Institutional reform and modernisation of irrigation systems in South Africa
In the framework on Water for Growth and Development by the Department of Water Affairs, it is stated that the inefficient water use in commercial irrigation agriculture must be addressed urgently. Furthermore, reference is made to proposals that an additional 600 000 ha could be developed by water savings with improved irrigation efficiency and reduced water losses.
It is argued that these significant water savings can be achieved by continuous measuring of water application in combination with upgrading to better irrigation technology. Incentives for savings could be promoted by volumetric water user charges as a policy instrument for water demand management. Implementation of these strategies will support and accelerate ongoing trends in the application of more efficient irrigation technologies in South Africa.
Research initiated by the Water Research Commission (WRC) showed that suitable measuring devices are available which are accurate, reliable and cost-effective. ‘For this technology to be used successfully, it must be installed correctly, well maintained and meters read regularly’ says Dr Gerhard Backeberg, WRC Director for Water Utilisation in Agriculture, in a paper presented at the 5th Asian Regional Conference of ICID, held in New Delhi, India, 9-11 December 2009.
Dr Backeberg argues that guidelines have been compiled which give a detailed description of practical actions that should be taken for managed implementation of this approach. ‘With the introduction of volumetric cost recovery charges, it can be expected that more attention will be given by farmers to the efficiency levels of irrigation technologies’ he says. ‘However, reducing on-field application losses is only one consideration in the choice of irrigation technology. Micro and drip irrigation in particular requires higher capital investment and higher levels of management competence for successful operation’ he adds.
Projects completed by the Agricultural Research Council on the performance of surface and sub-surface drip irrigation found that the emission uniformity as measured in the field declined over time for all dripper types. This indicates a decline in efficiency due to clogging or lack of maintenance.
According to Mr F B Reinders, Programme Manager: Agricultural Water Resources and Conservation, Institute for Agricultural Engineering, Agricultural Research Council, correct installation and maintenance is essential and it is recommended that regular water quality analysis be carried out to identify potential clogging problems. ‘Proper maintenance schedules and their implementation are thus of utmost importance for the long-term, efficient operation of drip irrigation systems’ says Mr. Reinders. ‘The results of all these projects created useful information on costing, choice, operation and maintenance of drippers and filters. It is concluded that this knowledge must be disseminated by means of technology transfer and training sessions for designers and farmers’ he adds.
Dr Backeberg concludes: ‘The process is now under way to facilitate effective implementation and use of surface and sub-surface drip irrigation. This consists of organizing courses for designers and presenting field days for farmers and irrigation managers with practical demonstrations of the correct operation of drip irrigation systems’.
For further information contact:
Dr Gerhard Backeberg
Tel: 012 330 9043
Cell: 082 376 0845
gerhardb@wrc.org.za