Testing of Lake Aviemore, which could see it rise and fall within maximum and minimum levels, has again been postponed by Meridian Energy Ltd as it copes with the demand for electricity in freezing weather.
The company had planned to carry out the tests, part of upgrading the Aviemore power station, in May, but postponed them until this month after heavy rain along the Southern Alps raised storage lake levels.
However, they have been postponed again until the last quarter of this year - some time between October and December.
A Meridian spokesman said yesterday the delay was to minimise effects on the generation market and manage storage.
The level of Lake Aviemore could fluctuate by about 3m during the tests as part of an upgrade of the power station's control system.
The tests are needed to get accurate data for a new programmable logic controller, a digital computer that controls the Aviemore power house generating units.
The testing will cover the full operating range of Lake Aviemore, from 267.7m above sea level to 268.3m, one test dropping 2.65m from its maximum level.
Lake Waitaki may also be affected.
Meridian said changing lake levels posed no operational or public safety issues, although the lower sections of some Aviemore boat ramps may become exposed for one day, which could affect boat owners wanting to launch.
However, the low lake level also gave the chance for repairs to ramps.
