Stage 5: Environmental regulation (1905–1950) Evidence Parliamentary Acts and inquiries, alongside newspaper reports, reveal that initially the regulatory approach to managing sludge was to move it elsewhere, such as via channels to larger streams. Mining claims were also protected by constructing infrastructure so that the sludge did not halt mining activities. Later legislation attempted to deal with the sludge at source, penalising miners for polluting channels (Lawrence and Davies 2014). The Mines Act of 1904, and its amendment in 1907, led to the creation of the Sludge Abatement Board (SAB). Inspectors from the SAB could impose fines for polluting waterways. The detention of sludge near to its source and its stacking at mine sites were some of the consequences of this change in legislation. Sludge dams were built around mine sites, changing the landscape of many tributaries and resulting in localised accumulation of fines either in channels or close by. On Hodgsons Creek these sludge dams are recorded in early maps, and can be seen in the current LiDAR imagery. It is easy to see them by using a slope layer derived from the DTM as they are flat surfaces on the landscape (Figure 13). They are estimated to contain up to 0.3 million m3 of sediment. Whilst some detention dams were used as a terminal store for sediment, there are records to suggest that some were flushed during high flows, when inspectors would be unable to detect Figure 11.  The estimated surface changes a result of mining in the 3 Mile Creek valley, negative numbers are erosion and positive are deposition. (source: Department of Environment, Land, Water and Planning). Figure 12.  An example of primary mining at the Jim-Crow Diggings showing the mullock heaps and the disturbance to the river channel (source: State Library of Victoria) Feature Mining to mud 51 PREVIEW JUNE 2019