The Barossa Valley has had a groundwater monitoring network for the past 30 years. The fluctuating water and salinity levels from a complex aquifer system has been periodically recorded in over 200 individual sites. The primary purpose of the monitoring is to identify long term trends in water levels and salinity due to influences of both natural and man induced processes. The natural processes include rainfall, groundwater through-flow and seepage. Man induced changes in water levels and quality are derived from local intensive irrigation practices (enhanced discharge) and artificial recharge (recharge wells). Long term trends identified from groundwater monitoring have previously indicated that the effects due to man induced processes have generally been of detriment to the basin's water resources. However, recent changes to more effective water management practises has dramatically reduced the rate of groundwater level decline. Salinity trends are less encouraging, with strategic action required to enable a sustainable future for the area. Appropriate long term monitoring of groundwater is vital for effective management of local water resources.