New moves to improve Lake Okataina water quality
Tuesday, 23 April 2013 1:45 p.m.
Rotorua Te Arawa Lakes Strategy Group has approved an action plan for Lake Okataina to improve the lake’s water quality.
Bay of Plenty Regional Council will provide information on the lake’s water quality trends to the community and iwi. It will also look into supporting small-scale land use change in future and opportunities for large-scale land use change in the longer term. The University of Waikato will investigate and measure the impact of native bush understory health on water quality.
Lake Okataina is unique in that it has generally good water quality and is surrounded by native bush, but it is not meeting the community’s water quality target because nutrient levels in the lake are too high. Locals have suggested that pest-damaged bush could be one of the reasons.
Scientists estimate the nutrient load needs to be reduced by 860 kg of nitrogen and 380 kg of phosphorous a year to meet this target. A large amount of nitrogen has already been reduced through voluntary land use change, however the phosphorous target has still not been reached.
The Strategy Group released the Draft Lake Okataina Action Plan last October for public feedback. Submitters supported the proposed research and suggested some land use changes to retain more nutrients on the land.
Strategy Group Chairman and Rotorua Mayor Kevin Winters said understanding the difference between phosphorous run-off from pest-damaged and undamaged native bush would indicate how the phosphorous target could best be reached in the future.
“Supporting land use change in the next few years will lead us to meeting the nitrogen reduction target for Lake Okataina,” he said. “Currently very few known and proven opportunities are available to reduce phosphorus in this catchment.”
The community had described Lake Okataina as a unique, tranquil and unspoilt wilderness, highly valued for its historical and cultural significance, as well as prized fishing opportunities.