South Africa has 4% less surface water resources than estimated in 1995, a new study published by the Water Research Commission (WRC) reveals.
The Water Resources of South Africa 2005 study, funded by WRC and carried out by a consortium of consulting engineering and scientific firms, has broken new ground by delivering an integrated assessment of surface water and underground water resources, as well as water quality country-wide.
According to Mr Wandile Nomquphu, WRC Research Manager responsible for the project, by addressing all three issues in one study, people will be reading about surface water, groundwater and water quality simultaneously.
“With each of the national water studies carried out since the 1950s, our estimate of the country’s total natural water resources has declined,” says Brian Middleton of SRK Consulting, project director of the study. “In this study, our assessment of surface water resources, for example, shows that we have 4% less than we estimated in the 1995 study. If we were allocating water according to the higher estimates made in previous studies, we would find that there is simply not the water available to meet our needs,” he says.
“As research techniques and technologies are improving all the time, the most recent findings tend to be regarded as the most accurate, regular updating of statistics relating to water is therefore vital to the country’s water security” says Middleton.
According to the WRC study, South Africa’s mean annual runoff was just over 49 000 million cubic metres of water; utilisable groundwater exploitation potential was estimated at about 10 000 million cubic metres per annum (and 25% less during drought conditions).
Middleton pointed out that groundwater is used in probably 75% of the country’s area – mainly in small towns and villages – while larger urban areas use mostly surface water.
The data in the study may affect water use strategies in a wide range of sectors, including agriculture, forestry, electricity generation, industry, groundwater developers and municipalities.
A concern raised by the study was the steady decline in the number of data collection stations for stream flow and rainfall around the country, creating gaps in geographical coverage. A task group of those agencies that help collect data has been recommended, to tackle this issue.
The data collected and stored on the WR2005 database covered South Africa, Lesotho and Swaziland, and included information on rainfall, stream flow, irrigation, groundwater, alien vegetation, afforestation, other land use, and water quality.
The study is published on a DVD, complete with databases, reports, spreadsheets and maps. There is also an Executive Summary and a Book of Maps in hard copy format.
To order a copy of Water Resources of South Africa 2005 (WR2005) (WRC Report No.: K5/1491) at the nominal fee of R120.00, contact WRC Publications: e-mail: orders [at] wrc.org.za
Source: Wandile Nomqhuphu, WRC, 23 Sep 2009
