Groundwater resources are vulnerable to the impacts from unconventional gas development. In South Africa there are interests in exploiting shale gas resources in the South Western Karoo region. South Africa offers a unique opportunity to implement a statistically sound groundwater monitoring network in an undeveloped shale gas system. This study presents a design for a groundwater monitoring network using a novel hybrid hydrogeological-geostatistical approach. A multi-criteria decision analysis (MDA) techniques was applied to develop a groundwater vulnerability map, combined with a kriging model to optimize the positioning of monitoring points. Using this approach the existing network was increased from 34 points to 95 monitoring points. The newly designed network shows improvements in the collection of baseline data, specifically in vulnerable zones.