Byron Shire Council is reporting a fish kill following the opening of Belongil Creek on Monday 12 October.
The creek was opened to prevent flooding after high water levels in Belongil Creek were causing inundation of stormwater culverts and drains.
The opening was in alignment with approvals from NSW Crown Lands and the Department of Primary Industries and Regional Development (DPIRD).
Belongil Creek is an ICOLL, an intermittently closed and open lake or lagoon, that is a sensitive aquatic environment susceptible to fish kills during an artificial opening of the creek.
Manually opening the creek is undertaken carefully to reduce the potential for fish kills if there is a rapid decrease in water levels in the absence of adequate rainfall," Chloe Dowsett, Coastal and Biodiversity Coordinator, said.
"Rain reduces, but does not eliminate, the chance of a fish kill and while rain was forecast by the Bureau of Meteorology on Monday, unfortunately, it did not eventuate," Ms Dowsett said.
The absence of rain and the rapid drop in water levels resulted in reduced oxygen levels in the water, causing the fish kill.
"It's not the result we had planned for; no one likes to see a fish kill and Council and government departments are investigating and reviewing the incident to inform opening protocols.
"In line with strict operational and environmental conditions that must be met, Council follows its adopted Entrance Opening Strategy and Environmental Management Plan to manually open the creek in order to balance protection of this sensitive environment with mitigation of flood risk to Byron Bay" Ms Dowsett said.
People are advised to avoid the area and not swim nearby. Dogs should be kept away, and dead fish should not be handled, eaten or used as bait.
Background to the opening
For several weeks a buildup of sand at the mouth of the creek was causing inundation in low-lying parts of Byron Bay and Belongil, with water filling stormwater culverts and drains and covering some pathways.
ICOLLs like Belongil Creek and Tallow Creek are intermittently open coastal waterways that open and close to the ocean naturally.
Council only opens these creeks if there is a significant build-up of water that poses a risk of inundation of infrastructure or property and this is always done in consultation with government departments and in line with relevant approvals.
