This assessment and related data examines water resources in the South West Coast region in 2009–10 and over recent decades. Seasonal variability and trends in modelled water flows, stores and levels are considered at the regional level and also in more detail at sites for selected rivers. Information on water use is provided for selected urban centres and irrigation areas. It
begins with an overview of key data and information on water flows, stores and use in the region in recent times followed by a brief description of the region. Water quality, which is important in any water resources assessment, is not addressed. At the time of writing, suitable quality controlled and assured surface water quality data from the Australian Water Resources Information System (Bureau of Meteorology 2011a) were not available. Groundwater and water use are only partially addressed for the same reason. In future reports, these aspects will be dealt with more thoroughly as suitable data become operationally available.
Key data and information
The assessment presents the 2009–10 annual landscape water flows and the change in accessible surface water storage in the South West Coast region. The rainfall deficit that occurred evapotranspiration total is higher than rainfall) resulted in a low regional average landscape water yield1 and also contributed to further decreases in soil moisture levels. In contrast, accessible surface water storage volumes in the major reservoirs of the region increased slightly, mainly due to the fact that many of these storages are located in catchments where streamflow was at an approximately average level for the year.