the installation of meters.

Smart meters, which could be screwed onto a manifold in the toby box, would normally read hourly flows but could read by the minute to pinpoint leakage.

The trial will cost around $1 million next year, the first year of council’s 10-year plan. Data analysis will happen in year 2, with rollout plans (or not) made in year 3 for the next review of the long-term plan.

Councillors voted 5-4 in favour of Methven over Allenton, with Cr Rodger Letham saying he still preferred district-wide rollout over the next three years as originally planned.

Cr Letham said meters were not an if but a when, given council’s increasing responsibility to manage and use water wisely.

Cr Angus McKay favoured Allenton. Choosing Methven would be like pouring petrol on a fire, given the number of Methven residents who were against meters, he said.

Council staff said Methven was an ideal area to trial meters because of its high leakage; there were also concerns about consent compliance as water consumption came close to annual targets.

Councillors have spent several days hearing submissions on water meters and a host of other council spending as part of its long-term plan.

After deliberations, some spending has been taken out of the budget, and more added. The end result is likely to be a small increase on the 6.28 per cent average rates increase proposed; Methven rates have been reduced from 14.8 per cent to nearer 10 per cent.

A final version of the 350-page long term plan will be presented to councillors mid-June, before adoption ahead of the new financial year in July.