No respite from “the Big Dry”.
Graeme Hughes, Fish and Game Officer.

Approximately 2000 salmonid juveniles, Brown and Rainbow trout and Chinook salmon smolts  have been netted or electro fished from drying areas of the Hakataramea River during March and April. The increased flow brought about by rain in February was short lived and  drought conditions returned within  3 weeks. It is presently flowing at 600 litres per second. Perhaps  the longest dry period I have witnessed in 30 years the total numbers of fish rescued and released, over 11000,  is significant and illustrates the production of small tributaries and how important the Haka is to the health of the Waitaki River.  On top of those fish that perish due to lack of water, the numbers of juvenile salmonids, galaxids and bullies lost due mainly to White faced herons, Black shags and to a lesser extent Harriers is significant and despite one irrigator insisting my figures are exaggerated, past experiences have shown that drying shallow pools are meticulously picked clean by flocks of the most efficient of fishers, White faced herons. A disaster for one species is a time of plenty for another.  During the last month the flow has picked up slowly with an increase of 200  litres per second. I wonder if the breaching an illegally constructed weir diverting the flow to a pump intake could have had an influence? Forthcoming legal proceedings may change a level of thinking on their “rights” to take water.

Productive tributaries important to the health of the Waitaki River fishery.
The Waitaki River has three tributaries considered as major spawning grounds for Brown and Rainbow trout. While Brown trout will spawn in the Waitaki River, as far as we know, Rainbow trout do not. Although “Browns” also migrate into tributaries to spawn, the Awakino, Hakataramea and Maerewhenua Rivers appear to be the only spawning waters for “Rainbows” and are vital in maintaining the species. Trapping and tagging migrating rainbows in the past has shown from anglers tag returns that generally the Rainbow trout  caught in the Waitaki River are living in close proximity to the tributaries  in which they spawned.

Most anglers will be aware of the hydro generation and irrigation proposals for the Waitaki River presently under consideration. To many who know the river well, if the proposals become reality it will be a disaster. With 70% of the water diverted for hydro power in the upper river there will be many changes which will affect the habitats for fish and water dependent bird species. Fisheries scientists predict that the residual flow will not support the Rainbow trout fishery we enjoy today.

A prime Waitaki  River “Rainbow”, (4.1 kg) a species which may disappear if the Waitaki river is reduced in flow to satisfy hydro and irrigation demands.

Not only is the “big river” essential to the “Rainbow” fishery their  dependence on tributary spawning grounds compounds management issues. Global warming, dry era, or just too many litres of irrigation water removed from surface flows or groundwater aquifers, small tributaries are becoming smaller and  minimum low flows are becoming the normal day to day flow during the irrigation season.

Non recreational river users have become more conversant and more aware of water use and Fish and Game are receiving more complaints and information regarding water quality and quantity . Recently there has been an emphasis on abstraction which the informants consider contravenes consent conditions. In the last month Fish and Game staff have been alerted to several blatant breaches of consents which demonstrates the selfish nature of a minority which affects many. Information has been received from land owners as well as non abstractive users. The theft of water will not be tolerated and prosecutions are pending. Regional council monitoring and enforcement staff  like  Fish and Game Officers are too few in number to cover all our streams and rivers.  We will respond to all complaints, however accurate and up to date information makes the job much easier. If anglers have genuine concerns regarding abstraction, pollution or modification of rivers and streams contact Fish and Game staff or the Regional Council.

Back to Reel Life