The largest collection of water quality data (groundwater and surface water) for the Richmond river basin is maintained by the New South Wales Government. These data include continuously collected water quality parameters and targeted sampling campaigns. Continuously collected surface water quality data are not widely available for gauging locations in the Richmond river basin and most of the measurements that are available only commenced in 2013. Continuous surface water quality measurements include salinity (represented by electrical conductivity) and water temperature and are collected in the tidal reaches of the system. Changes in continuously measured electrical conductivity is linked to flow conditions in the river basin.
Targeted surface water sampling campaigns have been carried out in the past with databases held by both the NSW Department of Environment and Heritage (), and the New South Wales Office of Water (). A large number of surface water quality parameters have been monitored through the Richmond river basin but the most commonly reported are electrical conductivity, pH and turbidity. Using the Australian and New Zealand Guidelines for Freshwater and Marine Water Quality , most water quality parameters were found to fall within acceptable levels, however, there were times where limits were exceeded for the most commonly reported parameters.
Groundwater quality data are available from the New South Wales Office of Water for more than 500 bores within the Richmond river basin. Parameters that are most commonly measured are salinity (represented by electrical conductivity) and pH, collected over a time span from 1971 to 2007. The freshest groundwater within the Richmond river basin is contained within the Lamington Volcanics. Groundwater salinity within the alluvial aquifers is more variable, ranging from very fresh to saline, depending on the location within the river basin. Only limited water quality measurements exist for the deeper bedrock aquifers within the Richmond river basin; to provide a baseline understanding of groundwater quality within the major aquifers, observations from other areas within the Clarence-Moreton bioregion are also reported in this report.