Junction Reefs Dam
Gold was discovered in 1870 by Martin Sheahan where the Mandurama Ponds creek meets the Belubula River, some 7km northwest of Lyndhurst in NSW; soon after mining companies were formed. To supply water for its crushers and electricity to power the crushers and mills, Lyndhurst Goldfields Ltd which had consolidated various gold mining claims, built a dam and a hydropower installation.
The dam is a concrete-brick multiple arch buttress dam, 131m long with a maximum height of 18.3m. There are five elliptical arches with an 8.5m span each and a 60o lean supported by six arch shaped buttresses. The foundations and outside walls are made of concrete while the arches and buttresses are of locally fired clay bricks. The original storage capacity was around 2,500ML but is now substantially silted. The dam was equipped with a large scour outlet system and a pipe outlet to supply the Pelton turbines some 1.5km downstream.
The designer Oscar Schulze, was a visionary who appreciated the value of alternative energy sources and was strong willed enough to proceed with his ideas even though criticised by his fellow engineers. He had a substantial input to various major engineering structures during his working life in NSW including the first railway bridge crossing of the Hawkesbury River.
Junction Reefs is significant as being the first multi-arched dam built in Australia and for its predominantly hand-made brick work construction.
Engineering Heritage Recognition Program
| Marker Type | Engineering Heritage National Marker (EHNM) |
| Award Date | February 2008 |
| Heritage Significance | Junction Reefs Dam was a very early use of water power to drive a mill to recover gold. |
| Nomination Document | Available here. |
| Ceremony Booklet | Not Available. |
| Plaque/Interpretation Panel | None Installed. |
