Irrigators in the Central Goulburn and Loddon Valleys say they could be paying for more water than they are receiving and are claiming significant failures in Goulburn Murray Water’s metering equipment.
They say GMW’s Blade, Slip, Closed Conduit and MagFlow meters, as well as in-channel regulators were regularly malfunctioning and at times over and under reading irrigation flows.
GMW’s Central Goulburn Water Services committee chair Peter Hacon said closed conduit meters had been recording irrigation flows even when no water was passing through them.
“Any movement in the water is causing the meter to measure a flow,” Mr Hacon said.
“It could be a water flow down the channel or waves coming down on the wind. If a fish or turtle moves, it will measure it as a flow,” he said.
Mr Hacon said it had been discovered there was no connectivity between the top and the bottom of the meters.
There was no way of knowing the level of inaccuracy of the meters.
“In some channels, it fluctuates a lot, because of wind surge – it is not that they are all measuring inaccurately, it’s that they are susceptible to measuring inaccurately.”
He said he believed it was costing GMW between $1500 and $3000 to dig up each meter and attach the appropriate sensors.
The meter supplier had provided the parts but it was up to GMW to make the repairs.
“We are paying to make them fit for purpose,” Mr Hacon said.
“If there is untried technology, that’s failing or is not fit for purpose, it shouldn’t be up to GMW to bring it up to a proper standard.”
He said irrigators were also aware there were silting issues with the slip meters.
“They have a series of sensors, going up the side of the wall, and if there is silt, the sensors say there is something going through the meter,” Mr Hacon said.
“These things work fine in the laboratory, but out in the field you get all these parameters, you don’t get in the laboratory.”
Malfunctioning meters were coupled with inconsistency in irrigation flows, due to what Loddon farmers said was the failure of regulators in the the automated Total Channel Control,and Predictive Flow systems.
The regulators hold up water in channel “pools”, before it is released to individual irrigators.
Colin Fenton, who farms at Lake Meran, said there was inadequate capacity in the channels.
“We need to go back to the designers of the regulators, they must have specified a certain flow rate,” Mr Fenton said. “Where was the stuff up made and who is responsible?
He called for an independent review of how the system was working. “Any review we have had, through GMW or their consultants, has come up with a response they want,” Mr Fenton said.
Boort irrigator Lawrie Maxted said constant trouble had destroyed confidence in the system.
“I think it’s catastrophic. I know of one family who will not irrigate until they can get continuity of supply, because of the rise and fall in the channel levels,” Mr Maxted said.
GMW said 144 BladeMetres were currently being replaced under the suppliers warranty.