Council welcomes water quality win at Rocky Mouth Creek
Rous County Council is celebrating better water quality through the implementation of their Active Floodgate Management Plan at Rocky Mouth Creek, near Woodburn on the Richmond River floodplain.
Monitoring as part of the Council’s recently reviewed Active Floodgate Management Plan for the waterway shows acidity levels have improved, resulting in fewer localised fish kills and a healthier aquatic environment.
Rocky Mouth Creek was first floodgated in 1965 to reduce the impact of flooding on local properties. Large drains were also constructed to reduce the time low-lying areas upstream are inundated. Together these actions created poor water quality and at times fish kills in Rocky Mouth Creek.
For the past 24 years, the floodgates have been kept open during non-flood times to allow tidal water and aquatic life to flow, known as active floodgate management.
Rous County Council’s Floodplain Engagement Officer, Chrisy Clay, said both Council and landholders at Rocky Mouth Creek support floodgate management that improves water quality leaving the Creek without impacting land upstream.
“Council and local landholders have been working together to keep this floodgate system open, outside of floods, to maintain improved water quality.
“It would simply not be possible without the participation and on-going support of the local landowners. They have been actively involved in the review and update of the Active Floodgate Management Plan for Rocky Mouth Creek and for that we are very grateful. The involvement and support of landholders is critical.
“The floodgates at Rocky Mouth Creek were some of the first in the region to be re-opened for tidal flow. The improvement that this change has made to water quality is evident and deserves celebration,” Mrs Clay said.
While tidal flow has improved acidity levels from acid sulfate soil runoff, Mrs Clay cautions that water quality is a complex issue.
“Tidal exchange has improved acidity levels in the Creek considerably, but we will still have periods of poor water quality after heavy rain or flooding, particularly from de-oxygenated water.”
The yearly average pH of Rocky Mouth Creek is now around 6. Before the floodgates were opened the system was between 3 to 4 for many months after heavy rain. This pH is comparable to vinegar and over a prolonged period will destroy downstream habitats and impact upon the health and reproduction of fish and aquatic life.
Acid sulfate soils are a naturally occurring sediment, that when drained and exposed to air, can produce acid and release metals including iron and aluminium.
Caption: The floodgates on Rocky Mouth Creek are open to allow tidal flow, which has improved water quality.
Caption: Black Swans in the Rocky Mouth Creek system. Acidity levels in Rocky Mouth Creek have improved as a result of increased tidal flow from Active Floodgate Management.