The power giant, which operates the Waitaki power scheme and Manapouri power station, said national storage was well above average.
‘‘Consistent inflows and careful management of the southern hydro lakes have removed any risk of significant drought this winter,’’ Meridian chief executive Mike Roan said.
‘‘These conditions have also allowed Meridian to maintain solid momentum as we close in on the end of the financial year.’’
Meridian manages about half of New Zealand’s total hydro storage.
On a month-on-month comparison, to June 8, national hydro storage increased from 119% to 125% of historical average.
South Island storage increased to 120% of average and North Island storage decreased to 160% of average at June 8.
Meridian’s May 2026 total inflows were 82% of historical average.
To date this financial year, total inflows were 118% of historical average, the highest financial year to date in inflows since 1998.
Meridian’s Waitaki catchment water storage at the end of May 2026 was 106% of historical average.
Water storage in Meridian’s Waiau catchment was 48% of average at the end of May 2026.
May was a record dry month for many regions, dominated by high pressure and settled weather.
This resulted in a warm month with temperatures above average for much of New Zealand. Rainfall was below normal for much of both islands.
National electricity demand in May 2026 was 1.7% higher than May last year. Excluding the aluminium smelter at Tiwai Point, demand was 0.6% higher than May last year.
The average load for the smelter during May was 576MW, compared with 523MW a year ago, when Meridian and NZ Aluminium Smelter had agreed a 50MW demand response reduction from March to August 2025.
It is early days but snow storage is about normal for this time of year.
Snow melt contributes to water inflows into the Waitaki and Manapouri system in spring and summer.
