the river were the Eora and Guringai people. Australian history since colonisation In 1789 two expeditions explored the Hawkesbury to the northwest of Sydney and the Nepean River to the southwest. It took about three years to realise they had discovered the same river system. Hawkesbury River was one of the pivotal positions of the Hawkesbury and Nepean Wars, a series of skirmishes and battles between the Kingdom of Great Britain and the resisting Indigenous clans that took place between late 1780s and late 1810s. The Hawkesbury River was one of the major transportation routes for transporting food from the surrounding area to Sydney during the 1800s. Boats would wait in the protection of Broken Bay and Pittwater, until favourable weather allowed them to make the ocean journey to Sydney Heads. With the opening of the railway from Sydney to Windsor in 1864, farm produce could be shipped upriver for onward transportation by train. However, by the 1880s the river had become silted up between Sackville and Windsor, and Sackville became the head of navigation for sea-going vessels. Until the end of the 19th century coastal steamers linked Sackville to Sydney. The Hawkesbury River was given its present name by Governor Phillip in June 1789, after Charles Jenkinson, 1st Earl of Liverpool, who at that time was titled Baron Hawkesbury, after the Cotswolds village of Hawkesbury Upton in England, where the Jenkinsons still live. An obelisk was unveiled in 1939 at Brooklyn to commemorate the naming. In 1794, 22 families were granted land at Bardenarang, now known as Pitt Town Bottoms, near Windsor. In that same year, confrontations between Aboriginal people and settlers broke out. Controversy Raising of Warragamba Dam In May 2017, the New South Wales state government released the Hawkesbury-Nepean Valley Flood Risk Management Strategy, that proposed raising the height of Warragamba Dam by an additional 17 metres, using the Climate Change Mitigation Fund. It was claimed that this would reduce the risk of flooding to homes downstream along the Hawkesbury-Nepean river, that is the most at-risk region of Australia to devastating flooding, exacerbated by Global Warming. A large public opposition campaign culminating in the GIVE A DAM movement began to protect the ecological, historical and Indigenous heritage of the additional area prone to flooding due to the raising of the dam wall. A significant portion of the land to be inundated is located within the Blue Mountains