Richmond River Water Quality Report 2023
A joint project between Rous County Council, Dept of Planning and Environment & Southern Cross University saw the installation of water quality monitors along the mid to lower Richmond River.
A report analysing the results has just been released, reviewing 1.5 million measurements taken from March 2021 to January 2023 (see below).
Some key points from the report are:
- Blackwater (low oxygen) events can occur after rain events of any magnitude
- Chronic acidic discharge occurs after rain events of any magnitude
- On average, water discharging from the RR floodplain is very acidic andat 50% oxygen saturation
- The Blackwater event following 2022 flood occurred along ~55km of the River resulting in mass fish kills
- Broadscale land use change, and different land & water management, is required to reduce blackwater events and acidic discharge into the River
Interesting points:
- 87 fish kills have been recorded in the Richmond River since 1970
- DO and pH levels are lower than ANZECC guidelines 100% of the time in some locations
- The mid to lower River appears to experience general routine hypoxia (low to zero oxygen)
Table 1: Percentage of samples that did not meet ANZECC guidelines for dissolved oxygen, pH and turbidity at each site (the ANZECC guideline range for Estuaries is shown in italics for each parameter).
