The Gwydir river rises on the southern part of the Northern Tablelands, near the town of Uralla, and flows about 668 km (415 mi) generally north west and then west onto the plains where it branches somewhat, eventually joining the Barwon River, mostly as its main branch the Mehi River, which branches off to the east of Moree, before passing through it.
The upper Gwydir River also passes the towns of Bundarra, Bingara, Gravesend, and Pallamallawa.
Further distributaries above Moree are the Carole which then joins with the GilGil Creek to the north that flow into the Barwon River when during times of high rainfall/runoff or water deliveries.

The Gwydir River further splits into two anabranch west of Moree - the Lower Gwydir or "Big Leather Watercourse" is the southern channel, and the "Gingham Channel" is the northern branch.
The Gingham Channel flows west and becomes undefined in wetlands and floodplains around west of Moree.
Only in larger flood events does it then join with the Ballone Creek before it flows into the Barwon River.
The Big Leather Watercourse then also loses definition in wetlands and floodplains to the west and only larger floods joins with the Barwon River to the west.
In turn, the Mehi River joins the Barwon River near the town of Collarenebri.<DECCW 2011>
Over its entire distance, the Gwydir River falls around 616 metres (2,021 ft) in elevation from its headwaters, at an elevation of 760 metres (2,490 ft) above sea level to when it joins the Barwon River at an elevation of 144 metres (472 ft) above sea level.
The Gwydir River's total length is 488 kilometres (303 mi), in which space and thirty-four tributaries feed into it over its entire length; including the Horton River, Warialda Creek, Laura Creek and Moredun Creek.
The Gwydir river rises on the southern part of the Northern Tablelands, near the town of Uralla, and flows about 668 km (415 mi) generally north west and then west onto the plains where it branches somewhat, eventually joining the Barwon River, mostly as its main branch the Mehi River, which branches off to the east of Moree, before passing through it. The upper Gwydir River also passes the towns of Bundarra, Bingara, Gravesend, and Pallamallawa. Further distributaries above Moree are the Carole which then joins with the GilGil Creek to the north that flow into the Barwon River when during times of high rainfall/runoff or water deliveries.
The Gwydir River further splits into two anabranch west of Moree - the Lower Gwydir or "Big Leather Watercourse" is the southern channel, and the "Gingham Channel" is the northern branch. The Gingham Channel flows west and becomes undefined in wetlands and floodplains around west of Moree. Only in larger flood events does it then join with the Ballone Creek before it flows into the Barwon River. The Big Leather Watercourse then also loses definition in wetlands and floodplains to the west and only larger floods joins with the Barwon River to the west. In turn, the Mehi River joins the Barwon River near the town of Collarenebri.<DECCW 2011>
Over its entire distance, the Gwydir River falls around 616 metres (2,021 ft) in elevation from its headwaters, at an elevation of 760 metres (2,490 ft) above sea level to when it joins the Barwon River at an elevation of 144 metres (472 ft) above sea level. The Gwydir River's total length is 488 kilometres (303 mi), in which space and thirty-four tributaries feed into it over its entire length; including the Horton River, Warialda Creek, Laura Creek and Moredun Creek.
Gwydir River