As Planners, the term "catchment" has many meanings and is used in relation to many planning issues. There are catchments for shopping centres, recreation facilities, traffic management and water catchments, to name a few.
Water catchments and the need to focus our planning on this vital component of our ecosystem is one of the key issues facing Rural Planners today. It is an issue that affects Planners in Local, State and Federal Government as well as Consultant Planners. It is also an issue that crosses into other professions - Environmental Sciences, and Engineering being the main ones. Catchment Planning is also of interest and concern in the community. The rise in prominence and interest in the Landcare movement is an example of this.
First of all it is necessary to define the term "catchment". Basically, a catchment is an area of land that can be defined as a natural drainage area. Catchments have varying and different landforms which form the boundaries - hills, ridges and mountains, sloping and flat land - and catch the water runoff which flows to a low point. This can be either a river, lake or the sea. Catchments are of varying sizes. They can be large and encompass an entire river system like the Hawkesbury Nepean (which covers most of the Sydney region) or the Murray Darling (15% of the Australian Continent), or they can cover a small creek and have an area of several hundred hectares.
One thing to remember is that all land is in a catchment and all uses of the land will have an impact on the catchment. It is also important to recognise that a catchment is made up of many smaller catchments or sub-catchments. A catchment is also a physical system with its own ecosystem which provides habitat for plants and animals. To retain the biodiversity of the catchments it is important to recognise het corridor value of catchments and the links between catchments that are provided so that the gene pool is maintained.
Land uses in a catchment are both varied and disparate. They can range from natural bushland to disturbed or modified landforms such as grazing to industrial to urban residential and rural residential. Each one of these has its own impacts on the health and sustainability of the surrounding land - the catchment.
A catchment also has common and individual constraints and opportunities which must be addressed in any attempt to manage the use of the land which comprises the catchment or sub-catchment. Planners manage the environment and provide policy advice on the best management practices to ensure the health and sustainability of the sub-catchments and wider catchments. The issues relating to catchment management can range from land degradation to flora and fauna protection to varying development proposals.
It is for this reason that our planning focus should be on the relevant catchment or sub-catchment which is a physical system and not on arbitrary lines on the map which delineate property boundaries or Government administrative boundaries. It is important that we see the big picture of a development proposal and assess fully the impacts of any proposed development on the catchment or sub-catchment. This applies just as much to the assessment of a development application as it does to a major rezoning proposal.
There is a need to think about the wider picture when we are considering preparing a draft LEP for example so that all of the impacts of a proposal are considered and addressed in the relevant Local Environmental Studies. If you think about the wider catchment first you can then narrow the study area down into smaller sub-catchments. This cannot be done once the study area has been defined and the study commenced without considerable expense and perhaps duplication of work already carried out.
|| Rural Planning Wheel ||
launched March, 1999