Northland’s ‘swimmable’ freshwater status
Most of Northland’s most popular freshwater swimming spots – and their coastal equivalents – are suitable for swimming all or most of the time over summer, newly-released regional council data shows.
The council’s annual summer testing programme officially ended on Tuesday and saw hundreds of samples taken from 13 popular freshwater and 46 popular coastal sites.
The final week’s test results are pending, but council chairman Bill Shepherd says data from the previous 13 weeks of the programme shows 93.5 percent (158 out of 169 freshwater samples) met national ‘guideline values’, meaning they were considered suitable for swimming. In coastal areas that figure was 99.8% (596 out of 597 samples).
“Last summer 89.4% of freshwater samples (161 of 180) taken over the full 14 week-long programme were compliant and 99.2% (606 out of 611) of coastal samples.”
Councillor Shepherd says ironically the latest council data comes as the Ministry for the Environment today released maps showing some sections of Northland rivers – many of them not normally swimming sites – that have lower quality for swimming.
He says on the face of it, the maps show Northland has some of the ‘least swimmable’ rivers, streams and lakes in New Zealand and indicate the region still has some way to go in terms of its freshwater.
Councillor Shepherd says it’s difficult to respond to the Ministry’s maps without sounding defensive, however, in recent years the council – and Northland communities – have jointly put a huge amount of time and effort into lifting regional water quality.
“This is at the heart of much of our work and we’re working continuously with communities Northland-wide in that regard.”
Councillor Shepherd says Northland rivers and streams are often short, shallow and pass though pastoral areas susceptible to runoff during moderate to heavy rainfall events; all of which can negatively influence water quality in the short-term.
He says leaving aside any reservations the council has about the methodology and historic nature of some data used to determine the Ministry’s tables – which it believes disadvantage Northland – it will be closely studying the Ministry’s findings to see what further improvements can potentially be made.
“Where improvements are possible and practical, we’re obviously very keen to encourage this; subject of course to the legislation central government says we must operate under.”
Cr Shepherd says the Ministry’s focus appears to be on a desire for people to swim anywhere at any time year-round – including winter and heavy rainfall periods, when people are actually unlikely to swim or want to swim.
In contrast, the council believes a much more sensible and scientific risk-based approach is to focus efforts on freshwater sites where and when Northlanders are most likely to actually be swimming; a key driver behind its long-running summer bathing water monitoring programme.
“This programme typically runs from late November to late February and we test for faecal indicator bacteria used to gauge the risks of contracting gastrointestinal and other infections while using the beaches, rivers and lakes for swimming, water sports and other forms of recreation.”
“In terms of ‘swimmability’ council’s focus for many years now has been on the water quality in the places Northlanders – and visitors to the region – do want to swim and when they want to swim in them.” “In that regard, we believe the vast majority of the time our freshwater is most definitely ‘swimmable’.”
Councillor Shepherd says results are regularly posted on the national environmental reporting website LAWA – www.lawa.org.nz and forwarded to the Whangarei, Far North and Kaipara District Councils, the Northland District Health Board (DHB) and other interested parties.
The DHB and relevant district council are informed of any results showing elevated bacterial levels within 24 hours and it is the board and/or the appropriate district council's responsibility to take action. That can include further testing, public warnings not to swim or gather shellfish and putting up permanent warning signs at the worst sites.
"Interestingly, our own 'faecal source tracking' has indicated one of the main sources of E.coli bacteria in some of our rivers is actually birds, rather than stock and/or humans."
Meanwhile, Cr Shepherd says the council's Draft Regional Plan also contains a number of measures designed to improve and protect water quality, with key proposed changes including new stock exclusion rules for rivers, drains, wetlands and lakes.
"At the same time, the council is also tailoring the way freshwater is managed in the Doubtless Bay, Pouto, Waitangi, Whangarei and Mangere catchments to address issues of particular concern to those communities."
He says catchment groups made up of local community, industry and tangata whenua representatives have also already developed draft catchment management plans that address fresh water related issues and contain rules that apply in addition to/instead of those in the Draft Regional Plan.
"These plans also contain a variety of non-regulatory approaches, including more research and actions to improve the state of fresh water."
Councillor Shepherd says the council has also spent hundreds of thousands of dollars subsidising fencing of waterways to improve water quality through its Environment Fund and remains committed to working with communities on water quality issues.