Along the west coast of South Africa, where precipitation rates are often less than 400 mm/year and rivers are mostly ephemeral, access to water is a critical limitation on development. However, west coast groundwater is variably saline in areas, can damage sensitive ecological systems, and is often not suitable for domestic or agricultural use. SASSCAL has installed weather and groundwater monitoring instruments along the west coast, with a focus on the RAMSAR-listed Verlorenvlei estuarine lake, to understand the interdependence of domestic, agricultural, and ecological water requirements. Groundwater modelling in the upper parts of the Verlorenvlei catchment intends to show that baseflow from the Krom Antonies tributary is a critical source of low-saline water that also supports economically important agricultural activities. Early results of the Krom
Antonies groundwater model suggest that pumping regimes in the Verlorenvlei catchment are at or near maximum capacity. This would suggest that future changes in pumping regimes, through, for example, changes in land use patterns or precipitation patterns would need to be carefully managed to maintain sufficient baseflow supply to the tributaries feeding into the Verlorenvlei  estuarine system. Lessons learned in this catchment will be applied to the data-poor Buffels River catchment further north to improve our understanding of west coast hydrology and how it will be affected by future climate change.