have comparative advantage for rain-fed and irrigated agriculture but will take into account economic disparities between Member States as cited in article 5.1 of the Treaty, with a view of levelling the playing field. Water allocation and utilisation is a key consideration for food security and reduction of regional economic asymmetries, requiring that the water sector supports the SADC goal of regional food security in planning and management of water resources. Some areas of SADC are better suited for comparative and competitive cereal production, while other areas have a comparative advantage in respect of other crops and services. Member States should be encouraged requirements for national sovereignty notwithstanding - to promote areas of rain-fed agriculture and then the development of irrigation systems where these are viable for poverty reduction and job creation. Thus, instead of purely focusing on the benefits of higher productivity, that consideration is given to issues related to comparative and competitive advantage in water utilisation. 4.3.2. Policy: Water resources development for irrigation in commercial agriculture should be planned in coordination with other sectors in the interest of IWRM. Commercial irrigated agriculture is the largest single user of water in the region, presently accounting for about 70% of all water use. In the past, commercial irrigation developments were not planned in an integrated manner in collaboration with other sectors. This has led to single purpose dams and inefficient allocation of water resources. The Policy on future dam development, based on IWRM principles is elaborated in Section 8. 4.3.3. Policy: As a vehicle for promoting reliable food production and enhancing food security, sustainable irrigated agriculture and aquaculture will be promoted in all Member States with suitable water and land resources. Food production has been severely affected by droughts in various parts of the region over the last two decades. With the highly seasonal rainfall and variable flows in rivers, drought still poses a threat to food production. Reliability of available water for agriculture would promote dependable food production. Irrigated agriculture, if properly planned and well managed, would lead to more sustainable mechanisms for food production and higher productivity. Aquiculture is recognised as a vital source for healthy food production and hence, mechanisms for the promotion thereof in Member States should be developed and implemented. 4.3.4. Policy: Member States will promote improved tillage and rainwater harvesting techniques to optimise the use of water by rain-fed agriculture. The bulk of crop production throughout the SADC region is based on rain-fed agriculture. The most efficient strategy for raising production, particularly of households presently locked into subsistence farming, is to increase yields through improved tillage techniques and harvesting of “green water”. Green water refers to water in unsaturated soil responsible for the production of biomass that accounts for 60% of the world food production. This is distinctly - 26 -