Watertable levels rising again

Thursday 14 February, 2013
The 2012 shallow watertable map, recently completed for the Goulburn Broken Catchment Management Authority (CMA), shows groundwater levels are rising.

The 2012 shallow watertable map, recently completed for the Goulburn Broken Catchment Management Authority (CMA), shows groundwater levels are rising.

For 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.

Goulburn Broken CMA's Manager for Sustainable Irrigation, Carl Walters said watertable levels less than three metres below the surface were cause for concern. Watertable levels less than two metres also pose a significant risk of salinisation, which can reduce farm productivity, damage roads and buildings, and harm environmental features.

Mr Walters said the 2012 watertable map showed the area of land where the watertable was less than three meters below the surface had increased from 9,000 ha to 182,000 ha between 2009 and 2012. "Land between Lake Cooper and Waranga Basin, south-east of Kyabram and between Echuca and Lockington had significant areas with watertable levels within two metres of the surface," he said. "The drought from late 1990s to 2009 reduced the salinity risk with watertables dropping by about three metres across the region. However with the recent return to more normal, wet weather conditions, watertable levels have risen again."

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 2012 watertable map confirms the re-emergence of the salinity threat to agriculture 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 groundwater pumping.

"The balance 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 Landcare Group or the Goulburn Broken CMA on 5820 1100 for more information.

Maps can be downloaded from: