Water resources management in water scarce regions like the Southern Africa Development Community (SADC) is challenging with both large hydro-climatic-induced scarcity and the considerable inter-annual fluctuations at the centre of the allocation problem. Water must be allocated both in time and space using acceptable criteria and most importantly, all stakeholders must adhere to the decisions imposed by water sharing agreements. The SADC region is special in that most of its land territory (70%) falls within a designated international river basin area, creating considerable interdependences between states. For this reason, a regional framework, the SADC protocol on shared watercourses, was put in place that will guide integrated water resources development of the region. Developing water resources of the region is seen as a central element for setting the regional economy in motion. Over the past 15 years, a policy and institutional water management framework has been developed. However, materialization of the Policy and principles involved has been faced with difficulties. This research includes an analysis of water resources management in the SADC region with the view to contribute to sound transboundary water resources management which is technically accepted by all stakeholders and addresses the issues of fair and equitable water allocation. The research aimed at evaluating the role that knowledge and information has played in the progress achieved to date and to testing different methods that can assist to speed up the process. Water allocation and transparency in water resources modelling of transboundary rivers were assessed using tools that ranged from fully open sources to more complex and less transparent type of model. These models were analysed with respect to trust building for reaching water-sharing agreements. The problems related to poor integration of water quality issues in water agreement has also been investigated leading to a proposal for simple method that can enable better cooperation between riparian countries. The main conclusion of this study is that transparency, stakeholder involvement and simple methods can contribute to fast implementation of integrated water resource management in water stressed regions like SADC. In addition, Institutions should be designed to match the geographical area defined by the biophysical problem they are supposed to address