Tide turning in Lake Rotorua

Regional council representatives believe the struggle against Lake Rotorua’s deteriorating water quality is being won.

The Rotorua Lakes Protection and Restoration Programme – a partnership of Bay of Plenty Regional Council, Rotorua District Council and Te Arawa Lakes Trust - has stopped water quality declining in Lake Rotorua.

Last year the lakes had the best water quality since the 1990s.

It has mostly been achieved through in-lake interventions and favourable climate conditions, says Bay of Plenty Regional Council general manager of natural resource operations, Warwick Murray.

“These results are great to see, but the way land is used in the catchment needs to change if we are going to achieve long-term sustainable water quality gains.”

Water quality is affected by nutrients entering the lakes from a range of natural sources and human activities. Currently 70 per cent of nitrogen entering the lake comes from agriculture.

“Our previous activities focused on treating nutrients in the lake, and this has provided great short-term benefits. To reach long-term sustainable targets, the way we use the land needs to change. We need to stop the nutrients entering the lake. We need to turn off the nutrient tap up in the catchment.”

Nitrogen entering the lake needs to be reduced by 320 tonne per year, says Warwick. To achieve this target an integrated approach of rules and incentives will be used, and farmers and landowners in the catchment need to be involved.

“To ensure a fair and equitable approach it is important that we work with those affected by our decisions. We need to reduce the impact that farming has on lake water quality through both best farm practice and land use change. To do this we need buy-in from farmers and to include them in the process,” says Warwick.

New rules will be used to allocate the sustainable nutrient load of 435 tonnes and to ensure that this limit is met. An incentive scheme will be designed to help reduce the impact of the rules and enable farmers to make necessary changes to their operations.

A workshop in August with more than 80 key stakeholders agreed that a small nominated group should work directly with council.

The group includes 12-15 members from the Lake Rotorua Primary Producers Collective, Lakes Water Quality Society, Bay of Plenty Regional Council, Rotorua District Council, Te Arawa Lakes Trust, Office of the Māori Trustee, the forestry sector, iwi landowners and small block owners.
“The group will provide oversight, advice and recommendations on both the rules and incentives,” says Warwick.

The advisory group will meet regularly to share their views, knowledge and expertise. Other stakeholders, affected individuals and the broader Rotorua community will also be consulted.

“Getting sustainable improvements in water quality in Lake Rotorua will take time,” says Warwick. “It took 50 years to create the problem, and it will take time to fix it. Between our incentive fund and our rules we can reach the water quality targets set by the community for Lake Rotorua.”