Management on River Basin Levels

Abstract

A river basin is commonly defined as the area of land drained by a river and its tributaries. It is delimited on the surface by a boundary—not always stable and fully well defined—called a drainage divide (or watershed). A drainage basin may be intrastate, interstate, or international. In a basin, the surface streams, which naturally seek a lower level, tend to converge and unite into one main stream which discharges its flow into some larger body of water, e.g., an inland lake or the sea. Groundwater is interconnected in part or in toto with the surface system. As a resource, water may be used within the stream, diverted from the stream and then returned in part to it degraded or not, or transported elsewhere, out-basin. The interconnections within the area—between the main stream and its tributaries; the ground and the surface water; the uses and reuses of its water; the treatment of the stream and that of the effluents discharged into it at any point—give the river basin physical and functional unity. Given this unity, it seems appropriate to establish a centralized water management authority within each basin to handle the problems connected with water resource development and use in a comprehensive way. Such centralization implies the application of various instruments for the efficient use of the basin’s water bodies, for the adjustment of surface and groundwater withdrawals, for the coordination of water supply and waste disposal systems, for the management of all water-related construction and of reservoirs and dams, and for the conservation and development of the basin’s water resources overall (see Figure 10.1).