In 1933 further investigations and exploration were carried out at the isthmus. This demonstrated that there were two aquifers; an upper unconfined one of fresh water and a lower confined one of brackish water. Development of the upper aquifer was then carried out. The water from the wells is conveyed to a tank at Hesses Pumping Station from where it is pumped up to the Waterworks to be blended with desalinated water. The water derived from these wells is high in chloride content and has a high degree of hardness.