The role of the River Basin in IWRM?
Drainage basins, also called catchments or watersheds, include all the land that drains into a river, from its source to its mouth (Dunne and Leopold 1978). The Global Water Partnership and International Network of Basin Organisations (INBO) publication A Handbook for Integrated Water Resources Management in Basins (2009), recognises the river basin as the practical hydrological unit of choice for water resources management. There are a number of interchangeable terms for river basins, including catchment and watershed, but internationally, the term basin is widely used and recognised.
Why is it Important?
The River Basin Approach is important as it is becoming an internationally accepted approach for Water Resources Management. Furthermore, as it is based The role of the River Basin in IWRM The role of the River Basin in IWRM The role of the River Basin in IWRM on the River Basin as a unit of management and many basins are transboundary, it is equally important to integrated water resources management (IWRM).
The Limpopo River basin is shared by four countries - Botswana, Mozambique, South Africa and Zimbabwe. While each of these countries may have different requirements and agendas with respect to the river, they must all cooperate to meet their objectives.
The Limpopo River Basin, a transboundary river basin.
( click to enlarge )
Geographical Challenges Presented by IWRM
IWRM is a challenging undertaking, even more so when dealing with a transboundary setting. However, there are many challenges specific to the River Basin Approach, two of which are data and groundwater resources.
Data
In a transboundary setting, most data are collected at a national level and, with the exception of a few rare cases, have been gathered for different periods of time, using different methods and stored using different approaches and technologies.
The River Basin Approach requires basin-wide data to be collected in the same formats and to the same standards and collated either uniformly or for an additional basin-wide programme to be put in place, which can be an expensive under-taking.
Groundwater
As the River Basin Approach uses a surface water unit as the basis for planning and management, it does not always encapsulate all of the groundwater resources, as groundwater aquifers do not necessarily conform to the same boundaries as surface water resources. While some transboundary (across national borders) aquifers may exist within the basin, some may transcend the surface water basin boundary. Therefore, considerations must be made for inter-river basin groundwater flow, particularly with respect to development of water balance budgets.
