The "osmotic" effect that Auckland's growth would have on Northland would see the region's industrial employment soar from 9088 in 2013 to 13,411 in 2031, through the use of an additional 935.5ha.
While the largest demands for additional land would come from heavy industry (+423.6ha), the employment growth would stem from light industry land growth (+212.7ha) and noxious industry (+201.1ha).
The report stated that this scenario was "aspirational but realistic in terms of potential demand for industrial ... " and based on an assumption that Northland would benefit from Auckland's growth.
"We expect that this 'Auckland effect' could lift economic growth in Northland to a level a little above the rest of New Zealand, but not as high as Auckland itself," it read.
Vacant
A vacant 300ha site at Marsden Point - set aside by Northland Harbour Board in the 1960s for "strategic acquisition" - also got a mention.
Now a dairy farm run by Marsden Maritime Holdings, the land is still earmarked for future investment, "based on the assumption that some major facility or industry becomes commercially unviable in Auckland, due to high land prices, and relocates to Whangarei District".
"One possible facility that could fall into this category is the vehicle import terminal in Auckland. This facility will come under increasing pressure in the future due to plans to redevelop the Fort St area, to obtain community and commercial access to the waterfront in this area," the report states.
"It could therefore be argued that the continuing existence of 300 hectares of vacant land in this area does not indicate an over-investment in infrastructure for industrial land, but instead keeps this land available to attract significant activity to Northland in the future."
It also suggests that the WDC would need to develop an additional 300ha of industrial land by 2031 if the MMH land, earmarked for future development such as a vehicle import terminal, remains as a dairy farm.
Tony Horton, the WDC's senior strategic planner, said there was no shortage of land in the district. "It's more a question of whether the vacant industrial zoned land that we've got is in the right location."
Business as usual
The second estimate, a business as usual (BAU) study, showed an employment increase of 2933 roles.
It considered the rate of employment growth in key industries in the past 10 years, and compared the growth to the same industries nationally, assuming growth would continue to 2031.
Under the BAU, occupied industrial land in Northland could increase by 33 per cent, from 1756.4ha in 2013 to 2318.5ha in 2031, bringing job totals to 12,021, up from 9088. The major industrial increases could come from light industry (+1429 jobs) and industrial services (+788).
There are seven key industrial Census Area Units (CAUs) in Northland - Dargaville, Kaitaia East, Kerikeri, Whangarei Central, Marsden Ruakaka, Springs Flat and Port Limeburners.
While the report said the WDC had enough unoccupied industrial land to accommodate expected growth, with about 760ha of vacant land (including the Marsden farm), it could not be sure the land had the necessary attributes, such as access to transport or allotment size, "to be attractive and viable for industrial activity".
To change the zoning, the WDC would need to go through the statutory RMA process allowing the public and landowners to be part of the discussion.
The report suggested the WDC must gather conclusive evidence to track growth in the district, including survey companies on existing industrial land about their plans to expand.
Horton said a survey of local companies would start next year.
Room to grow
The report warned that the lack of proactive planning on land could hinder growth and affect land prices.
"From the information received, it appears that the level of development contributions is significantly less of a material concern when compared to the effect that permissive zoning can have on land prices," it said.
Permissive zoning meant the zone had few mechanisms to control land use.
"So industrial zoning which does not adequately control non-industrial land uses threatens the viability of the land," Horton explained.
"For example, new residential uses on relatively cheap industrial land puts pressures on existing industrial activities to minimise noise and odour, therefore making the operation [of] those industries more costly and difficult.
"In the worst case, this can make industrial uses unable to operate."
Another impact was that proliferation of non-industrial uses raises the value of the land as it becomes more attractive to higher value uses such as retail or housing, he said.
Horton said rezoning land was achieved through a plan change, which could be pursued by a private group or developer who pays the cost, or through a council plan change where council paid the costs.
"Rezoning is generally only pursued when the current zoning is not appropriate for the intended use and there is strong justification for the change."
From here, the WDC will share the report's findings with colleagues in Kaipara and Far North District Councils and use the information to inform its 2016 review of business zones in the District Plan.
UNISA is now working on a another report which looks in detail at the labour market and skill that industry requires.
