Southern hydro lake levels expected to rise
Waitaki hydro lakes are unlikely to drop below their minimum consented levels despite a run of warm weather, power providers say.
They expect the lakes to rise when snow in the mountains melts with the arrival of spring in a few weeks.
Several days of warm weather is forecast as the region moves away from the overnight freezing temperatures of the past few weeks to a temperate weather system from Australia.
A Meridian Energy spokeswoman said since February, Meridian had recorded low inflows to its Waitaki Hydro Scheme catchment, which meant lake levels were low.
According to Meridian Energy, Lake Ohau was at 519.84m, just above the minimum of 519.45m, Lake Pukaki at 523.316m (518m), Lake Aviemore at 268.028m (265.5m), Lake Waitaki at 230.095 (227m), and Lake Benmore at 361.209 (355.25m)..
Lake levels had been managed prudently and would be extremely unlikely to breach minimum consented levels, the spokeswoman said.
‘‘Small rainfall events over the last week and a half have halted the decline in our hydro lakes.
‘‘We have seen a slight lift in lake levels and we are continuing to get small inflows.
‘‘Typically in spring inflows increase as snow in the Southern Alps melts and enters the hydro catchments.’’
Transpower, the system operator which monitors the hydro risk level, showed the inflows to the southern hydro lakes had shifted the level from ‘‘watch’’ to ‘‘normal’’.
Genesis Energy, which measures the levels for Lake Tekapo – the feeder to the Tekapo A and B power stations – showed the lake was at 705m, above the minimum level of 702.1m.
A Genesis spokesman said in ‘‘broad terms’’ Lake Tekapo was lower than average but he expected levels to rise as snow melted.
Lake Tekapo’s level had risen by about 30cm on Tuesday, he said.
The spokesman could not comment on the consequences if the lake dropped below the minimum consented level.