Sustainability
of Groundwater Resources and its Indicators (Proceedings of symposium S3 held during the
Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS
Publ. 302, 2006, 10-20.
Using sustainability indicators as a basis for classifying
groundwater in South Africa
ROGER PARSONS1 &
JOHAN WENTZEL2
1 Parsons & Associates Specialist
Groundwater Consultants, PO Box 2606, Somerset West 7129, South Africa
2 Department of Water Affairs and Forestry,
Private Bag X313, Pretoria 0001, South Africa
Abstract Under the South African
Constitution, everybody has a right to an environment not harmful to their
health and wellbeing; to have an environment protected for the benefit of present
and future generations; and to have access to sufficient food and water. The
main responsibility of the Department of Water Affairs and Forestry (DWAF) is to
ensure sufficient water of an acceptable quality is available to meet basic
human needs, and to support economic and social development. South Africa is
not a water-rich country and, as a result, water has to be managed and used
wisely. Under new legislation, water management in South Africa is now based on
three key principles, namely sustainability, equity and efficiency. The
National Water Act (Act 36 of 1998) (NWA) requires water to be set aside for
environmental and basic human needs before allocation for other uses. A key
mechanism to achieve this is classification of water resources. A classification
system for groundwater resources is currently being developed. While trying to
integrate the groundwater classification system with those of other components
of the hydrological system (rivers, wetlands and estuaries), indicators are
being used to identify the point at which groundwater use is no longer
sustainable. Potential indicators being considered include sinkhole formation,
saline intrusion, decrease in river and spring flow, and vegetation die-off.
Observation of any of these conditions requires the resource be classified as a
D category or worse, thereby requiring management intervention to modify use to
within sustainable limits.
Key
words classification; groundwater; indicators;
sustainability