The rationale for evaluating Namibian environmental flows is essentially that of ensuring 'the maintenance of ecosystems, essential ecological processes and biological diversity' and the sustainable utilisation of natural resources as promoted in clause 95 of the Namibian Constitution. Recent policy and legislative reforms have created a unique opportunity for Namibia to incorporate environmental sensitivity clauses such as those to ensure adequate environmental flows for river systems. The Second National Development Plan and the National Water Policy White Paper form the basis for the new Water Resources Management Act, promulgated in December 2004. The National Water Policy includes a basic principle headed 'Ecosystem values and sustainability' that stresses that the management of water resources needs to harmonise human and environmental requirements, recognising the role of water in supporting the ecosystem. One of the strategies given to ensure environmental and economic sustainability reads: 'Ensure that in-stream flows are adequate both in terms of quality and quantity to sustain the ecosystem'. Although the water policy clearly states that: 'The legislation will provide for determining an environmental water reserve for freshwater sources before they can be used to supply other demands than domestic and subsistence livestock watering', there is now no direct mention of environmental flows in the new Water Act. This paper explores to what extent the need for the determination of environmental water needs has been incorporated into Namibian policies, legislation and development plans. It makes recommendations, pertinent to the Namibian situation, of what needs to be done to ensure that environmental water requirements are taken into account in future planning, operation and management of Namibia's precious water resources. Keywords: Environmental flows, In-stream flow requirements, Environmental water requirements, Environmental water reserve, Water resources management, National water policy, Ecosystem, Wetlands, Namibia.