A purpose-built ornamental lake was part of Walter Burley Griffin’s original design for Canberra. The lake 'served to unify and crystallise the entire concept of the national capital’. Before filling the lake, a working model was created to examine water flows, including what might happen during flood conditions. Bridges and dams were completed by September 1963 but a drought meant that the target water level was not reached until April 1964. It was formally inaugurated on 17 October 1964 by Sir Robert Menzies.