Lower Stony Creek Dam, located 40km out of Melbourne in the Brisbane Ranges National Park, is the world's third oldest concrete dam and the oldest in Australia. 

Standing 16m high and measuring 69m across, the dam has a storage capacity of 630 million litres. It cost £17,000 to build and an extra £12,000 was spent on a new water pipe to transport water to Geelong.

Newly appointed Chief Engineer for Water Supply George Gordon and Resident Engineer Edward Dobson were the driving forces behind the new dam. Dobson, who had the greatest experience in field construction, strongly recommended the dam be built with Portland cement.

At the time of the dam's construction in 1872, Portland cement was far from the popular construction material it is today. It was developed in Britain between 1820-1850, when manufacturers attempted to produce hydraulic cement to replace the Roman cement and Hydraulic lime. By 1850, Portland cement had become a distinguishable product from hydraulic lime and Roman cement; however, manufacturers were still trying to make a consistent product. For that reason,  Portland cement was more expensive than other products available.

The engineers' decision to use the unusual material was considered a remarkable step forward for British and Australian engineers and helped pave the way for the cement's use. At the time, the only other concrete dams in existence were Boyds Corner Dam in the US and Lac de Perolles Dam in Switzerland, both of which were constructed in 1872.

As an experienced engineer who had studied and worked across Europe, Chief Engineer Gordon designed the dam profile based on theoretical developments in the field. The dam was designed in line with respected Scottish mechanical engineer Professor William J M Rankine's recommendations, which included designing the dam wall with a horizontal curvature to avoid any horizontal tension in the air face.

Accordingly, the Lower Stony Creek Dam wall is curved toward the reservoir, with a radius of 91.4m. With this feature, the dam can also lay claim to being one of the first dams to follow current design principles based on stability and economy. Previously, dams were designed by craftsmen engineers who had little knowledge of stability analysis.

For 125 years, the Lower Stony Creek Dam gave Geelong its first reliable water supply, essential for the area's economic growth, public health and protection from fire. In recognition of the dam's historical, social and engineering significance, Engineering Heritage Victoria successfully nominated for it to be a awarded an Engineering Heritage National Marker.

You can join the heritage marking ceremony by registering for the Victorian Engineers Country Weekend which will be held 16,17,18 November.