Councillors also added conditional money towards a roundabout at Springs Flat, indicated its support for a new Okara Marina - noting it would consider making a $5 million loan available to the developers subject to financial checks, and added the $600,000 towards the Pohe Island building.
Northland Rugby Union did not make a submission for the $600,000 but three submitters to the Long Term Plan made reference to the council funding the facility.
NRU chief executive Alistair McGinn said the funding allocation was "absolutely outstanding".
"It's something we've been working on for several years. It's an incredible injection for Northland Rugby's growth.
"It gives us a home at last, having rented accommodation for many years."
The council owed Whangarei Old Boys Rugby Club $450,000 as part of an agreement to vacate its site in Okara in 2009 so the land could be sold. That sale was blocked by the Environment Court, and Old Boys have remained on site on a month-to-month lease.
Northland Rugby was asked to move to allow Toll Stadium to be built, and a decision was made for Old Boys and the NRU to go in together and the council would give them the lease of Pohe Island and upgrade the fields.
Progress on the Pohe Island development has been stalled by the high costs of foundation work. Northland Rugby Union approached the council in early 2016 for $850,000 for foundation works but the request was declined.
McGinn said the potential cost of the deep pile foundations escalated to around $1.7m.
A geotechnical report received within the past two weeks came up with a solution where shallow pilings with adjustable jacks for three buildings could be done for around $600,000.
McGinn said the NRU had not made a submission to this Long Term Plan but said the issue "was coming to a head" and he believed with the reception of the new report, council felt it was "a timely investment".
The council has long had $450,000 set aside to contribute towards the building on Pohe Island. The allocation of $600,000 is on top of that, bringing the council's total contribution to the project to $1,500,000.
McGinn said the total cost of the development would be around $3m, but that would be finalised with the designs of the buildings which would include a gym, clubrooms, toilets, a cafe and office space.
He said the NRU would not be seeking any more funding from the council for the building.
"The ongoing financial responsibility will be with Northland Rugby."
A number of councillors referenced the "moral" obligation the council had to help fund the project after its original agreement.
Tricia Cutforth felt it was "really inappropriate for something at this late stage to be lumped in the LTP".
Cutforth, Stu Bell, Cherry Hermon and Anna Murphy voted against the funding.
