Water  |  23 Nov 2020

The Garden City’s head gardener is urging Christchurch residents to be mindful of their outdoor water use this summer so the city’s water supply network doesn’t come under too much pressure.

Director of the Botanic Gardens Wolfgang Bopp is part of this year’s “Water like you oughta” campaign, which encourages people to think carefully about how and when they water their gardens.

“Sprinklers and garden irrigation systems use the most household water, so we’re asking people to check how long they’re watering for and when they’re watering,” Mr Bopp says.

“Leaving a sprinkler on for too long in the heat of the day or when it’s windy can waste hundreds of litres of water, and many sprinklers aren’t very accurate.

“Most gardens just need a few minutes of water in the cool of the early morning or late evening. Hand-held watering with a hose or watering can is the most accurate, plus it can be very relaxing – and we could all do with a bit more of that this year.”

Mr Bopp says setting up a water timer is the next best solution.

“Some people may have a built-in irrigation system or a sprinkler permanently in place in their garden. Setting these up with a timer on your tap for a few minutes of watering overnight means your plants can be hydrating while you’re sleeping.”

In summertime the household demand for water in Christchurch generally doubles compared with winter, mostly because of people watering their gardens and lawns.

During peak demand in the early evenings, parts of the city may use water faster than the network can pump it and fill the reservoirs, leading to supply issues and reduced pressure, which can also have an impact on firefighting. When that happens, Christchurch City Council has to impose water restrictions to ensure the safety and continuity of the water supply.

Mr Bopp says making small changes to watering habits can add up to a big difference for the city.

“Lawns don’t need much water, if any, and there’s no real reason to be watering roadside berms. Grass is tougher than most people think. If it does turn brown over summer, it‘ll go green again in autumn.”

Mr Bopp says while the Botanic Gardens has its own private well, which is independent from the city’s water supply network, over the past few years it has been expanding its irrigation system to do as much watering at night-time as possible.

“We’ll be doing whatever we can to support the water conservation campaign, including more automatic irrigation in the Gardens. In my own garden at home, I’m going to install a water-saving drip irrigator for my collection of pot-plants. We all need to pitch in and do what we can this summer, because it’s forecast to be very warm and dry.”

Get more tips on how you can save water.