The O'Shannassy Weir was a small Weir created in 1911 and completed in 1913, and was the originating point of outflow into the Aqueduct. In 1928, it was replaced by the much larger O'Shannassy Reservoir. The Weir had water moving along the Aqueduct to the Surrey Hills Reservoir. Many structures at the Weir precinct have survived and remain in-situ.The O'shannassy Weir and Aqueduct contains a wide range of intact and diverse features. This demonstrates the way in which the Board constructed and managed the water supply that flowed through farmland and forest areas subject to timber milling. The caretakers residences that are located along the aqueduct were utilised by caretakers who were responsible for maintaining one of their four sections of the channel. This transparency is significant for its historic association to the establishment of the weir and to those who worked on the project, and at the quarters. weir, o'shannassy, aqueduct, reservoir, melbourne water, mmbw, staff