Catchment Management
Author: Ernita van Wyk and Marius Claassen ~ CSIR
( Article Type: Explanation )
What is a catchment?
A catchment is defined as the area from which any rainfall will drain into a watercourse through surface flow to a common point.
Other related terms are watershed, river basin and drainage basin.
A catchment is the basic unit of the landscape that is often used to explain how the different components of the hydrological cycle interact. These components, as well as the atmospheric, marine, aquatic, terrestrial and subterranean components of the hydrological cycle, are all connected by the water itself to the broader environment. Thus a disturbance or change to the atmospheric component of the environment, whether natural or human-induced, can cause indirect impacts to the terrestrial, aquatic and marine ecosystem components of the hydrological cycle.
Integrated Catchment Management
Integrated catchment management is the management of all components of the hydrological cycle that operate within a catchment. It includes human activities that impact on and are impacted on by the different components of the hydrological cycle.
According to the National Water Act, the Department of Water and Sanitation (DWA) is not allowed in principle to undertake integrated catchment management, because that would entail management, control and regulation of activities on the land, as well as those directly affecting water.
DWA is mandated only to undertake ‘integrated water resource management on a catchment basis’, which is not as encompassing as ‘integrated catchment management’.
Integrated Water Resource Management
Integrated water resource management (IWRM) has in recent years become widely accepted as the best way to achieve sustainable water resources management as it considers all the components of the hydrological cycle and encourages public participation and transparency in decision-making.
Integrated Trans-boundary Catchment Management
This is the management of catchments across a boundary (which could be an international border; a regional, provincial or municipal boundary; sectoral boundary or a boundary between land-uses). These boundaries are generally political or administrative and rarely reflect the environment’s natural ecological boundaries, such as a catchment or river basin.
Approximately 66% of all land in South Africa lies in international river basins or catchments.
Trans-boundary catchment management is specifically relevant in South Africa, because we depend on our neighbouring countries and trans-boundary catchment areas for a significant percentage of our water supply.
The Lesotho Highlands Water Project is one such an example.
Managing catchments across political or administrative boundaries adds an extra layer of complexity to the management process since it often requires high levels of cooperation between the different political or institutional players.
Challenges to Integrated Trans-boundary Catchment Management
Some issues that influence and pose challenges to Integrated Trans-boundary Catchment Management include:
- Differing legislation and policy requirements
- Upstream–downstream variability in the water resources
- Issues of scale (geographical and institutional)
- Issues of capacity
- Legitimising data and information
- Differing socioeconomic conditions
- Differing language and communications infrastructure.
To ensure the beneficial use of these trans-boundary catchments, it is crucial that stakeholders agree on the way these shared resources should be managed in a sustainable way.
