Last year it was too much water, this year it may not be enough to trap salmon in the Hakataramea River as part of ongoing efforts to improve the Waitaki River fishery.
The Waitaki Riparian Enhancement Society has a salmon hatchery and rearing ponds on the Waitaki River with a capacity of up to 50,000 smolt, but in recent years a number of factors have affected releases.
Last year, the society started with 35,000 to 40,000 fry but, because of various problems, only released about 1100.
This year, the society is raising about 17,000 in its rearing pens at Bell's Pond after floods in the Hakataramea River last year severely hit the number of fish it trapped.
This year, society secretary Linn Koevoet said, it could be the drought conditions that affect trapping, with part of the lower Hakataramea dry about 200m below the trap site, close to the confluence with the Waitaki River where the salmon come from.
Lower flows and warm water from the Hakataramea River would deter salmon entering.
The society is aiming to set up a new purpose-built trap on April 18, and is looking for volunteers to man it on 24 hour rosters from 8am each day.
The fish in the rearing raceway have reached an average weight of almost 40g, with an average of at least 100g needed before the release late next month or in May.
The society has a fin-clipping day, so returning salmon can be identified as coming from its hatchery, on April 5 from 10am.
''Two years ago we had 80 people do this, but this year we will need ... [slightly more],'' he said.
