Investigations in the Myponga Basin have shown that there is no direct evidence for groundwater depletion. Currently there are 45 irrigation wells pumping from an unconfined/confined limestone aquifer. The potentiometric surface drops 5-6 metres during November to March (irrigation season) and the aquifer appears to recover completely by October. Dominant recharge occurs along the south, east and south east margins of the main irrigation area (the Myponga plain). Discharge occurs as irrigation losses, natural runoff and sub flow loss to the various drainage channels which ultimately flow into the Myponga reservoir. An approximate water budget has shown that su^fl^w losses from the aquifer may equal 3.35 x 10 m /year. This estimate is not refined enough to be used for management of the resource, but does serve to guide future investigations. An observation well network has been established to monitor groundwater levels and salinity.