Public Health Services have issued a heads up to Wairarapa swimmers to check the health status of rivers and beaches before taking a dip.
A Ruamahanga River swimming spot at Kokotau Road, east of Greytown, was last week marked as unsafe and another spot on the same river at Morison's Bush
carried a caution over water quality.
Health Protection officer Peter Wood said a traffic light code available at regional council websites is used to indicate health risks associated with any given waterway in the region.
"The red status means swimming could pose a health risk and contact recreation should be avoided. Amber status indicates the area should be satisfactory for swimming, and green status should be safe for swimming."
People in the Wairarapa District Health Board area can check the status of their favourite swimming sites on the Greater Wellington Regional Council website at www.gw.govt.nz.
The council, together with district authorities, monitors water quality at selected marine and freshwater bathing sites across Wairarapa.
Monitoring results are updated weekly and displayed at the regional council website during the summer bathing season from November 1 to March 31.
As there is a delay between the sampling and reporting of the results, the Public Health Unit recommends swimmers realise it is safest to wait three days after rain before swimming at river swimming spots.
Mr Wood said swimmers and their pets should steer clear of stretches of waterway that are slimy and unusually earthy or musty smelling and that may contain black or dark brown algal mats attached to rocks or floating in the water along river edges.
"If the water looks clean and clear, and it is a sunny day, it should be OK to swim," he said.
Possible symptoms of illness from swimming in contaminated water are skin infections, diarrhoea, and cold or flu-like symptoms. The risk is lower for activities, like boating, which do not involve immersion.
There were no health risk spots reported in Wairarapa on Christmas Eve.