Monitoring Mallee Seeps – Project 1569C for the
South Australian Murray-Darling Basin Natural Resources Management Board
Progress Report July-Dec 2017
Chris McDonough, Insight Extension for Agriculture
At all sites there was a dramatic increase in the areas of seeps with large areas of cropped land becoming saturated and often dominated by ryegrass. While this was mainly due to the very high burden of excess water moving through the catchments as a result of the well above average 2016 rainfall, there were numerous 2017 rainfall events that were found to contribute to the perched water tables beneath.
On non-wetting sandhills with very poor water holding capacity it has been found that any rainfall event over 10 mm can quickly lead to significant rises in water table levels in the mid-slopes below. Midslope sands with slightly higher water holding capacity were found to require more significant rainfall events, closer to 20 mm, to contribute water to recharge. These are far less frequent in the Mallee.
This project is funded through the South Australian Murray-Darling Basin Natural Resources Management Board and the Australian Government’s National Landcare Program