The southern end of Paihia Beach has failed the latest water quality tests, though heavy rain in preceding days may have affected the results. Photo / Peter de Graaf
One of Northland's busiest beaches has been deemed unsuitable for swimming in the latest water test results published by Land Air Water Aotearoa - just as tourists flock to the region.
The southern end of Paihia Beach, opposite Seaview Rd, was one of four swimming spots around the region tofail the latest round of water-quality tests, although water from two other locations in Paihia, at Waitangi Bridge and Te Haumi, was in the clear.
The tests look for faecal bacteria, generally a sign of sewage contamination or run-off from farms and septic tanks, and toxic algae, which can thrive when the water temperature rises.
Previous tests at Paihia had found the water suitable for swimming so the results, based on tests carried out on December 16, may have been influenced by heavy rain in preceding days flushing contamination from the land into the bay.
The other Northland swimming spots deemed unsuitable for swimming were Onerahi (at the playground), Waimamaku River in South Hokianga (at Wekaweka Rd), and Waitangi River (above Haruru Falls).
Caution was advised at harbour and freshwater sites where faecal bacteria levels were elevated but not over the safety limit. They were Church Bay in Tutukaka Harbour, Hātea River at Whangārei Falls, Kerikeri River at Stone Store (though further upstream, at Rainbow Falls, the water passed the test), Ruakākā River at the motor camp, and Tirohanga River near Kawakawa.
Those sites are generally safe but infants, the elderly or people with compromised health may be at risk.
Whangārei's Raumanga Stream received a clean bill of health despite passing through Northland's biggest urban area. Other rivers to get a green light included Ahuroa River (at Piroa Falls, Waipū), Waipapa River (Puketi Forest, near Okaihau) and Waipoua River (Waipoua Forest). Lake Taharoa (Kai Iwi lakes, Kaipara) and Lake Waro (Hikurangi) also passed the test.
Kerikeri's most popular freshwater swimming spot, Charlie's Rock on Waipapa River, is not on the testing list.
All Hokianga Harbour sites passed the water-quality test, despite local concerns about ageing sewerage plants.
Also in the clear were popular estuaries at Mangawhai Heads, Matapouri, Ngunguru and Taipa; lower Whangārei Harbour sites such as McLeod Bay and Taurikura; and Tinopai and Pahi on the Kaipara Harbour.
Beaches which are bursting at the seams with Christmas holiday campers, such as Maitai Bay (Karikari Peninsula), Matauri Bay (Whangaroa) and Uretiti (Bream Bay) were also deemed to be suitable for swimming. General swimming advice from Land Air Water Aotearoa (Lawa) includes avoiding swimming for at least two to three days after heavy or prolonged rain, even at sites that usually have good water quality.
If you can't see your toes in calf-deep water, it's best to wait until the water clears before taking a dip, Lawa's swimming guide advises.
Swimmers should also avoid potential sources of contamination such as flocks of birds, stormwater or wastewater outlets, and be alert for hazards such as currents, rips and submerged objects.
Those indulging in the time-honoured summer tradition of doing bombs off bridges should seek local advice on tides, currents and underwater hazards.
Lawa gets its Northland data from the Northland Regional Council. The results are also published on the international Swim Guide website and app, published by Canadian not-for-profit Swim Drink Fish.
Sixty swimming spots around Northland are monitored weekly during summer for water quality. The risks of swimming in contaminated water include gastrointestinal and skin infections.
A survey of Whangārei's Hātea River in September found it was the third dirtiest waterway in the country, although that study focused on rubbish rather than bacterial contamination.