C1 WATER RESOURCES ASSESSMENT – Understanding resources and needs
A water resources assessment involves taking a holistic view of the water resources in a given country or region related to its use by society. The assessment looks at both the quantity and quality of surface and groundwater. It identifies the pertinent parameters of the hydrological cycle, and evaluates the water requirement of different development alternatives. The assessment pinpoints the major water resources issues and potential conflicts, their severity and social implications, as well as risks and hazards such as flood and drought. The understanding of the terrestrial and aquatic ecosystems is an essential element of resource assessment.
A good water resources assessment needs to be based on good physical and socio-economic data. Routine physical measurements at monitoring and gauging stations need to be made at appropriate times and with sufficient frequency to allow the assessment to draw valid conclusions. This in turn requires adequate financing of the monitoring system by government. Socio-economic aspects must include analysis of user behaviour, elasticity of demand, and the potential effects of demand management. Water resources assessment for IWRM sets hydrology in a wider context and considers social and economic development issues such as urban growth and changing land use patterns.
Modelling can be used to study impacts and trends resulting from various development options. However, for models to be useful in the pursuit of sustainable solutions, they must address and simulate not only economic efficiency and technical merits, but also the preferences and priorities of stakeholders. Models will only be truly useful when they are integrated into the local institutional and cultural context.