How is the groundwater system performing?
Rebalancing the system means we can continue to have groundwater for communities, industry and the environment in a drying climate.
Rebalancing the groundwater system would help recover wetlands that have dried up because of declining groundwater levels, such as Loch McNess, near Yanchep.
Gnangara Mound water levels
Groundwater levels across the Gnangara Mound have generally been in decline for the last 40 years because of decreasing rainfall, continued use of groundwater for a range of important uses, and pine plantations limiting recharge. In some areas, the rate of groundwater level decline has slowed and stabilised since 2011 (see graph below). This is a positive response to the department’s actions to reduce and redistribute groundwater abstraction and reflects more consistent rainfall since the very low rainfall in the latter half of the last decade (2006 and 2010 were record dry years).
The graph below is based on monthly water level measurements at 43 monitoring bores across the Gnangara Mound. For each bore we compare these monthly measurements to the highest recorded groundwater water level. We then average the results to show relative changes in groundwater levels over time. Bores for the graph were selected from our existing monitoring network on the Gnangara Mound, with a minimum of ten years of data.