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Integrated catchment management | LC0003 |
David Cummings, Box Hill
December, 1999 |  |
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Integrated catchment management (ICM) is a term widely used in Victoria.
But there are a number questions:
- What do we mean when we use it?
- What does it cover?
- How can it be used to improve land management activities and reduce land degradation?
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The aim of integrated catchment management is to improve land and water management.
We manage land for two basic reasons:
- to supply goods and services (eg wood, grain, milk, water, recreation, scientific study, heritage etc.); and,
- to keep the resources (soil, water, biomass and biodiversity) in good condition so that they remain healthy and productive (ie used sustainably).
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However, the extent of land degradation across Victoria is testimony to the difficulty of protecting the resources while at the same time producing the goods. This difficulty arises because of the interdependencies operating within an ecosystem.
A catchment is a convenient unit for considering these processes.
It can be used to:
- build understanding,
- provide a focus for goal setting,
- facilitate cooperation amongst the range of land managers and
- coordinate planning and implementation activities
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What is a catchment?
Geographically a catchment is that area of land which drains to a single defined point. It can be large or small and can range from the slope of a hill side (or a drained street) through to the runoff area of a major river system.
Physically a catchment is made up of of soil, water, air and vegetation. Together these components support life and make up an ecosystem in which a whole range of biophysical processes operate. Carbon based materials (the ‘energy’ materials), nutrients and water all cycle within the catchment area. Each component is linked so that changes made to one will ultimately effect one or more of the others.
Understanding the processes
It is necessary to consider land, water, environmental and social resources together when planning and implementing land management activities. A catchment conviently defines an area where where one land use activity will have effect on another. It makes it quite clear that adjoing land managers have to work together to combat soil erosion, dryland salinity, weed infestations, pest animal growth, soil acidification, or watercourse decline.
Catchment based study will give better prediction of the advantages and disadvantages of land management options. Interactions within a catchment mean that options can be analysed in terms of cause and effect. Thus the catchment provides a powerful basis for the integrated planning and management of:
- soil;
- water:
- vegetation;
- habitat; and,
- biodiversity.
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Water links
Water is essential for nearly all ecological processes. It cycles continually through all ecosystems. Not only is it essential for all biological activity, but it used over and over again as it moves through the catchment. It becomes the common bond linking parcels of land and transmitting the consequences of inappropriate management of any one of these parcels to others.
Inappropriate land management for example may:
- increase and concentrate flows of water
- reduce water delivered to downstream users
- contaminate water with sediment, nutrients, or chemicals
- adversely alter ground water levels
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Water cycle
Catchment interactions can be defined in terms of the water cycle. Water enters as rain and leaves as stream flow or as evapotranspiration. A catchment in good condition (ie not degraded) will produce stream flow which is relatively clear, clean and reasonably distributed in time.
Figure 1. A simple water balance
At the more detailed level, rain water moves in different ways once it enters the catchment and thus has a range of fates.
Figure 1. Paths of water movement in a catchment
Land management practices influence what happens to water after it is supplied as rainfall. If the practices are not sustainable this influence may lead to erosion, salinity or acidification.
In an idealized catchment, water will take a long time to move through the various parts of the water cycle.
Good soil condition is essential as the soil receives, stores and transmits the incoming rainwater. Vegetation plays two roles in maintaining soil condition by
- sheltering the soil from direct physical damage, and
- initiating biological cycling through the soil system.
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If soil is in poor condition rainfall will not easly infiltrate it; instead water builds up at the surface and runoff starts. Water will then move rapidly through the catchment leaving erosion in its wake. An additional consequence is that moisture is lost for biological uses within the catchment
People and catchments
Biophysical understanding of catchment interactions provides the base for successful ICM, but it is the social systems which will determine whether or not it occurs.
Goal setting and strategy development are therefore an important part of ICM.
Co-operation
Setting goals for the land within a catchment can only be done co-operatively. The ICM approach supports and encourages community decision making and community action. Conflicts inevitably occur but a sound ICM approach can be used to identify the base of the conflict and allow resolution through consensus.
ICM encourages the involvement of a wide range of people with differing goals, interests, skills and enthusiasms. This involvement can facilitate a successful and balanced representation of community values in catchment management.
Co-ordination
ICM acknowledges that many people need to be involved for effective land management. Primarily these will be land managers and resource managers but may need to include other interest groups to maximize community acceptance.
The interactive nature of the biophysical part of the catchment means that activities need to be scheduled appropriately. This is especially so for reclamation programs
Our catchment vision in terms of the water cycle could be written as follows:
to use all catchment waters so that:
- biological vigour is maximized
- degradation is minimized
- community benefits are maximized
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This translates to the following goals:
- Keep soil infiltration as high as possible
- Keep quantity of water flowing over soil as low as possible
- Keep plant water use as high as possible
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Soil degradation results when we fail to reach these goals.
Benefits of ICM
- More holistic appreciation of land.
- Integration of social and economic needs with natural ecosystems and the long term use of natural resources.
- Clearer identification of roles and responsibilities for implementation.
- Development of structures and mechanisms for co-ordination and cooperation.
- Development of social commitment and cohesion.
- Focus for attracting technical and financial resources allowing better utilization of local resources.
- Provides a forum for local interests and can result in early identification of potential problems.
- Provides a forum for feedback to Government.
- Healthier catchments and an improved environment.
- More robust communities
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Further reading
- Burton J.R. (1988) Catchment management in Australia. Civil Engineering Transactions pp145-152
- Christie E.K. (1993) Ecosystem changes and land degradation in McTainsh G.H. & Boughton WC (Eds) Land Degradation Processes in Australia. Longman Cheshire
- Downes R.G. (1963) The water balance and land use. National Symposium on water resources, use and management. Canberra 9-13 September. Australian Academy of Science.
- Martin P (1991) Environmental care in agricultural catchments: towards the communicative catchment. Environmental Management 15:773-783
- River Basin Management Society (1995) Catchment & Land Protection: Ideas to make it Work. River Basin Management Society.
- Soil Conservation Service(1986) Special Total Catchment Management Issue Journal of the SCS of NSW Vol.42, No.1.
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Definition
Integrated catchment management
a strategic and multi-objective approach for the improved management of our natural resources on a catchment basis. It incorporates:
- goal and priority setting for the catchment,
- assessment and monitoring of resource,
- coordination and sequencing of the management activities.
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The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.
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