Hydrological summary as at 13 May 2001
Lakes Lake level (m) % Full Minimum operating level Maximum operating level
Taupo 356.2 31% 355.9 357.1
Tekapo 707.5 63% 702.1 710.6
Pukaki 527.2 63% 518.2 532.5
Ohau 519.9 18% 519.8 520.3
Hawea 340.7 34% 338.0 346.0
Wanaka (uncontrolled) 276.6 27% 276.4 277.0
Wakatipu (uncontrolled) 309.5 15% 309.4 310.0
Te Anau 201.2 18% 200.9 202.7
Manapouri 176.8 34% 175.9 178.6
Sources: M-co, NIWA
Lakes Tekapo and Pukaki represent almost 60% of New Zealand’s total storage capacity for hydro-electric generation. At
week’s end, national storage was at 2,020 GW/h, 68% of the average for this time of the year. National inflows for the
last seven days were 50% of the average.
Changes to the M-co EPI
Currently the M-co EPI is calculated for each region using the average price from four regionally representative points
(or ‘nodes’[*]). It is calculated using information from every period of the seven days up to and including the index
date. This calculation is weighted by the demand at all nodes in the region.
To further enhance the accuracy of the index, from Sunday 13 May 2001, M-co will calculate the EPI using price and
demand information at all nodes within the region (as opposed to prices from the regionally representative points and
demand at all nodes in the region).
The new calculations will mean prices from 1 March 2001 alter very slightly from those originally released. If you use
previously released EPI information, please ensure you replace the indices from 1 March onwards with the attached
figures.
[*] A ‘node’ is a designated point of connection to the National Grid. It can be either a grid injection point, where
generators input electricity, or a grid exit point, where retailers or direct consumers are supplied with electricity.
The New Zealand Electricity Market records prices at around 250 nodes.
-ends-