Rotoiti lake water best in decades
27 January 2014
Latest test results show Lake Rotoiti's water quality is the best it has been in decades and water quality targets have now been reached.
Bay of Plenty Regional Council General Manager Natural Resource Operations, Warwick Murray, said water quality improvements were a result of interventions through the Rotorua Te Arawa Lakes programme. Rotorua District Council is a partner in the programme along with the regional council and Te Arawa Lakes Trust, with support from the Crown.
The Ohau diversion wall has been extremely successful in improving water quality. This, coupled with sewage reticulation, has meant we have reached the water quality target for the lake, Mr Murray said.
The wall was constructed in 2008 and diverts nutrient rich waters entering Lake Rotoiti from Lake Rotorua. This is allowing us to see improvements in Lake Rotoiti now and gives us the time needed to make the sustainable changes necessary to secure long term water quality improvements, he said.
At the same time we must make sure our interventions don't have any adverse effects on lake ecology or fisheries. We have a fish monitoring programme in place to monitor the long-term effects of the diversion wall on smelt, trout, koura and kakahi.
The latest results from the Fish Monitoring Programme have been very positive, Mr Murray said
Eastern Fish & Game Manager Rob Pitkethley said the start of the current trout season was the best on record since surveys began three seasons before the wall went in and this spring's fishing was a large improvement on the past three seasons.
Trout caught in the channel have been in better condition compared to the last few seasons. Recent highly productive smelt spawning from Lake Rotoiti appears to have translated through the food chain into good trout growth, in both lakes Rotoiti and Rotorua.
The absence of algal blooms and improvements in water quality on both lakes should be beneficial for the longer term health of these fisheries, said Mr Pitkethley.