Ecosystems Need Groundwater Too! Christine Colvin Environmentek, CSIR, South Africa IAH

Groundwater discharges as…  Springs  Seeps  Baseflow to rivers and wetlands…. Stream

Groundwater also supports..  Submarine springs  Life underground  Evapotranspiration from trees

During recent years we have learnt more about negative Environmental Impacts associated with groundwater..  Pumping reduces discharge  Groundwater pathways for pollution

But less is understood about the positive Ecological Role of GW  Groundwater Dependent Ecosystems (GDEs)  Vital characteristics Quantity of water Quantity of water Quality of water Quality of water Timing of water Timing of water

Aquifers moderate water supply to the environment… Aquifers sustain GDE biodiversity, environmental services& livelihoods

In times of scarcity people and ecosytems compete for direct use of groundwater…. Who can dig deepest & fastest? We need to balance people’s needs for water and the environment.

Science can help us to understand the full picture

Scientific tools to understand vital links include…  Remote sensing  Isotopes  Nutrient and water modelling rain GW flushing

If we understand links we can predict consequences better..  Impacts of abstractions  Stakeholder trade-offs  Informed decisions

Urgent action is required to.. Recognise groundwater dependent ecosystems Recognise groundwater dependent ecosystems Start understanding links Start understanding links Monitor ecological health Monitor ecological health Seek informed decisions Seek informed decisions Allocate groundwater to the environment Allocate groundwater to the environment