Data Set Name:
Short Description:
Surface Water Catchments
The catchment layer contains boundaries of watersheds where surfacewater drains to a common point
into the sea or a major waterbody. Attributes include drainage division, basin (name and number),
catchment name and drainage type. Related layers include sub-catchments, reservoir catchments and
gauging station catchments.
Update Frequency:
Irregular – As required
Last Updated:
2001
Organisation:
Department of Environment, Water & Natural Resources (DEWNR)
File Location:
http://www.waterconnect.sa.gov.au/Downloads
File Format:
ESRI Shapefile
Author:
DEWNR DEWNR.CustomerServiceCentre@sa.gov.au
Mentors:
Chris Roberts chris.roberts@sa.gov.au
Trent Daley trent.daley@sa.gov.au
Themes:
BOUNDARIES, WATER, WATER Hydrology, WATER Resources, WATER Surface
Meta Data
The boundaries were digitised on-screen (heads-up digitising) using contour and drainage layers as the reference for the
ground topography. The contour and drainage spatial layers were 1:50,000 scale TOPIS data obtained from the
Environmental and Geographic Information Division of the Department for Environment and Heritage circa 1997. Coastal
linework was also sourced from the TOPIS database.
In hilly areas with high contour detail, the catchment boundaries were digitised on-screen at scales around 1:10,000 using a
minimum vertex spacing around 25m. In other areas a smaller scale and wider vertex spacings were used to suit the lower
detail required.
In general the spatial accuracy of the catchment boundaries is similar to that of the contour data, i.e. suitable for use at
1:50,000 scale. In hilly areas with reasonably dense contour data the correct position of the catchment boundaries could,
generally, be determined with little uncertainty. In these areas, the catchment boundaries are believed to be hydrologically
correct at the scale and accuracy of the contour data.
There is uncertainty as to the correct position of the catchment boundaries in (a) flat areas with little contour detail, (b)
areas with low relief and complex contour detail (e.g. sand dunes and undulating country), and (c) urban areas where the
surface drainage is affected by stormwater infrastructure. In flat and low relief areas the boundaries are believed to show
areas that are likely to contribute to surface drainage under most conditions. However, during large flood events the flow
will cover a much larger area and may be reversed. In urban areas, stormwater infrastructure where available was used as a
guide, however, the catchment boundaries will only be approximate and must not be used at the property scale.
The nomenclature created by the AWRC was used for naming and numbering basins. The name for catchments
were taken from the major watercourse in each where such was named. The words "river" or "creek" follow each
of these names. For catchments and where the contained watercourses were not named, the name of a locality
was taken. Many coastal catchments and catchments with undefined terminal drainage were not named.
The following definitions were used to define the drainage type of catchments (stream orders were based on the
Strahler system):
 Exterior Drainage - Large catchments where the stream order is four or greater and which drain directly to
the sea or major river system (eg River Murray). Note that catchments that drain into a major river system
are strictly speaking sub-catchments of the river system catchment. However, it is convenient for resource
management purposes to consider (sub-)catchments that drain into the River Murray to be catchments
rather than sub-catchments.
 Interior Drainage - Large catchments where the stream order is four or greater and which drain to a major
internal waterbody (eg Lake Torrens). Coastal Drainage - Groupings of small catchments where the stream
order is generally three or less and which drain directly to the sea.
 Closed Drainage - Areas that are land-locked and where all drainage remains within the area and where
surface flow generally does not reach a major waterbody.
 Undefined Drainage - Areas where surface drainage generally does not reach the sea or major river system
due to flat terrain and/or losing drainage channels that peter out.
Field Definitions
CATCHMENTS – Internal catchment ID
DRAINDIV – Major drainage division
BASIN – Basin name based on the nomenclature created by the AWRC for naming basins.
BAS_NUM – Basin number based on the nomenclature created by the AWRC for numbering basins.
CATNAME - Catchment name taken from the major watercourse in area (if present) otherwise the name of a
locailty was taken.
DRN_TYPE - Drainage type (exterior, interior, coastal, closed, undefined). See above for a definition of types
For more information on Water Resources in South Australia please refer to the DEWNR WaterConnect website:
http://www.waterconnect.sa.gov.au/WaterResources