Hawkesbury River is in New South Wales, Australia. Its headstream, the Wollondilly, rises near Goulburn. But the river is officially known as the Hawkesbury from the junction of the Grose and Nepean rivers to its mouth at Broken Bay, north of Sydney. 
The area around the Hawkesbury was the main source of grain for early European settlers in New South Wales. Ships carried goods from Sydney to Broken Bay and then sailed up the Hawkesbury. In 1789, New South Wales Governor Arthur Phillip named the river after the British statesman Baron Hawkesbury. In 1794, Lieutenant Governor Francis Grose sent settlers to the area. In 1810, Governor Lachlan Macquarie visited the Hawkesbury settlements and named the five towns now known as the Macquarie Towns. They are Windsor, Richmond, Castlereagh, Pitt Town, and Wilberforce.
Farmers in the area had been accustomed to living in bark shacks. But Macquarie insisted that houses built in his towns be made of brick or weatherboard (a kind of board used for exterior siding), and have brick chimneys and shingled roofs. Macquarie encouraged the settlers to seek sanctuary from the frequent flooding of the Hawkesbury by offering them allotments for houses in his new towns. The settlers had experienced severe floods in 1806. In spite of this, many refused to take advantage of Macquarie’s offer. Those who remained on low ground suffered badly in three severe floods in 1816 and 1817.
Flooding has continued to be a problem for communities along the Hawkesbury River. The region’s worst flood in recorded history, known as “The Great Flood,” occurred in June 1867. Floodwaters covered much of the town of Windsor, resulting in the deaths of at least 12 people. Communities along the river were also affected by severe flooding in 1961, 1964, and 1978. In the early 2020’s, periods of heavy rainfall caused the Hawkesbury to overflow on numerous occasions.
