Rydal Dam Our smallest dam, generating power for NSW

Rydal Dam
Status Closed to Public
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Visit the Dam


Rydal Dam is part of the Fish River water supply, the only scheme in eastern Australia to transfer western flowing water east of the Great Dividing Range. Conceived in the 1940s to supply water to the shale oil industry, the scheme now supplies water for the power station at Mount Piper and other villages in the area, as well as meeting stock and domestic needs in the Oberon, Lithgow and Blue Mountains areas.

Opening hours

Rydal Dam is not open for public access.


View in Maps

Rydal Dam is 2 kilometres north of Rydal and about 20 kilometres west of Lithgow on the NSW Central Tablelands. Rydal is about 170 kilometres west of Sydney via the Great Western Highway and Old Western Road.




Restrictions are in place to protect our water supply and ensure that everyone has an enjoyable and safe visit - with penalties up to $44,000 applying:

  • No model aircraft or drones

Recreation Areas at WaterNSW dams will be closed on ALL Total Fire Ban days.

Dam Summary

Metres High
Length: 425 metres
Size of lake:
1 km 2
0.37 gl total operating capacity
Catchment: 2 square kilometres

Facts & History

Rydal Dam is about 2 kilometres north of Rydal and about 20 kilometres west of Lithgow on the NSW Central Tablelands. The dam is about 170 kilometres west of Sydney.

Rydal Dam has a capacity of 370 megalitres. Water is transferred to the dam by pipeline from the Fish River water supply scheme at Oberon for supply to nearby power stations.

Why the dam was built

The Fish River water supply scheme has its origins in chronic water supply problems in the towns of Lithgow, Wallerawang, Portland and Oberon as early as 1937, which were exacerbated by the 1940s drought. Small local schemes were rejected in favour of a regional scheme but funding delays stopped the start of works.

World War II and the need for Australian-sourced fuel re-started the project in 1943 with an expanded scope to include water supply to the Glen Davis shale oil works. The early 1950s saw the closure of the shale oil works but the creation of new power stations for electricity generation at Wallerawang.

Today the scheme supplies water to Wallerawang and Mount Piper power stations, to Oberon and Lithgow councils for domestic and industry use, and to more than 200 landholders along its length. It also supplements town supplies in the upper Blue Mountains.

How the dam was built

Rydal Dam is an earth-fill embankment with an uncontrolled channel spillway just to the south. The dam wall is 425 metres long and 16 metres high.

The dam was built as part of an expansion of the Fish River water supply scheme between 1954 and 1959 which included a new 54 kilometre long pipeline from Oberon Dam to Wallerawang to increase water supply to the power stations.

Rydal Dam was built to ensure reliability of water supply to the power stations. Work on the dam started in 1956 and finished in 1957.

Later improvements

To meet modern dam safety standards, in 1996 a fuse plug spillway was built to divert floodwaters around the dam in a rare and extreme flood so as to protect the dam and ensure it remains safe in an extreme flood. The dam’s spillway channel had earlier been widened in 1989.


In consultation with our stakeholders and the community we review and update these notifications.

To receive Early Warning Network notifications below please register your details with us.

To see past notifications, please visit all dam notifications.

Dam safety notifications

Alerts will be issued in the following unlikely events:

  • When there is a reasonable possibility of dam failure.
  • State Emergency Service (SES) require advance public warning to evacuate if such a failure may occur.

Amber alert

  • Trigger - Storage level is 600mm from embankment crest.
  • Notification - You are advised to move to higher ground and if necessary evacuate.

Red alert

  • Trigger - Storage level has reached embankment crest level.
  • Notification - Residents are advised to evacuate to their designated flood assembly points.

Flood notifications

Flood notifications indicate the dam is releasing controlled or uncontrolled flows, likely to cause downstream flooding.

There are no flood notifications at Rydal dam

High regulated releases

High regulated releases are when our operations may impact landholders immediately downstream or we are releasing higher than normal flows.

There are no high regulated releases at Rydal dam

More information

Bureau of Meteorology Weather forecasts and warnings BOM varies by region
NSW State Emergency Service Flood or severe weather warnings/advice NSW SES 132 500
NSW Water Information Storage levels and river heights Water info N/A
WaterNSW Algae Hotline Algal alert details and algae levels WaterNSW 1800 999 457
Early Warning Network To view or edit your registration details EWN 1300 662 077


Saturday 25 June
2,524,148 ML
2,618,706 ML
9,094 ML
1,300 ML
27,516 ML
Saturday 25 June