DARTMOUTH Dam is unlikely to cascade over the spillway this year, despite being within 60 centimetres of overflowing.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
Only a massive downpour of 40,000 megalitres within the next week or so could tip water over the concrete spillway.
Weir keeper Peter Liepkalns yesterday said the Murray Darling Basin Commission’s strategy was to keep a 60-centimetre buffer this year before the dam level declined.
“It’s very unlikely to spill now, but next year the chances would be good if there’s enough rain,” he said.
Click play to press the video (iPhone app users can press the 'Videos' tab).
With the dam now at 99 per cent for the first time in 16 years, locals still expect a flood — of tourists viewing a lake covering 6380 hectares and holding 6.5 times the volume of Sydney
Harbour.
Such a spectacular sight hasn’t been enjoyed since 1996.
The good news for AGL Hydro is that its hydro power station at the dam is generating 175 megawatts for the national grid as 3000 megalitres a day rushes through Australia’s biggest hydro turbine.
If the dam were to spill, generation must stop in order to limit flows to the Mitta valley.
Mr Liepkalns works for Goulburn Murray Water, which operates the dam as agent for the Murray Darling Commission.
The hydro operation
is privately owned by AGL.
He has worked at the dam site since 1979, the year the 180-metre high dam was commissioned.
“It has spilled only six times,” he said.
“The first time was on July 24, 1990, although it came within centimetres of spilling in 1989.
“It spilled twice again in 1990, then in 1992 and 1993 and in October-November, 1996.”
Releases were yesterday increased to 3000 megalitres a day, the water being channelled in a tunnel from the high-level intake at 424 metres above sea level to the power station at 328 metres.
The flow should be lowered to 2000 megalitres next week with little rain forecast in the meantime.
The intake is about 61 metres below today’s surface level of 485.4 metres above sea level. The temperature of the released water is about 12 degrees.
Mr Liepkalns said the deepest part of the dam was about 165 metres.
Water comes out of the power station at the rate of 145 cubic metres a
second.
The Mitta River is protected by three control dams below the main structure. The Banimboola dam holding back a pondage also generates a little power.
Power is transferred from the station via a
220-kilovault line to Mount Beauty.
