The large pastoral dam at 625-833 Holden Road, Plumpton is significant as a probable Clarke Rockbank estate dam - one of a unique series known in Victoria - and also as the best example of a more typical style of nineteenth century dam of the Melton plains area, where water management was an especially critical issue.
The large pastoral dam at 625-833 Holden Road, Plumpton is structurally significant at the LOCAL level (AHC D2) as a large and relatively intact example of a nineteenth century building form in the Shire of Melton. Its use of fieldstone or floaters as shoring on the dam wall is typical of the dams built by many smaller pastoralists and farmers in the Shire, and contrasts with the more professionally built walls on other Clarke dams. This use of the rocks may also have been a form of 'consumption' or use of the fieldstones.
The large pastoral dam at 625-833 Holden Road, Plumpton is historically significant at the LOCAL level. (AHC B2) It represents a building form that is no longer generally practised and in danger of being lost in the Shire of Melton. It is expressive of the importance of water management in the Shire of Melton, whose especially low rainfall has been a major influence in its history.
Its likely origin, as one of a series of at least four large and medium sized drystone dams to have been built on the Clarkes' Rockbank station in the Shire of Melton, is also of historical significance. No comparable structure or group of structures, comprising long stone dam walls over wide shallow gullies, is known elsewhere in Victoria. These structures were a local response to the particularly low rainfall of the plains area, the difficulty of sinking 'tank' dams in the shallow bedrock of the area, and the local availability of bluestone. Smaller Melton pastoralists and farmers constructed much smaller and more makeshift dams which were also variations on the same principle. The dam is also significant for its likely association with Australia's mid nineteenth century pastoral giant WJT Clarke, and his son Sir WJT Clarke, Victoria's leading citizen in the late nineteenth century, and Australia's first baronet. As such, the dam would have been integral to the 40,000 acre Rockbank station's role in fattening and delivery of sheep for the Newmarket meat trade. With the other Clarke dams, it conveys something of the scale of the Rockbank station, whose domination of the Melton Shire was an increasingly acute grievance to local farmers, culminating in the break-up of the estate in the early twentieth century.
Overall, the large pastoral dam at 625-833 Holden Road, Plumpton is of LOCAL significance.