Miena Dam No. 2, Shannon River
Background
This dam is located at the outlet of the Great Lake in the central highlands of Tasmania. It replaced the original 4m high masonry dam built in 1916. Miena Dam No 2 was built in 1922 to increase the storage level of the lake and control the outflow to Waddamana A Power Station 15km downstream, enabling the capacity of the power station to be substantially increased.
This multiple arch concrete buttress dam is 360m long, 27m high and has 27 arches. The dam type was chosen to minimise the quantity of concrete required. Cement was in short supply and was imported from five different countries.
The dam was constructed in difficult conditions; in the winter of 1918 the lake froze over and work was halted. The storage level was raised by 6m.
Subsequent History
Miena Dam No.2 served its purpose until 1967 when the Great Lake North power development was completed, taking the water to the new Poatina Power Station. The Waddamana power stations were closed down.
A higher rockfill dam was constructed immediately downstream in 1967 to increase the storage available to the new power station. Consequently, Miena Dam No.2 disappears from view when the lake level is up and periodically reappears when the lake level falls. The dam remains in good condition apart from frost damage to the parapet.
Engineering Heritage Recognition Program
| Marker Type | Heritage Engineering Marker (HEM) |
| Award Date | March 2001 |
| Heritage Significance | Second longest multiple arch Buttress Dam in the world when completed in 1922
Created to regulate the flow of water to Waddamana power station. |
| Nomination Document | Nomination document |
| Interpretation Panel | Interpretation panel |
