OPINION: Injecting applied science back into the water quality debate

Discussion around the state of water quality in New Zealand is not short of an opinion or two. Yet when it comes to the science, we’re surprisingly quiet.

Given the emotive nature of the conversation, there is an understandable reluctance for scientists to venture into the public arena when it comes to the freshwater debate. Advocacy has its place, but in this ‘post-truth’ world, where is our earnest voice of truth and reason?

The health of our waterways is undisputedly important to the majority of New Zealanders. However, recent commentary paints a picture of a nation that rests on its laurels and drags the chain in maintaining and improving water quality.

Despite stories of widespread and continued degradation of our waterways - and there are certainly cases where this is true - it is by no means all doom and gloom.

In the Horizons Region we see encouraging signs of improvement. Scientists generally report two key measures for water quality: state and trend. State tells us about the current condition of a waterway; trend tells us how things are changing over time. Recent analysis of 10 and 25 year trends highlights significant improvements in nitrogen, phosphorus and bacteria at a number of sites throughout the Manawatū-Whanganui Region. Many of these sites are located in catchments that include intensive farming.

Novel techniques tell us how long it takes for water (and nutrients) to travel from land to water. We now know that water takes on average less than two years to reach streams in the upper Manawatū Catchment, and four to seven years to move through groundwater to the Manawatū River. This suggests that improvements we are making now may be seen relatively soon.

Reducing run-off through stock exclusion and riparian planting not only reduces in-stream nutrients and bacteria, it also provides much-needed habitat for fish and bugs. The benefits of riparian management are well-established; Horizons targets this work to areas where we can achieve the best outcome for each catchment.

Emerging research suggests that the ability for the environment to process nutrients varies widely. Not all catchments are created equal, and in some areas of our Region, the environment appears to play a significant role in attenuating nutrients before they reach groundwater bores or waterways. As our knowledge of the complex relationships between soil, geology, water quality and ecosystems grows, so too does our understanding of the different levers we can pull to improve the health of our waterways.

There is no disputing that many of New Zealand’s waterways are showing signs of pressure. We cannot become complacent. The challenges before us are difficult and complex, however there is much that can be done.

In our Region, initiatives such as the Manawatū River Leaders’ Accord drive change by ensuring urban wastewater treatment plants are performing as they should, and farmers are improving systems and practices to reduce the amount of sediment, nutrients and bacteria making their way into our waterways.

Ensuring everyone has access to the information Horizons collects is key. As communities, we must have open and honest conversations about water quality and natural resource management. Land, Air, Water Aotearoa (LAWA) is New Zealand’s website for environmental information, providing open access to regional council monitoring data, along with information about how this data is collected, analysed and reported. LAWA includes live access to river flow and groundwater levels, the latest air monitoring and water quality results, and information on the suitability of popular spots for swimming and recreation.

Insinuations of public ignorance and apathy made by some in recent years are, in my experience, largely unfounded. The people of our Region come from all walks of life, across a range of sectors, and hail from both rural and urban communities. We are not naive, nor are we complacent.

As Kiwis, we’re renowned for our ingenuity; our adventurous spirit; our willingness to dig deep and find solutions to the toughest of challenges. We have smart people, with new ideas, who are engaged and forward-thinking. Let’s support them.

We are all responsible for the health of our waterways. Now is the time to set the finger pointing aside and engage in open and honest discussions. While striving to address what is not working, let’s also acknowledge what is.
If honesty is to be served, then let’s ensure it is on everybody’s plate.

Abby Matthews is the Science and Innovation Manager for Horizons Regional Council.

  • Otago University Bachelor of Science
  • Post Graduate Diploma in Science
  • Member of the New Zealand Hydrological Society
  • Member of the New Zealand Chapter of International Association of Hydrogeologists
  • Convener of regional sector groundwater forum
  • Over 10 years experience in natural resource science (industry and government roles)
  • Five years at Horizons Regional Council