Improving the "swimmability" of New Zealand's rivers by just 7 per cent could cost more than $200m each year, a new analysis has found. Photo / File
Improving the "swimmability" of New Zealand's rivers by just 7 per cent could cost more than $200m each year, a new analysis has found. Photo / File
Improving the "swimmability" of New Zealand's rivers by just 7 per cent could cost more than $200m each year, a new analysis has found.
The report published by the Ministry for the Environment looked at work underway in different regions to meet water quality standards set by the previous government.
The main goals were to improve water quality across all areas, and make 90 per cent of rivers and lakes suitable for swimming by 2040, and 80 per cent by 2030.
A "swimmable" waterway was considered one that fell inside the best three of five baseline categories.
It meant that the average risk of infection from E Coli was as low as one to three per cent, and that the health risk from cyanobacteria in lakes ranged from moderate to no different from natural conditions.
Going by that measure, 71.2 per cent of the country's lakes and rivers were currently "swimmable", while 68.6 per cent of rivers only were deemed safe for a swim.
Auckland, Northland, Waikato, Taranaki and Manawatu-Whanganui had the worst overall rates of swimmable rivers, at 23 per cent, 24 per cent, 37 per cent, 39 per cent and 43 per cent respectively.
Marlborough, Nelson, Tasman, the West Coast and the Bay of Plenty all had the best rates, ranging between 95 per cent and 100 per cent.
The new analysis suggested that if committed work around the country was completed - and that included proposals for stock exclusion - New Zealand's swimmability would rise to 76 per cent for rivers and 78.1 per cent overall.
But it would come at a big cost.
An economics assessment put the annual cost involved at $217m, $135m of which would be borne by the rural sector.
The sheep and beef sector would meet 59 per cent of that, with dairy, dairy grazing, deer and lifestyle farms contributing 16 per cent, 3 per cent, 3 per cent and 19 per cent respectively.
Source / Ministry for the Environment
The higher cost for sheep and beef farming was due to the current low level - and price - of stream fencing on that type of land.
Other factors included the need to invest in water reticulation following stream fencing to provide livestock access to water, and the generally large area used.
Source / Ministry for the Environment
The cost would be even higher if sheep were required to be excluded from streams as well.
By region, the biggest contribution to that cost - about 40 per cent - would come from Auckland, where most of the population lived, and where large commitments had been made to improve wastewater.
Canterbury would shoulder around 15 per cent of that cost, while Waikato would contribute 9 per cent.
