Environment Canterbury has begun weekly water quality monitoring at 54 freshwater (rivers and lakes) and 46 coastal popular swimming spots from Kaikoura to the Waitaki catchment. The results are updated weekly on the Environment Canterbury website (www.ecan.govt.nz/swimming).

As in previous summers, staff, community volunteers and two university students - one in Christchurch and one in Timaru - take the water samples each week. In Christchurch there are 24 volunteers - 11 taking samples around the Avon-Heathcote Estuary/Ihutai and city beaches, eight volunteers for Lyttelton Harbour beaches and five people covering Akaroa Harbour. One Akaroa sampler covers three separate sites. These sites around the two harbours and estuary begin to be sampled the week of December 7.

"It's great to see the community taking such an active role in monitoring swimming water quality," says Environment Canterbury water portfolio joint chair Cr Eugenie Sage. "People often feel a strong connection to their local beaches and this is a good example of the council and our community sharing this responsibility and increasing understanding of the causes of water pollution at the same time."

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

The best places for water quality region-wide, showing as blue spots on the Environment Canterbury swimming water quality maps are Gore Bay, Motunau Beach, Leithfield Beach, Woodend Beach, Waikuku Beach, Spencerville Beach, Taylors Mistake, Pigeon Bay, Lake Benmore at Ohau C, Lake Ruataniwha camping ground and Lake Opuha at the dam boat ramp. Many other sites are graded as good for swimming with a green spot on the map.

However, even good swimming sites should be avoided immediately after heavy rainfall, which can wash contaminants off roadways and gutters into the river or sea and temporarily affect the water quality.