Long Term Averages plotted on the graphs are calculated from the period of record January September 1923 to October 2019.Please note: At Whitedale, we have measured groundwater data at two different locations. The minimum level displayed on the graph uses data from our original borehole. Our new borehole should measure 10m lower than the original site (down to 22.20 mAOD). This means that when levels are very low, the observed data will fall below the existing minimum threshold line. Once this occurs, then we will update our minimum statistical values held for the site.