Castlereagh River
The Castlereagh rises 20 km west of Coonabarabran in the heart of the Warrumbungle mountains at an elevation of about 850 metres. From its commencement upstream in the mountains the river initially flows east through the town of Coonabarabran. It then arcs round south and southwesterly to the village of Ulamambri, then south to Binnaway, and SSW to the small town of Mendooran which lies at the eastern side of the river's hook-shape. From here the Castlereagh flows in a westerly direction at the flattened bottom of the hook and then turns north-westerly towards the town of Gilgandra. From Gilgandra it continues to run northwesterly across the plains through Gulargambone and Coonamble, then continuing across expansive plains, with no urban centres, where elevations are less than 200m, until it joins the Macquarie River at its uppermost reaches beyond the Macquarie Marshes. Its confluence with the Macquarie is about 65 km SW of Walgett. Not far from the Castlereagh/Macquarie confluence the Macquarie itself joins the Barwon River at a place about halfway between Walgett and Brewarrina.
Ulster Canal
The Ulster Canal is a disused canal running through part of County Armagh, County Tyrone and County Fermanagh in Northern Ireland and County Monaghan in the Republic of Ireland. In the early 19th century the idea of linking the lowlands around Lough Neagh with the Erne Basin and the River Shannon system became popular with the more progressive landowners and merchants of Armagh, Monaghan and Fermanagh. The Ulster Canal was built between 1825 and 1842 and was 74 km (46 mi) long with 26 locks. It ran from Charlemont on the River Blackwater to Wattle Bridge on the River Finn, south-east of Upper Lough Erne. It was an ill-considered venture, with the locks built narrower than the other Irish waterways, preventing through trade, and an inadequate water supply. It was an abject failure commercially, and contributed to the collapse of the Lagan Navigation Company, who took it over from the government but were then refused permission to abandon it when they could not afford the maintenance costs. It finally closed in 1931. Waterways Ireland started work on rebuilding the canal at its southern end in 2015.