Divers brave icy alpine waters to replace Oberon Dam valves

The works will not impact the operation of the dam or access to nearby recreational facilities. However, there may be slight loss in water pressure and water discolouration during this period for some customers.

Public pedestrian access along the Oberon Dam wall will be closed for the safety of visitors and workers.

Specialist divers will replace several valves on the intake tower that control the release of water from the dam as part of WaterNSW’s Fish River supply scheme that supplies Oberon and Lithgow councils.

“The current water temperature is a chilly eight degrees, but these specialist divers wear dry suits and do this kind of work year-round,” WaterNSW General Manager Regional Operations Sydney, Brian Mayhew, said.

“It’s actually safer and more cost-effective to use divers to replace the valves rather than lowering the lake’s water level.”

A temporary pumping system will first be installed to pump water over the dam wall and into the pipe system, to ensure an essential supply of water to Fish River customers. Water usually flows by gravity alone through the valves into the supply system.

Divers will then start replacing a series of valves along a vertical section of the intake tower. Each valve weighs about 400kg and are 675mm wide and 1,500mm high.

The Oberon Dam valve replacement works start at the end of July and will take about five weeks to complete, weather permitting.

“The work will help ensure the reliable and efficient operation of the Oberon Dam intake tower and safe water supply to customers in the Fish River region,” Brian said.

WaterNSW will closely monitor the quality of water to affected customers during this time. WaterNSW does not expect any interruption to supply for Fish River customers.

“To minimise impacts to the community and customers, this essential maintenance work is completed during winter when demand for water is lower,” Brian said.

“WaterNSW invests in regular maintenance and upkeep to ensure the reliability of our assets into the future and provide the best outcomes for our customers.”

Oberon Dam is situated on the Fish River about three kilometres south of Oberon on the NSW Central Tablelands, about 190 kilometres west of Sydney. At 1068 metres above sea level, Lake Oberon is classed as alpine waters.

The Fish River water supply scheme supplies water to Mount Piper power station, to Oberon and Lithgow councils for domestic and industry use, and to about 230 properties along its length. It also supplements town supplies in the upper Blue Mountains.