Friend of Awa Matakana – Traffic light snapshot of water quality

How healthy are the streams and rivers around Matakana? And how could we improve the freshwater so we can confidently take a refreshing summer dip in clean water?

There are two large and picturesque rivers, and lots of swimming holes, in the Matakana catchment, but in many locations the water is regularly contaminated, either with nutrients or dirt or animal waste. Not ideal for a swim.

Every three months, Friends of Awa Matakanakana (FOAM) volunteers test water quality at 11 sites throughout the catchment. They identify what is living in the freshwater, if there are any contaminants, what is changing and in the longer term, what impact mitigation measures such as riparian planting and wetland regeneration are making. Auckland Council is notified if FOAM finds exceptionally high levels of pollution.

E. coli bacteria is present at almost every site, with many frequently exceeding the level deemed safe for swimming. The levels of sediment in the rivers and the element phosphorus, which causes weed and algal blooms, are very high. FOAM is investigating sources of these.

Volunteers assess water clarity and biodiversity, the number of freshwater critters living at each site, and what nutrients are present. Just as Aotearoa has unique native bird life, we have some unique river life, like freshwater limpets that glow in the dark.

Of the sites FOAM monitors, the better ones are near the top of the catchment. The freshwater runs through private land and many of these landowners have fenced waterways to keep stock out of creeks, planted riparian strips, and protected existing native bush. All these measures help everyone in the catchment downstream and they also reduce flooding.

FOAM has developed a simple traffic light report to share its water quality findings with landowners and the community. The aim is to inform and empower people to make choices about the future of freshwater management and protection.

If it isn’t safe to swim in most of the beautiful Awa Matakanakana catchment, what else can people do during the summer months to enjoy the soothing surrounds of freshwater? Kayaking is an ideal way to explore the catchment because it minimises direct contact with potentially contaminated water and it is accessible for paddlers of all abilities. It is reasonably easy to depart from Sandspit, paddle upstream along the Glen Eden or Matakana rivers with a rising tide, and return when the tide turns. A return trip can be paddled in less than two hours.

Kids of all ages can have fun exploring under rocks in stream beds, dragging a net through the water to see what they can catch or wading into the shallows. All are adventurous and free activities that help us learn about nature without even knowing it. Just make sure you wash your hands well afterwards and please return anything caught back to its home. The critters work hard to keep our rivers clean.

LAWA (Land Air Water Aotearoa) has swimming guidelines for rivers and beaches throughout New Zealand, but Matakana rivers are not included.

For regular water quality traffic light updates of the Matakana Glen Eden catchment go to www.awamatakanakana.home.blog.

Note: FOAM’s information is not intended as a guide to safe swimming because presently, the data set is too small.