Tuesday, 05 May 2020 10:16

Water quality – not just farming’s problem

Written by  Peter Burke
Water quality: not just an issue for farmers. Water quality: not just an issue for farmers.

A report by the Government is offering further evidence that New Zealand’s freshwater is being impacted not just by farming but equally by urban development, forestry and other human activities.

Our Freshwater 2020, by the Ministry for the Environment (MfE) and the Department of Statistics (DoS), highlights how climate change is set to make the issues faced by our freshwater environments even worse.  

The report’s authors say it builds on the information presented in previous reports but goes deeper on the issues affecting freshwater in NZ. This includes new insights on the health of freshwater ecosystems, heavy metals in urban streams, consented water takes and expected changes due to climate change.

The aim, say MfE and DoS, is to provide the evidence to enable an open and honest conversation about available options and to tell a national story, while recognising that significant regional variations exist. It notes that the data and science presented in the report is up-to-date and the best available, but that there is much more work needed to be done.

It does conclude that most rivers in farming areas are polluted, quoting studies at national, regional, and catchment scales showing that show the concentrations of nitrogen, phosphorus, sediment, and E. coli in rivers all increase as the area of farmland upstream increases.  It says farm animals are a source of freshwater pollutants such as dissolved nitrogen, phosphorus, and pathogens and that fertiliser and animal dung and urine are important sources of phosphorus.

It notes that dairy cattle numbers have increased by 70% in NZ since 1994 and that farming has intensified with higher stock numbers per hectare in many regions.

But the report also notes that most of the rivers in catchments in the urban land-cover class are polluted with nutrients and suspended sediment, and many are polluted with pathogens and heavy metals.  And it points to a problem with aging infrastructure in urban areas, which is leading to pollution.

Farmer reaction

DairyNZ says the report highlights NZ’s environmental challenges and where everyone can play a part. 

Strategy and investment leader for environment, Dr David Burger, says dairy farmers are committed to protecting the environment and taking action on-farm to support that.

“Our dairy sector is on the journey to improve and protect water quality outcomes and our farmers have been working toward this for over a decade. We are continuing to do more every year. The Freshwater 2020 report does draw some key themes together for urban, farming and forestry, and shows us that all land use has an impact on our freshwater,” he says. 

But Burger says the report’s approach compares current water quality with native forest waterway condition and DairyNZ believes it is therefore somewhat misleading.

“We know that all development has an impact on water quality but it is unrealistic to compare this to native forest state. An estimated 95% of total river length in pastoral catchments exceeded one or more guideline values, simply because they are being compared to a very high native forest standard. 

“Interestingly, more than 50% of native waterways also failed to meet this criteria. This sets the benchmark very high for catchments with modified land use,” he says.

Federated Farmers says the data and findings in the report provide powerful backing for the case for greater investment in water storage. 

More like this

Have your say

DairyNZ says it will complete a submission on both the winter grazing and the freshwater farm plan consultations, providing firm feedback to Government.

Choosing the right pump

Choosing the right pump for an effluent system is the key to ensuring a system works well and gives many years of reliable service.

B+LNZ remains unconvinced by low-slope map

The Government’s new proposed low-slope map for stock exclusion is better than the original, however the map still won’t practically work on the ground, says Beef+Lamb New Zealand (B+LNZ).

Protecting water in winter

OPINION: Wet and wild winter weather can place increased pressure on the banks of waterways, increasing the risk of them being eroded. This can harm water quality and disrupt ecosystems that support biodiversity and water quality.

National

Machinery & Products

Effluent injection goes XL

Dutch effluent specialist Vredo is testing 15 and 18-metre wide slurry injection rigs for the upcoming 2022 spreading season.

Choosing the right pump

Choosing the right pump for an effluent system is the key to ensuring a system works well and gives many…

Spreading muck with ease

Palmerston North headquartered Strautmann Hopkins Ltd imports the extensive range of Strautmann Muck Spreaders for farmers and contractors, built by…

» The RNG Weather Report

» Latest Print Issues Online

Milking It

Liquid or powder?

Fonterra, the biggest exporter of milk powder to Sri Lanka, may have a new battle on its hands.

Failed legal action

UK vegan and animal rights groups have failed in a bid to ban an advertising campaign promoting meat and dairy…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter