Ecological Use of Groundwater

Christine ColvinEnvironmentek, CSIR, South Africa

IAH

Springs

Seeps

Baseflow to rivers and wetlands

Stream

Groundwater also supports..

Submarine springs

Life underground

Evapotranspiration from trees

Environmental Impacts

Pumping reduces discharge

Groundwater pathways for pollution

Understanding Dependency

Groundwater Dependent Ecosystems

Vital characteristicsQuantity of water

Quality of water

Timing of water

Aquifers moderate water supply to the environment…

Aquifer Storage

Biogeochemical processes

Aquifers sustain environmental services

& livelihoods

Competition with people….

Who can dig

deepest & fastest?

Balance people’s

needs for water

and the

environment.

Science to understand the full picture

Understand vital links…

Remote sensing

Isotopes

Nutrient and water modellingrain

GWflushing

Understand consequences of actions..

Optimal beneficial use

Impacts of abstractions

Stakeholder trade-offs

Informed decisions

Urgent action required to..

Recognise groundwater dependent ecosystems Start understanding links Monitor ecological health Seek informed decisions Allocate groundwater to the environment