Groundwater levels

Central Region

*The long term average (LTA) has been calculated statistically, using the long term data record for this hydrograph. The respective drought zones are used as operational triggers, and have been derived using the LTA.

Rainfall in October was significantly above average in Central region, at 234% of LTA. This reduced soil moisture deficit (SMD) and resulted in significant effective precipitation, resulting in an increase of groundwater levels, converse to the LTA trend. They are now above the LTA for the time of year. SMD remains below average for the time of year, and this will help to promote continued recharge as a result of rainfall over the winter months.

Forecasts suggest that if we receive more than 60% of LTA rainfall, groundwater levels will continue to rise through the winter, and under all rainfall scenarios, levels are likely to remain above the LTA for at least the remainder of the calendar year. The amount of rainfall and its distribution through the remainder of the winter will influence how much recharge will occur over the period, and thus the water resource position next spring.

The Chalk derived baseflow of streams across our Central region have increased due to the increase in groundwater levels, with significant runoff spikes in some also apparent.