Hydro Lakes in Serious Decline

Hydro lake storage declined to low levels during November 2007, ending the month lower than levels recorded at the same time in 2004, 2006 and the crisis year 1992.

New Zealand’s hydro-electric storage lakes stood at 2516 GWh (GigaWatt hours) 103% of the average for the time of year at the beginning of November 2007. As the month progressed, they declined steadily, ending the month at 80% of average, 2103 GWh.

Storage measured on a daily basis was above last year’s values until the 9th, and it then plunged below last year’s figures on the 11th. The decline continued to the month’s end, passing below 2004 and 1992 storage levels mid-month, but remained above 2005 levels as the month closed.

Inflows were erratic, and daily figures were only above average on 1 day. From November 6th, inflows were 77% of average or lower as dry spring conditions set in to many catchments.

Demand was greater than last November’s daily demand on 29 days and peaked at 112.3 GWh on November 6th. Last year’s November peak load of 110.6 GWh was recorded on the 8th. The average daily load during November 2007 was 105.2 GWh.

South-to-north transfers via the Cook Strait cables exceeded north-to-south transfers on 29 days.

[Compiled from data supplied by M-co.]

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