Indicator protocols: baseflow salinity

Product Information

Stream salinity is a useful indicator of catchment salinity. It may be comprised of baseflow (groundwater) and surface water components. Baseflow salinity is important because it indicates the relative contribution of groundwater salinity to total stream salinity.

In more rapidly-responding local groundwater flow systems, rising baseflow salinities over time generally indicate an increasing groundwater contribution to the stream flow and, therefore rising watertables. It is also an indicator that can be readily measured by community based initiatives such as Waterwatch or Saltwatch, and its value is often an educational and community involvement tool, as much as a salinity indicator.

Baseflow salinity can be a useful means for identifying sub-catchments where further salinity investigations may be warranted, it can be a difficult indicator to interpret correctly. Baseflow salinity levels can vary quite erratically, and to use baseflow salinity as an indicator for the potential development of salinity problems it needs to be interpreted in conjunction with other contributing factors such as climate and land-use. The indicator may be of limited use in catchments with ephemeral stream flow.