KEY POINTS:
Parents of pupils at Meadowbank School in Auckland are not surprised if they get told off for washing their cars in the driveway.
The pupils know what many people don't: the soapy water is likely to end up flushed down a drain, into a stream and then out to sea.
Instead, the parents should be washing their cars on the grass or at a car wash where the run-off water is stored and released into the sewage system.
Maddy Brown, aged 7, told the Herald she knew contaminated water could "make the fish sick", and 8-year-old Abraham Taucher said he couldn't swim in the ocean if it wasn't clean.
Nicky Elsmore, a former school parent and now the school's natural science co-ordinator, helps the pupils to learn about water issues as part of Meadowbank's environmental studies.
For about five years the school has been monitoring the quality of the water in a small stream that runs through a bush gully on its grounds.
Pupils gather information on water clarity, measure levels of dissolved oxygen, phosphate, nitrogen and pH, and record its temperature.
The data is sent to Wai Care, a water quality monitoring, education and action programme for community groups and schools in the Auckland region, which is supported by local councils.
Mrs Elsmore said that at times pupils had had to ring the pollution hotline to report their findings.
While the water was generally in good shape, at times the school had noticed raised levels of nitrogen, which could have come from sewage contamination before the stormwater pipes were separated from the sewer pipes.
Tomorrow the information gathered by the pupils will be emailed to the United States in support of World Water Monitoring Day.
That has been organised by Robert White, who has two daughters at the school and is director of the water research company AWT New Zealand.
The company, whose work involves water monitoring, belongs to the International Water Association, which promotes the day and encourages citizens to engage in the basic monitoring of their local water bodies.
Mrs Elsmore said the pupils were excited to know the material they collected would have an international connection.
Interacting with wider communities was an important aspect of the school's Green/Gold status, awarded in 2005 by the Enviroschool programme.
Meadowbank is one of just five schools in the country to hold the status, which requires everyone on its campus to be involved in working towards sustainability, ensuring children are able to learn in the environment and that they engage in environmental responsibility.
That has been achieved through the transformation of the gully.
The school once burned its rubbish there but since 2000 the gully has been cleared of weeds, planted with thousands of trees and made into a unique learning resource.
