8.3.2. Policy: Water-demand Management (WDM) will be pursued by Member States as a fundamental requirement for integrated planning and management of water resources, particularly in shared watercourses. Water-demand Management is the use of price, quantitative restrictions and other devices (e.g., leakage detection and control in water supply systems) to control the demand for water. The potential benefits of WDM are significant, both from a national viewpoint and in terms of creating an appropriate framework for regional co-operation between shared watercourse States. WDM needs to be vigorously pursued by Member States in all river basins. In a regional setting, one of the fundamental aspects is that upstream countries should be making the best use of the water being extracted from shared watercourses. Before negotiating for higher levels of extraction, a full programme of WDM (involving appropriate levels of both technical and allocative efficiency) should be evaluated and implemented. The level and intensity of WDM effort that is appropriate and economically efficient will change over time. When demands on shared water are modest, it would be unreasonable to require extreme WDM measures to be applied by upstream users. Most WDM measures involve costs, for example the capital investment associated with moving to a more sophisticated water efficient irrigation technology. There is a trade-off to be made between the investment costs incurred upstream and the value of the water made available downstream. As pressure on the shared resource grows, a higher level of efficiency of use, and thus higher WDM effort, will become justified in the upstream country. 8.4 Alternative Sources of Water 8.4.1. Policy: Member States will promote alternative sources of water such as rainwater harvesting, desalination, reuse of water, recycling and reclamation. Relevant research should be promoted as and where appropriate. The importance of increasing agricultural yields through improved tillage and rainwater harvesting has already been discussed in Section 4.3.1. Rainwater harvesting also has potential to enhance availability and security of water supplies in urban areas. This is particularly useful in those areas not connected or far away from centralised municipal water supply systems, such as in periurban areas. As the technology improves and costs diminish, use of solar energy to desalinate seawater could provide an important source of water for certain locations in SADC at a future stage. Member States should cooperate in research initiatives to assess the potential for, and the best practical mechanisms for implementation of alternative water sources such as rainwater harvesting, recycling and reuse. In view of the constrained resources within SADC to support extensive research initiatives of this nature, significant benefit may be derived from an investigation of the existing body of research findings from appropriate international studies on alternative sources of water. - 40 -