Predictions of the Namoi Catchment Water Study – will they come to pass?


In 2012 the Namoi Catchment Water Study (NCWS) handed down its final report. The analysis was sobering for anyone living at Maules Creek or near the Narrabri Gas Field.

Groundwater drawdowns of “greater” than 5 m in the immediate vicinity of the projects are a huge wakeup call. Greater than 5 m could mean anything.

More worryingly for Maules Creek residents was the area of 2 – 5 metre drawdown in the area of Elfin Crossing shown by the top dark green arrow in the map below. The NCWS predicted a 2 – 5 m groundwater impact on Elfin Crossing would occur even though it is some distance from the depressurisation zone caused by the nearby Whitehaven coal mine.

The cumulative drawdown predictions shown in Scenario 1 (Scenario 1 included all extractive industry projects in the planning system at the Study’s commencement) was derived from the available data from government and company sources. By rights it would have included the Maules Creek coal mine data used in the Groundwater Impact Assessment by Australasian Groundwater and Environmental Consultants (AGE).

Despite using the same data, the NCWS predictions are at odds with the  mine consultants report which showed no decline in the Elfin Crossing area.

According to AGE, Year 21 drawdown appears to spare Elfin Crossing
AGE say that groundwater impacts do not affect Elfin Crossing in year 5


The contour maps (the full range of AGE contour maps years 1 – year 5 can be found here) conveniently show the groundwater impacts to be contained in a neat cluster around the coal mine without any impact on Elfin Crossing. The AGE modelling came out in 2011 before the NCWS Final Report release in 2012. However the NSW State approval of the mine was on the 23rd of October 2012, a couple of months after the NCWS release in July.

With the conflicting results at Maules Creek between the mine consultants and the independent NCWS, the NSW Planning Dept had plenty of time to revisit the water models. It did nothing of the sort and the Mining Minister at the time did his best to confuse, delay or nobble the NCWS. (Namoi Catchment Water Study gathering dust 23.10.2012)

The Planning Assessment Commission was clearly worried as it imposed new conditions relating to 17 additional groundwater monitoring bores and an unspecified number of core tests to better determine the hydraulic connectivity of the porous rock. i.e. coal.

It is unknown at this stage if any of this work was undertaken by the mine.

The Namoi Catchment Water Study then went into a black hole never to be seen again. The millions of dollars and countless hours of community time went with it.

Final Resting Place of the Namoi Catchment Water Study