A tributary of the Wairoa River that flows into Te Tai Tokerau’s (Northland's) Kaipara Harbour, the Wairua is part of the vast Hikurangi wetland. The Wairua was once pristine but is now described by some locals as a polluted ditch.
The Wairua is a prime example of how harmful allowing stock into waterways can be.
Locals have noticed dead cows in the water, banks eroded by cow hooves, pools of cow urine in the hoofprints on the banks, and a declining tuna (eel) population. High levels of nitrogen run-off from dairy farms have had a big impact on the river.
Not only does nitrogen and E. coli from cow waste make the Wairua risky to swim in without contracting a waterborne disease, fish suffer too, as excessive weed growth gobbles up the oxygen in the water, and river-choking sediments travel all the way down to the Harbour.
River champion and kaitiaki Millan Ruka from Ngūrioroi has shown several Green MPs the ways in which both beef and dairy cattle are impacting the water quality and the banks of the river. Great efforts are being made to restore the tuna population, but Millan reports that the detailed monitoring information on water quality and stock in water that he regularly provides to the Northland Regional Council is not usually acted upon.