News and Views

Water report backs ‘tackle the hotspots’ approach

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A new fresh water report sets a robust, independent baseline on water quality indicators as well as pointers on where we should concentrate efforts to gain improvements.

Our Fresh Water 2017, from the Ministry for the Environment, echoes a main conclusion of Chief Science Advisor to the PM, Sir Peter Gluckman – New Zealand’s fresh water challenges vary significantly across the country and stem from actions over many decades.

It’s clear to Federated Farmers that the quality of 80% of our waterways is improving or being maintained, and a catchment by catchment approach, using solutions based on science and hard data, is the best way to tackle those rivers and lakes where there is a problem.

Of the 20% or so waterways that have been getting worse there are range of causes, including farm animals, soil erosion, wildfowl such as ducks and geese, trout and koi carp, factory discharges, urban sewage, and storm water.

“It’s the tried and true 80:20 rule,” Federated Farmers water spokesman Chris Allen said.

“Concentrating efforts where there will be greatest gain is a path borne out by the findings and measures in the Ministry for the Environment’s extensive report.”

There has been something of a fixation on nitrates of late and the report notes nitrogen levels are worsening at more river sites than improving.

However, 99% of total river length was estimated not to have nitrate-nitrogen concentrations high enough to affect the growth of a multitude of sensitive freshwater species.

“This is cause for optimism and underlines that we need to concentrate on hotspots and lengths of river where there are significantly decreasing trends,” Mr Allen said.

“In fact, farmers are doing this.

“Significant investment is happening in nutrient budgeting, riparian fencing, and environmental projects which are having a positive outcome on water quality. But much of this is not reflected in this report due to river and groundwater system lag times.

“For example, a recent project involving more than 600 farmers in the upper Waikato where farmers produced a Farm Management Plan and set of actions is showing a 10% decrease in nitrogen losses and a 17% decrease in phosphorous loses,” Mr Allen said.

“Over a billion dollars has been spent by dairy farmers alone since 2012 on environmental improvements. For example, in Taranaki land owners have voluntarily invested close to $19.5 million on riparian work between 2008 and 2014, according to an independent report. More than 99.5 per cent of dairy farms now have riparian management plans, covering 14,000 km of stream bank.”

Federated Farmers welcomes a focus on fresh water species in the MfE report, which notes that of 39 native fish species, 28 are threatened or at risk of extinction. The number of non-native fish species has increased from 12 in the 1930s to 21 in 2010.

The report pulls no punches: “…pest species pose a major threat to fresh water biodiversity”.

Mr Allen said it’s not just water quality at play. The report states that our native galaxid fishes can persist and thrive in habitats that keep out exotic trout with barriers.

There is scientific data showing that trout have replaced native galaxiid fish, and altered how kōura (freshwater crayfish) and other large invertebrates are distributed.

Algal biomass has been found to be six times higher in some streams with trout compared with neighbouring streams without trout.

So as well as dealing with contaminants, the wider challenges will be about removing barriers to fish migration, reducing sediment, restoring wetlands, improving physical habitat,
and having the explicit conversations about the role of sports fish in our rivers and recreational harvest of whitebait, Mr Allen said.

Macro-invertebrates are another important indicator of the health of waterways and a key finding is that our rivers generally have good macro-invertebrates, “with most river segments in the excellent, good, or fair categories”.

One aspect of the report that Federated Farmers takes issue with is the portrayal of irrigation as consuming 51% of consented water in New Zealand. In fact, a large part of this water is used for hydro electricity generation and the true percentage for irrigation is about 21%.

“In summing up, we need to find practical local solutions that are cost effective and are applied at a rate that people can afford,” Mr Allen said.

“This principle should apply to improvements to urban sewage, stormwater systems, farming systems, and pest fish control.

“Whether we are talking about impacts from towns and townships, or farming, forestry, or fishing, or pest animals destroying native wild life in the bush and rivers, the point is we are all in this together and achieving sustainable results both environmentally and economically will only be achieved with all members of the community, including farmers, working towards achieving outcomes catchment by catchment. “

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