Some Dethridge wheels are delivering nearly
25 percent more water than neighbouring meters but the extra water is not
recorded against the farmer's usage according to research results released
today by Goulburn-Murray Water (G-MW).
G-MW Managing Director David Stewart
explained that since 2007 G-MW has commissioned ‘in the field' tests of 95 Dethridge
meters as part of a program to better understand meter error and its impact on
the sharing of water resources between customers and overall system losses.
"The testing also informs our efforts
to develop a cost effective way to meet the compliance and especially the audit
requirements proposed under the National Metering standards," said Mr Stewart.
With
the third and final phase of the program now complete and to ensure the rigour
of its findings, G-MW sought a review of the statistical analysis by Monash University's Professor of Statistics
Rob Hyndman. Professor Hyndman's review confirmed an average error of
8.42% in favour of the irrigator.
"We
have previously sought independent reviews of the test methodology but not the
analysis of the results. Given the importance of this to many in the community
we felt it appropriate to seek the opinion of one of the most qualified
statistical experts and a leader in his field," said Mr Stewart.
However Mr Stewart confirmed G-MW was
more concerned with the equitable sharing between customers than the overall
average.
"If every meter over delivered by the
same amount we could simply recalibrate the meters. This research suggests that
while one farmer might get 100 ML through his wheel, his neighbour could
receive almost 125 ML each and every year. That's around $40-50,000 of
permanent entitlement and highlights the inequity that can arise from
inaccurate measurement," said Mr Stewart.
For the first time, G-MW has also
commissioned tests of 17 electronic meters.
"This is a ‘toe in the water' exercise
that will help us develop an appropriate testing regime and cost effective audit
process for these new types of meters under the National Metering Standards,"
said Mr Stewart.
Copies of the report are available from G-MW's website at www.g-mwater.com.au/metertesting.com.au
- ENDS -
Media Contact: Linda
Nieuwenhuizen
Position: Manager Stakeholder Relations
Telephone: 03 5833 5776 or 0412 183 792