New Zealand’s Sustainable Water Programme of Action - Water and Agriculture: Sustainability, Markets and Policies - page 324

Over the last 15 years, New Zealand has made significant progress in reducing direct
(point source) discharges of human and agricultural sewage and industrial waste into
waterways. These discharges were easy to identify and address (relative to the difficulty
of managing diffuse discharges), leading to significant and almost immediate
improvements in water quality in many areas. To some degree, however, direct
discharges have been reduced by converting them to diffuse discharges, for example, land
disposal of urban waste and dairy shed waste. With the reduction in direct discharges,
there is evidence that diffuse sources of contaminants from intensive agricultural land
use 8 are now key contributors to rural water quality problems, particularly in lowland
rivers.
Intensive agricultural activities put pressure on water bodies to cope with additional
nutrients, micro-organisms and sediment. Agricultural land use covers over half of New
Zealand, with agriculture being the main base of economic activity in most regions and
provincial cities. Agriculture contributes approximately half of New Zealand's export
earnings and will remain a major contributor to New Zealand's economic growth and, as
a consequence, ongoing pressure to intensify is likely (Ministry for the Environment
2004b). 9
Higher economic returns from farming are possible through either intensifying or
diversifying land use activities. In the case of pastoral farming this could mean
increasing pasture growth (e.g., by adding more fertiliser) and bringing more feed onto
the property (e.g., silage) to enable higher stocking rates. In some cases this could change
the type of farming from a less intensive activity such as sheep and cattle farming to a
more intensive one such as dairy farming. In some regions, for example Canterbury and
Southland, there has been a trend of conversion from sheep farming to more intensive
land uses, particularly dairy farming. Dairy cattle numbers have increased nationally
from about 3.2 million in 1994 to over five million today. In the same period sheep
numbers dropped from 50 million to less than 40 million. The intensification of dairy
farming has occurred through increasing herd sizes, increasing intensity of farming, and
the expansion of dairy farming into new areas. This has been accompanied by an
increased demand for irrigation in often dry parts of the country and by the increased use
of fertilisers (Ministry for the Environment 2005b).
The WPoA is concerned with addressing the management of diffuse discharges
especially where this is an unintended consequence of land use, such as intensive
farming. Currently there are few tools for managing diffuse discharges. The WPoA will
explore how the RMA can manage diffuse discharges, look at research including the use
of computer modelling to assess the potential impact and sources, and whether water or
nutrient trading regimes can be applied.
In most other regions local government has focused mainly on non-regulatory means
for managing diffuse discharges, with an emphasis on encouraging better practice by
enhancing landowner awareness of impacts of land use on water quality. Gains in on-
8. E.g., nitrogen or phosphorus from fertilisers, nitrogen/ammonia from animal urine or silage,

micro-organisms from animal faeces such as campylobacter, and sediment from stock pugging.

9. Economically, the total value of agricultural exports in 2003 was $14.4 billion (equal to 51% of

total mercantile exports) and the sector employs 9.6% of New Zealand's total workforce.