being completed and officially opened by the Right Honourable Lord Gowrie, Governor of NSW, on 21 November 1936 and a plaque on the northern pier of the dam commemorates the occasion. The Bethanga Bridge was evidently constructed in the middle of this period, probably when water backing-up behind the rising dam wall, began to reach the low level bridge at Bethanga. Three engineers of note were involved in formulating the agreement, Ernest de Burgh, the Chief Engineer of the Water Supply Branch of the NSW Public Works Department, J. S. Detheridge the Commissioner, State Rivers and Water Supply of Victoria, and G. Stewart in South Australia. The initial designs for Hume Dam were prepared by de Burgh and Detheridge. NSW was responsible for construction of the concrete dam and the State Rivers and Water Supply Commission of Victoria was responsible for the southern earth embankments. Another Victorian engineer, Ettore Checchi (1853-1946) was closely connected with the Hume Dam project in the 1920s and 30s. However, as his skills were with hydrographic work, it is unclear what contribution he had to the associated structures such as Bethanga Bridge. The State Rivers and Water supply Commission undertook at least some of the Hume Weir works in conjunction with the NSW Public Works Department. The River Murray Commission evidently had an overriding supervision of the works, but engineering and design details were left to the established public works engineers in the two states. The heavy cost of Victoria's irrigation infrastructure lead to a parliamentary inquiry into the Commission's finances in 1928, and recommendations against further irrigation investment in an era of low export returns from primary produce. However, the Hume scheme appears to have been immune to any cuts due to the State - Federal agreement and advanced stage of the project. The NSW Department of Public Works carried out modifications between 1950 and 1961 to enlarge the dam to about twice its original size to the present capacity of to accommodate diverted water from the Snowy Mountains Scheme. The place As a result of the construction of the weir, the water level in the Murray River backed up behind the dam to permanently inundate the floodplain, which was up to several kilometres wide in many places. Although confirmation of the construction authority is yet to be found, there is later evidence in the form of lantern slides showing the construction of the