Freshwater quality on the up and up

20 March 2014

Taranaki’s rivers and streams continue to stabilise and improve, with latest environmental monitoring results the best ever in two decades of testing by the Taranaki Regional Council.

Two new Council reports show widespread and encouraging gains in the ecological health of waterways, while nutrient levels in particular are stabilising and being reduced in some cases and fall well within proposed national guidelines.

The Council assesses water quality in two ways – primarily by examining what sort of tiny creatures are living in streams (“ecological health”), and also by analysing water samples to determine the levels of nutrients, bacteria and a host of other parameters (“physicochemical state”).

For both sets of measures, the latest state of the environment monitoring reports, for the 2012/2013 year, have recently been published, covering the results of recent monitoring and analysing medium- and long-term trends.

“In terms of ecological health, we’re seeing many waterways in the best state ever recorded, and a similar picture emerges when we look at physicochemical parameters,” says the Council’s Director-Environment Quality.

“The latest results build on good results seen in recent years and represent another significant step forward for the whole region. What’s particularly encouraging is that we are seeing some good gains in mid to lower catchment areas, where waterways flow through intensively farmed land.”

But Mr Bedford says the reports also indicate there are matters which still need attention.

Highlights of the latest reports include:

Ecological health
• During 2012-13, 20 of the 57 monitored sites reached their highest individual scores for health ever seen in nearly two decades of monitoring, as measured using an internationally recognised ranking system.
• No site reached a record low in 2012-2013.
• Trends at 44 sites (77% of the total) are showing marked signs of improving ecological health. Only eight sites now show signs of deterioration, down from 10 in the previous year and 12 two years ago.
• Looking at long-term trends, 26 sites are showing ‘strong’ or ‘very strong’ improvement – that’s four times as many showing strong improvement even six years ago.
• Not a single site shows ‘strong’ or ‘very strong’ deterioration.

Physicochemical state
• Sites are sampled monthly and analysed for up to 22 parameters including organic contamination, bacteriological quality, appearance, nutrient levels, conductivity, pH and temperature.
• Measurements of organic contamination, bacteria and aesthetic quality show stability or improvement.
• For the first time in annual monitoring programmes, no site showed an increase in nitrate, ammonia and total nitrogen during 2012-13. Of the 11 sites monitored, six are stable and five are improving in their nitrogen measures. The long-term trend over the past 18 years shows nitrogen levels reducing at 45% of sites and stable at the remainder.
• Phosphate levels are being stabilised and reduced across the region, reversing a previous trend of deterioration. Seven of the 11 monitored sites are stable, three are improving significantly and one (notably, near the Egmont National Park boundary) is deteriorating in one of its phosphate measures.

The full reports can be found on the Taranaki Regional Council website, www.trc.govt.nz. They will also be comprehensively summarised in a Waterways Update to be distributed with community newspapers in the region later in the year.

Links to the full reports
Ecological health (6 MB): http://bit.ly/1nkZ5bC
Physicochemical state (1.7 MB): http://bit.ly/1lru69d

ENDS

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