The Gwydir valley extends from the Northern Tablelands to the Northern Plains, where it joins the Barwon River, covering an area of 26,596 square kilometres. The Gwydir River system and its wetlands are located on a semi-arid floodplain, in a relatively low rainfall zone.
Inflows to the system in the 2020–21 water year provided ideal nesting conditions for waterbirds by supporting native vegetation growth and driving an abundance of food in the form of booming native fish, frog and insect populations.
Breeding was detected in 18 waterbird species, which included a small colony of great egrets, cormorants and magpie geese on the Gingham watercourse. Cormorants and darters were also detected nesting along the Lower Gwydir River during surveys in February 2021.
Survey teams detected 9 frog species in spring and summer. This included all 6 frog species known to breed in response to wetlands flows.
Releases of water for the environment were also made into the Mehi River and Carole Creek and provided an important contribution to flows further downstream in the Barwon River system.