Journal of Pollution Effects & Control
Open Access
ISSN: 2375-4397
+44 1223 790975
ISSN: 2375-4397
+44 1223 790975
Mahasa P S, Palamuleni L G and Ruhiiga T M
University of the Free State, South Africa
North West University, South Africa
Posters & Accepted Abstracts: Pollut Eff Cont
The study addresses uncertainties that emanate as a result of methods used to determine irrigation areas in the upper Orange River catchment area. The largest water user is the irrigation sector. What is not known for all schemes are the return flows but an average estimation of 13% is done for the main irrigation areas? Though several previous studies have addressed water conservation and demand management in the Orange-Senqu River catchment area; some pitfalls/caveats remain identified by these studies pertaining to the practical implementation of results. It was necessary to look into several methods used since the results produced, in some instances differed so much. The major problem in the study area is the unlawful water abstractions for irrigation use. In South Africa, indications show that about 240 million m3 per annum of illegal water use is due to unauthorised withdrawals or violations of water use licenses. The status of water use for irrigation in the upper Orange-Senqu Basin also shows that insufficient information exists such that work needs to be done to understand the potential for increased efficiency of water use, taking into account issues pertaining to crop type, soil type and technological options. Studies like this one could also shed light on the potential impact of climate change on water use in the basin as this area may well experience significant impacts from rising temperatures and changing rainfall patterns. The processes of validation and verification will determine the extent of existing lawful water use. The use of remote sensing techniques (satellite, aerial photographs, etc.) could be employed to determine if the volume of water use registered by irrigators is accurate, i.e. valid and that the volume of water use registered is lawful (verification). Currently, ecological requirements for the river mouth are met through releases from Vanderkloof Dam and amount to just 290 million m3 per annum. However several recent studies including the Gesellschaft f�¼r International Zusammenarbeit - Integrated Water Resources Management (GIZ â�� IWRM) study highlight that this is based on a fairly outdated methodology. The more recent Lower Orange Management study found a high level estimate of ecological requirements to be in order of 1,062 million m3 per annum.
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