This report is a progress report to supplement a previous report - "The Northern Adelaide Plains Groundwater Study to May 1968". As a result of the investigations since that time more detail is available on the Quaternary aquifers, recharge to the aquifer systems, and withdrawal. Since completion of the 1968 report groundwater investigation in the Northern Adelaide Plains has been concerned mainly with the Quaternary aquifers but there have also been additional investigations into the Tertiary aquifers. As part of the investigation since 1968 a total of 63 bores were drilled into Quaternary aquifers and 4 bores in Tertiary aquifers for a total depth of 3 250 metres. In this report the various comments of the hydrologic equation are first considered in some detail, leading on to a discussion of management problems in the basin. As regards withdrawal, which is one aspect of the hydrologic equation, this is now known with greater accuracy as all irrigation bores have been fitted with meters since November, 1970.