As Cantabrians' thoughts turn to summers spent cooling off in local rivers and lakes, Environment Canterbury has started its annual programme of water testing at popular swimming and boating spots.

The testing at 36 sites from the Waitaki catchment to the Ashburton River began mid November and will continue until mid March. Sites include Caroline Bay, the Waitaki and Mackenzie Basin lakes, Lake Opuha, Otaio Gorge, the Ashburton River/Hakatere, Lake Hood and lakes Camp and Clearwater.

Timaru-based Environment Canterbury water quality analyst Graeme Clarke says fresh water will be tested for E. coli which is found in faecal material and can indicate the presence of sickness-causing bacteria. A slightly different test is used to determine the faecal count in sea water.

"Our sites are chosen in consultation with district councils based on local knowledge about the most popular swimming and recreational spots at beaches, rivers and lakes."

Environment Canterbury water portfolio joint chair Cr Angus McKay encourages people to look up their local swimming sites online before heading off to the river or beach. "We know that many sites have very good or good water quality most of the time, but the weekly testing provides valuable extra information," he says.

This year, following new Ministry for the Environment guidelines, there will be additional monitoring for the presence of the toxic cyanobacteria, Phormidium*, which can form algal blooms and produce toxins dangerous to stock and dogs.

Mr Clarke encourages dog owners to keep a visual check on rivers themselves. "If they see any large mats of black algal growth, especially near river edges, they should keep their dogs away and report it to the regional council."

Environment Canterbury employs a university student to carry out the summer testing programme. For the third year running South Canterbury's water sampler is Sara Fraser who comes from Timaru.

"It's an advantage that she is already so familiar with the region's waterways and people may well see her out and about doing her job over summer."

Test results for water quality will be available on ECan's website www.ecan.govt.nz/swimming .

"It's a very easy site to use - just click on the site you are interested in and you'll be able to see not only its overall grade of whether it's safe for swimming but details of the weekly test results," Graeme Clarke says.

At present the indications are that the region's popular swimming spots will be in good condition for the start of summer after a wet spring had ensured regular water flows, he says.

"The water quality in Caroline Bay is looking really good too and that's matched by the work done to upgrade the bay by Timaru District Council."