Opuha near low record

18:59, Nov 06 2014
Low levels of Lake Opuha
Concerns have been raised over the low levels of Lake Opuha which is now down 27 per cent of its usual level for this time of year

Lake Opuha's water level is down 27 per cent on its usual level for this time of year and is still dropping steadily.

Opuha Water Limited (OWL) chief executive Tony McCormick said his company had been "on watch" since August and although there are no water restrictions in place as yet, they could be on the way.

As of yesterday, the water level sat "well below average" at 66 per cent, its second lowest November level since operations began in 1998. At this time of the year it normally is 91 per cent full.

The lake received more water than usual in September and was well above average by the end of that month.

The drop in levels during October came about due to low rainfall and snow melt, which lake levels usually benefited from at this time of year.

This, combined with the early start to the irrigation season, saw lake levels draw down steadily over October.


OWL, as a part of consultative group Opuha Environmental Flow Release Advisory Group (OEFRAG), met late yesterday to consider what response was required to low storage conditions.

Representatives from district councils, Federated Farmers, Fish and Game, Forest and Bird, Arowhenua Runanga and OWL make up OEFRAG.

The company is advising irrigators to carefully consider their water use.

Once the lake reached a "trigger" level of 50 per cent, the group could apply to Environment Canterbury to order a water shortage directive (WSD); the last time that occurred was in October 2011, despite coming close last year. Such a directive can impose water restrictions on irrigators.

McCormick said although they were concerned, he did not believe it had reached the "critical" stage.


A South Canterbury dairy farmer says milk production is "in the hands of the gods" as the Opuha irrigation dam falls below its seasonal average.

Opuha Water Limited revealed in its November newsletter the dam was close to a third below its average for this time of year and on a "continuing downward trajectory" that was "opposite to our usual experience".

Hazelburn farmer Brent Isbister remained optimistic that enough rain could fall before Christmas to save farmers dependent on the Opuha scheme from cutting production or buying stock feed.

"History would show if it's full by Christmas the irrigation season will be alright."

Isbister believed farmers had "lots of options" if the rain failed to come, although "most of them either cost money or milk production".

Such actions were likely to have flow-on effects throughout the region.

South Canterbury Federated Farmers President Ivon Hurst believed Opuha Water was "walking on a bit of a knife edge at the moment". He believed the company were "edge-cutting" water managers, but the season could test the flexibility of their system.

Hurst hoped for significant rainfall soon to maintain soil moisture.

"We need a good two inches [50mm] of water straight up bang."

The Seasonal Climate Outlook released by The National Institute for Water and Atmospheric Research (NIWA) for November to January predicts a 50 per cent chance of below average river flows and soil moisture in the eastern South Island. NIWA's monthly climate summaries indicate its monitoring sites received below average rainfall in September and October.

The Timaru Herald