Rydal DamOur smallest dam, generating power for NSW

Status Open to Public

Visit the Dam

Rydal Dam stores water for power stations at Wallerawang and Mount Piper. The dam is part of the Fish River water supply, the only scheme in eastern Australian 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 to nearby power stations as well as meeting stock and domestic needs in the Oberon and Lithgow areas as well as the Blue Mountains.

Look out points

Views of the dam and lake are available from nearby bush tracks.


Opening hours

Dam grounds

Open 24 hours a day, all year round. Entry is free.


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:


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

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 14,000 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.

For more information on the building of Rydal Dam.

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.


Dam Summary

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

Dam Wall

Size Measurement
Length 425m
Thickness of base m
Width of central spillway m
Concrete mass t
Width of auxillary spillway m
Length of auxillary spillway m

Lake and Catchment

Size Measurement
Area 1km2
Length of lake km
Length of foreshores km
Maximum depth of reservoir m
Catchment area 2km2
Annual average rainfall mm


Size Measurement
Diameter mm
Length km each
Capacity ML per day
Sunday 29 November
2,371,296 ML
2,581,850 ML
7,838 ML
1,120 ML
-101,020 ML
Sunday 29 November