1. Ecological and environmental impacts of large-scale groundwater development in the Table Mountain Group (TMG) aquifer system

2. Research context WRC and DWAF research programme: “The hydrogeology of the TMG aquifers” 1) Understanding occurrence, attributes and dynamics of the TMG aquifer systems 2) Understanding environmental impacts of exploitation from TMG aquifer systems 3) Integration of groundwater in broader water management framework

3. Objectives for eco-impacts project Develop predictive tools, innovative techniques and indicators to assess impact of groundwater abstraction on the environment Improve understanding of GDEs in TMG & sensitivity to groundwater fluctuations Improve understanding of impact of changing low flows on freshwater ecosystems

4. Approach Phase 1: Scoping – inception study, data collation and field study planning (started June 2002) Phase 2: Field data collection (one year) Phase 3: Analysis of results and assessment of dependencies of ecosystems on groundwater Phase 4: Recommendations for the application of current knowledge and critical future research

5. Determining the study area Considerations: Practical/logistical aspects Existing data and infrastructure Range of GDEs represented City of Cape Town project target areas  catchments of the Berg, Breede and Riviersonderend, focusing on the CCT area (Kogelberg to Witzenberg)

6. Purpose of scoping workshop Scope the full range and types of potential ecological impacts of large scale groundwater abstraction from the TMG aquifer Identify geographical areas and ecosystems considered likely to be dependent on groundwater Prioritise areas for future monitoring and research

7. Team and potential themes Southern Waters Umvoto CSIR Ninham Shand UCT UWC US GEOSS WCNCB DWAF Groundwater flow in TMG system Determining groundwater contribution to baseflow Groundwater use by terrestrial ecosystems Ecological role of hydro- geochemistry Dependency of wetlands on groundwater Knowledge management and spatial databases

8. Links to CCT pilot study on feasibility for extracting groundwater from the TMG for municipal supplies WRC project  wet (July-Aug 2003) and dry (March-April 2004) season baseline monitoring, including control sites WRC project  limited monitoring areas WRC project  establish monitoring protocol that can be continued by CCT project