The work, which was four years in progress, was commenced on the 20th December, 1853, when Lieutenant-Governor Latrobe turned the first sod. The official ceremony of turning on the water was effected by Acting-Governor Major-General Macarthur, 31st December, 1857, and from New Year's day, 1858, the formal opening may be dated. On its completion the total cost of the Yan Yean was £664,452, and £90,606 had been expended on works of temporary supply. The embankment was 3159 feet long, 31 feet high at its highest point, 170 feet in width at the bottom, 20 feet at top, with slopes of two to one towards the land, and three to one to the water. Its supposed containing capacity was 6,500,000,000 gallons, or something more than a three years' supply for 200,000 persons at the rate of 30 gallons each per diem. This quantity of water was to be supplied from the rainfall over an area of 4600 acres, exclusive of the reservoir, the drainage of 600 acres through a water-course connecting the Plenty River and the Lake, and some 40,000 acres, comprising what was known as the Valley of the Plenty. The Plenty River was linked to the reservoir by a 440 yard tunnel through a hill, and then by an open cut from the stream. The water in the Yan Yean, at the highest level, stood 600 feet above high tide in the Yarra, and was conveyed to Melbourne by 19 miles of piping, the pressure in which was reduced by several valves. With all its shortcomings and capriciousness in the quality and quantity of the fluid it supplied, it has been both the best abused and most generally useful public servant the City of Melbourne ever had, and, as the first great public work constructed in Victoria, is a remarkable example of judiciously-directed enterprise.
