A Cabinet decision to reallocate $24 million in Government funding has meant a critical part of the programme can go ahead - a $48 million incentive scheme for affected landowners.
Approval from the Government was required as the re-allocation was a change to the deed funding agreement which saw the Crown contribute half of the $144 million needed to help restore four priority lakes in the region.
Doug Leeder, chairman of the Bay of Plenty Regional Council, one of three partner bodies of the Rotorua Te Arawa Lakes Programme, described the decision as a "significant milestone".
Rotorua Te Arawa Lakes Strategy Group chairman Sir Toby Curtis said the move would progress a scheme that would ultimately help achieve the community's aspirations for the lake.
"Water quality in Lake Rotorua is improving but the challenge now is sustaining that improvement in the long term and that's the aim of the rules and incentives scheme," he said.
"It is very pleasing that the Government is supporting our approach."
Rotorua Mayor Steve Chadwick also welcomed the decision.
"This is great news and a relief to have the decision now, ahead of the elections," she said.
"The lakes programme is hugely important both for our local community and nationally, and we want to do whatever we can to help our landowners make the changes necessary to achieve our goals for Lake Rotorua.
"It will provide more support for farmers to seek solutions for land use change."
Six years earlier, the Government agreed to contribute $72 million to implement the Rotorua Te Arawa Lakes Programme, with the other half of funding coming from Rotorua District Council and Bay of Plenty Regional Council.
The programme aims to restore four priority lakes - Rotorua, Rotoiti, Okareka and Rotoehu - and sets out a range of measures to curb nutrient loading into the lake.
Interventions have included improved sewerage reticulation, sewerage plant upgrades, floating wetlands and a treatment plant for geothermal nitrogen that will reduce the nitrogen load in Lake Rotorua by an estimated 50 tonnes a year. This left an annual balance of 270 tonnes to be reduced from the pastoral sector to achieve the 320 tonne reduction target, and it is proposed this will be done by improvements and change in land use, along with re-vegetation of areas of gorse, which leach nitrogen.
Tense debate over the lake's health and how it should be cleaned up created divisions between authorities, farmers and environmental groups, before parties sat down for talks in 2011.
The resulting Waiora Agreement allowed the two groups to work through a list of sticking points, including stock movement in the catchment, management of erosion and sediment control, and other mitigation strategies such as wintering barns and biogas production.
But farmers could still not accept a regional council regulation requiring the nitrogen load into the lake to be cut by more than 300 tonnes to a sustainable level within a decade.
For some farmers, especially drystock farmers who had been struggling for years, the requirement would have put them out of business.
Rotorua MP Todd McClay again intervened, and a landmark deal was struck, pushing the deadline back to 2032 but still requiring a 70 per cent reduction within a decade.
After signing the agreement, Federated Farmers dropped an Environment Court challenge against the regional council.
