Rainwater tanks will supply fiscal and environmental benefits for school


Last week Nayland College was allocated $75,000 by the Ministry of Education for the installation of rain water tanks to irrigate the school’s playing fields.

The tanks will be installed during the July school holidays and installation will take two weeks.

The tanks will be located in the garden next to the car park behind the gymnasium. The water tanks will use rainwater off the gymnasium roof.

This will benefit Poorman Valley stream as water will no longer be drawn from it for the school’s irrigation needs. The tank water will reduce the needs for herbicide use and field maintenance, providing both environmental and fiscal benefit for the school. “I’m really, really stoked that we got our application over the line”, states John Hall, Nayland College’s Business manager.

The back of the gymnasium will be the location for the new rainwater tanks.  — Duncan McKinlay

Ten years ago, the school got a resource consent from the Nelson City Council to draw water out of Poorman Valley Stream to irrigate the playing fields. 

Late last year, the council advised the school that this resource consent would expire in April of 2020 and that it would be highly unlikely that they would issue a new consent.

Even before the council could consider the consent application, the college would have needed to engage a hydrologist and get an environmental impact report. The council also wanted an engineer designed weir (a small-scale dam) put in the stream. It was estimated that this preliminary work would cost $50,000.

In 2017 there was a big flood which took out all the infrastructure in the stream. Currently there is a well that sits beside the horticulture unit. It takes water out of the stream and then pumps it across the fields. Unfortunately, it no longer works because the water level in the stream is now so low there is nothing to pump out.

Poorman Stream’s water level is too low to continue irrigating the playing fields. — Duncan McKinlay

John said the lack of irrigation was hurting the school financially and was making the field unfit for use.

“Because we couldn’t irrigate, all the grass died off, heaps of weeds appeared and the top field became unplayable,” he said. “When finally the rain came, the grass didn’t come back. So then the college was up for re-sowing the field. There was quite a big expenditure there for the college not only in herbicides to maintain the weeds, but also for resowing and fertilising. It was cost prohibitive to draw water from the main school supply.”

John looked into installing rain water tanks across the back of the school. Water could be harvested off the gymnasium roof, filling up a consecutive line of eight 30,000 litre water tanks. The water tanks would connect to the school’s field irrigation system and during the hotter months irrigate the playing fields every second or third day. This option came with an estimated cost of $80,000.

Around this time, the Ministry of Education announced that schools could apply for a sustainability fund for activities that they wish to engage under that criteria. There were 360 applications.

“I was told the college probably wouldn’t be successful, as it was a very expensive project and the initial thoughts were that the money in that contestable fund was for smaller schools for things like solar energy. We submitted the application in late December, then waited,” John recalls.

Last week, John received the news that Nayland’s application was one of 52 successful applications.

John believes that Nayland’s application was successful because of its uniqueness. “The other applications were for solar panels and LED lighting, so (our proposal) it was quite left of field for them. Even though it was quite an expensive project, this got it across the line”.

By Duncan McKinlay