Trees

Watertable levels rising again

Friday 18 April, 2014
The 2013 shallow watertable map, recently completed for the Goulburn Broken Catchment Management Authority (CMA) by Goulburn-Murray Water, shows that despite a below average rainfall year the groundwater levels have remained relatively constant.

The 2013 shallow watertable map, recently completed for the Goulburn Broken Catchment Management Authority (CMA) by Goulburn-Murray Water, shows that despite a below average rainfall year the groundwater levels have remained relatively constant.

For over 30 years watertable levels across the Shepparton Irrigation Region (SIR) have been mapped to understand trends and to communicate the salinity risks to the region.  The most recent map is featured in today’s Country News on page 9.  Copies can also be downloaded from the Goulburn Broken CMA’s website: www.gbcma.vic.gov.au

Goulburn Broken CMA Manager Sustainable Irrigation Carl Walters said watertable levels within two metres of the surface were cause for concern. 

“At that level they pose a significant risk of salinisation, which will reduce farm productivity, damage roads and buildings, and harm environmental features,” Mr Walters said.

The 2013 Watertable Map shows the area of land where the watertable was within three meters of the surface had increased from 9,000 ha to 151,000 ha between 2009 and 2013

Mr Walters said rising watertable levels were causing concern by the 1970s and by the mid-1990s almost 50 per cent of the region had water within two metres of the surface.

In response, a Land and Water Management Plan for the region was developed in partnership with the community, state government and regional agencies to combat the effects of the high watertables with works such as improved drainage, groundwater pumping, Whole Farm Planning and strategic revegetation.

“The works that were completed in many areas over the last 20 years have demonstrated the ability to protect our irrigation region from rising watertables,” Mr Walters said.  “The 2013 watertable map confirms the continued threat  of the salinity to agricultural production and the environment and highlights the need to ensure salinity management is adaptive enough to respond to variable climatic conditions and the changing irrigation footprint. 

“This watertable mapping project is a great example of sharing information with the community and increasing awareness about the need to take action to protect the productivity of the region and our environment.”

Mr Walters said approaches to tackling the problem included efficient irrigation, surface drainage and appropriate sub-surface drainage or shallow groundwater pumping. 

“The balance and connection between all of these actions in the right places at the right time has been critical so far in our region and the community-driven planning for response has proven to be the key,” he said

Landholders are encouraged to contact their local Landcare group or the Goulburn Broken CMA on 5820 1100 for more information.