The LGNZ study authors question the Government’s national nitrogen and phosphorus standards and whether they should be applied on a more targeted basis.
The report is based on modelling done for Waikato Regional Council’s Plan Change 1 (Healthy Rivers) and for Southland’s economic model for freshwater management.
A key concern is national averaging phosphorus and nitrogen levels in waterways is something of a blunt instrument to improve water quality, citing statistical evidence nutrients might explain only part of the variation in water’s ecologic health.
“As regional councils we are being asked to assess whether national uniform bottom lines capture the complexity of the situation and the risk factors faced by New Zealand’s varied freshwater systems,” Waikato Regional Council chief executive and LGNZ regional sector water chairman Vaughan Payne said.
The research points to an apparent lack of correlation between ecosystem health, including fish and invertebrates, and nitrogen and phosphorus levels in Waikato.
The use of the macro-invertebrate community index (MCI) as one of the new indicators in the freshwater package as an indicator of excess nitrogen or phosphorus is therefore challenged, the report said.
“Consequently, the cost-effectiveness of policies targeting nutrients is likely to be questionable.”
Modelling the Waikato catchment based on the nitrogen and phosphorus limits proposed, the report found drystock farming would fall from 43% of land use to 14%, with forestry increasing from 20% to more than 50%. Dairying would fall by 13%.
Overall, the changes in land use required will see total farm profit across the region decline by $7 million a year, with forestry profits offsetting significant amounts of pastoral income declines.
However, when land use transition costs are factored in at a cost of $84m a year, the annual cost of meeting nitrogen and phosphorus levels is estimated at about $100m a year or 11% of the catchment’s total land use profits.
Northland, Bay of Plenty and Hauraki Plains are also likely to suffer the same level of over-spend for smaller environmental gains.
Mandatory farm environment plans also appear to be favoured under the Government’s new freshwater package and many farmers already have them.
But the report notes fast tracking the plans to be done by early next decade brings major pressure on resources and skills required to complete them.
Based on Plan Change 10 in Rotorua the authors estimate seven council staff are required to deliver 300 plans a year.
“Subsidising the cost of plans is unlikely to overcome this critical skilled labour constraint in the short run and there is a risk that financial assistance may inflate the price of plans rather than improve or hasten their delivery.”
The report estimates a first cut figure of a net value-add of plan creation for all farms in Southland by 2030 will actually be a deficit of $17m.
Payne said LGNZ is conscious the submission period that closes on October 17 is tight.
“We are very conscious about total wellbeing, improving environmental outcomes will have economic and community impacts. Our initial work suggests the economic impacts will be significant and these need to be carefully managed.
