As recently as the beginning of this century, there was little correlated development of water resources; each use was implemented separately without regard to possible conflict with other uses and sometimes to the detriment of other basin states. When technological advances increased the benefits possible from multipurpose projects and spurred planning and utilization of water resources, it became clear that optimum development required a basin-wide approach. Most basin-wide planning and execution, however, have been in national, as opposed to international, basins, such as the Tennessee (U.S.), the Damodar (India), the São Francisco (Brazil), the Cauca (Colombia), the Volta (Ghana) and the Snowy Mountains (Australia). When a river basin crosses international boundaries, unified planning and development have been more difficult to achieve. Often the approach has been piecemeal, with treaties providing for specific projects at designated sites, covering some but not all potential uses, or including only a portion of a river basin. In some instances, political difficulties have made comprehensive co-ordinated development impossible, as in the Jordan basin, or have required a physical division of the rivers, as between India and Pakistan in the Indus basin.