European pointers on water quality

New Zealand’s freshwater bathing quality is described in terms of whether it’s ’wadeable’ or ‘swimmable’, but do people understand what that means?

Taranaki freshwater swimming spot.

Freshwater bathing in Taranaki ... differences between NZ and European standards for freshwater bathing quality have been analysed in a paper presented to the Council's Policy and Planning Committee.

Comparisons against European standards show that Kiwi tests are more stringent. Sites that are classified ‘unacceptable for bathing’ here could potentially be classifiable as ‘excellent for bathing’ in Europe.

Under criteria set out in the Government’s latest National Policy Statement for Freshwater Management, 41% of Taranaki’s monitored freshwater bathing sites would have to be classified as ‘unacceptable’, mainly because of the short-term run-off contamination that typically happens after high rainfall.

That ‘unacceptable’ rate would drop to 12% if we applied the European standards instead, in part because they take a different view of how to interpret monitoring results but mostly because New Zealand’s criteria are out of alignment with those applied throughout Europe. The differences were analysed in a
paper presented to the Council’s Policy and Planning Committee by the Council’s Director-Environment Quality, Gary Bedford.

“When you consider the way we look at water quality versus the way Europeans look at water quality, some interesting points emerge,” he says.

“The New Zealand standards insist that monitored sites must stay within the contamination guidelines at least 95% of the time. Of the 17 freshwater bathing sites we monitor in Taranaki, five routinely meet the guidelines 92% to 95% of the time. So they’re not acceptable. In Europe, they’d be more than acceptable.”

Mr Bedford says that more importantly, the Europeans also apply different criteria to the levels of bacteria deemed to make freshwater safe or unsafe for swimming.

A level that is ‘unacceptable’ in New Zealand is at the top end of the ‘good’ category across Europe.

“A lot of the current public conversation around freshwater management is focused on the notion that all rivers should be swimmable,” says Mr Bedford. “There needs to be clarity and precision over how you set meaningful and defensible standards to achieve ‘swimmability’, and how you apply them.

“If you look at how the Europeans have approached it, you can appreciate that it’s a complex issue that deserves more than sloganeering.”

More gains in waterways

Monitoring of the health of the region’s waterways continues to produce encouraging results.

River monitoring.

Monitoring of the region's waterways has produced some of the best results ever.

Analysis of the Council’s monitoring for the 2014/2015 year includes some of the best results ever for both ecological health and measures of the physical and chemical pressures on rivers and streams.

Ecological health is assessed by studying the types of tiny insects and other macroinvertebrate species found at monitored sites and is the prime measure of waterway quality. The Council monitors 57 sites and uses records going back more than 20 years.

Twenty-two sites are showing a positive and very significant improvement, up from 15 three years ago, and another seven are showing significant improvement. Strong improvements were noted at Kaupokonui Stream upstream of Kapuni, Mangaehu River at Raupuha Rd, Punehu River at SH45, Kapoaiaia Stream at Wiremu Rd and Wataroa Rd, Mangawhero Stream upstream of Waingongoro River, Kaupokonui Stream upstream of Kaponga and Mangati Stream, Bell Block.

Meanwhile, physical and chemical measures are showing marked improvements at 10 of the 13 sites monitored. These measures include nutrient and bacteriological levels, aesthetic water quality and biological oxygen demand.

The results of this monitoring, as well as that of freshwater recreational bathing sites over the 2015/2016 summer, will be presented in a ‘waterways report card’ to the region later this year.

RECOUNT — Taranaki Regional Council's quarterly newsletter
Issue 101, June 2016