Where does Castlereagh River begin?
1627043#1
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.
Castlereagh River
1627043#3
Further upstream, the Castlereagh, Macquarie and Bogan rivers run ""more or less parallel as they cross the plains, where creeks and streams break away from the main rivers, making connections between the Macquarie and the Bogan, the Macquarie and the Barwon, and the Castlereagh and the Barwon. As the waterways approach the Barwon River the interconnected streams, as well as lagoons and channels, support extensive flood-dependent woodlands and grasslands"". In this extreme northern section of the catchment the floodplain between the Barwon and Castlereagh Rivers is intersected by Womat and Wanourie Creeks, which carry flows from
the Barwon to the Castlereagh River during major floods.
Castlereagh River
1627043#15
The Castlereagh sits over the Great Artesian Basin (GAB) and within a re-charge area for the waters of the GAB (where the GAB waters are replenished from above ground). Areas of re-charge are divided into zones, called ‘sources’ and the Castlereagh River is within the Southern Recharge Groundwater Source. This source, together with the Eastern Recharge Groundwater Source, is characterised by better quality groundwater than other zones.
Castlereagh River
1627043#29
In a very short period — of possibly not more than a dozen years — the Aboriginal way of life on the Castlereagh was heavily curtailed. Written evidence in 1841 from pastoralist James Walker showed this, in his response to a circular from the Commissioner of Crown Lands enquiring about pastoralists' interactions with Aborigines. Walker lived at Wallerawang, near Lithgow, but held many pastoral licences over vast stations in the Castlereagh River area from Mendooran (where 'Pampoo' was located) to Coonamble. His response included a single, but telling, comment on the effect of European occupation on Aborigines: " "... "since stock was first taken out there [i.e. to the Castlereagh] we have abridged all their natural sources of existence."
Castlereagh River
1627043#0
The Castlereagh River is located in the central–western district of New South Wales, Australia. It is part of the Macquarie-Castlereagh catchment within the Murray–Darling basin and is an unregulated river, meaning no dams or storage have been built on it to control flows. On a map of NSW, the Castlereagh has a distinctive appearance among the north-western rivers for its fish-hook-like shape: from upstream in the north at its confluence with the Macquarie River it extends southwards to a hook-shape, flattened-out at the base, which curves to the right (east and northwards) through to the tip of the hook in the Warrumbungle Mountains at the river's source.
Castlereagh River
1627043#14
The Castlereagh’s alluvial sandbeds make up what is called the "hyperheic zone". This is the region of saturated sediment below, or adjacent to, a river where surface water and groundwater are actively mixing and exchanged. The movement of the groundwater in the Castlereagh through its alluvial sands is said to be a hyporheic process. In the Castlereagh, the further transit of surface water to the aquifers of the Great Artesian Basin is then enabled through the ancient paleochannels underlying the Castlereagh, and this water movement is a large-scale hyporheic process. (Hutchinson and Webster 1998).
Castlereagh River
1627043#39
The first non-Aboriginal person to encounter the Castlereagh River was George Evans travelling in 1818 with the exploration party of Surveyor-General John Oxley. George Evans was Oxley's assistant for the tour of exploration. The group had departed from Bathurst in May 1818, sent by Governor Macquarie to explore the Macquarie River. This expedition would follow the Macquarie River to a point where it was unable to keep tracking it any further, and so would turn east away from the Macquarie, finally ending up on the coast at Port Macquarie.
Castlereagh River
1627043#5
The Castlereagh River has a highly variable flow, and often has from very low flow to no flow at all. The sandy riverbed of the Castlereagh is frequently dry in many places. John Oxley's expedition of 1818 came across the Castlereagh near Coonamble running so high and fast that it was six days until water levels dropped sufficiently to allow the expeditionary party to cross. Ten years later Charles Sturt arrived in the same general area during a ravaging drought to find the Castlereagh dry, and continuing completely dry for miles on end downstream to its junction with the Macquarie River with only occasional waterholes to be found nearby.
Castlereagh River
1627043#40
In early July, the party returned from the Macquarie Marshes to Mt Harris, 48 km (30 miles) N-NW of present-day Warren. Seemingly unable to further follow the course of the Macquarie, Oxley had to change his plans. He decided to send Evans ahead, with a small party, to scout a north-easterly route across the plains, and report back. Beginning on 8 July 1818, Evans would end up traversing a large loop, north-easterly then south-easterly, then westerly and back to his starting point. In the north-easterly direction, he first crossed the Castlereagh River around Combara, between Gulargambone and Coonamble. The party then continued on a shallower east-north-easterly direction until reaching the foothills of the Warrumbungle Mountains. From here, Evans turned south-westerly to head back to Oxley's encampment at Mt. Harris, travelling across ‘an open plain, over which was rather better travelling than we had latterly experienced’. This route brought his party back to the Castlereagh River at a point south of his first crossing, in an area between the future villages of Armatree and Curban (10 miles apart). As he approached the Castlereagh River he described the country as
‘low and wet’, with the journey being ‘dreadfully bad and marshy’. The country he was crossing over is today considered rich pasture and farming land, covering the areas known as Tonderbrine, the western side of Tooraweenah, the Yarrandale area and Hillside.
Castlereagh River
1627043#2
Downstream from Gilgandra, the Castlereagh runs through alluvial plains. These are flat landforms with alluvial soil that has been created from sediments being deposited over a long period of time by one or more rivers flowing down from highland regions. Groundwater is found in the alluvial sediments on the plains in the lower Castlereagh catchment and is generally associated with the ancient channel of the river. The Castlereagh has a very sandy bed throughout its course, with especially wide outer banks on the plains. Charles Sturt, after travelling along the Castlereagh in 1828 from Coonamble to its junction with the Macquarie, noted that there was not one pebble or stone to be picked up in its bed, which was dry for the whole length he travelled.
Castlereagh River