Water-wise design is less about watering less and more about not fighting your own garden every summer. The usual pattern in an unplanned garden is a few genuinely thirsty plants scattered among a majority that would be perfectly happy on far less, which forces a choice between overwatering the drought-tolerant plants or underwatering the thirsty ones every time the tap goes on. Grouping plants by how much water they actually need, sometimes called hydro-zoning, fixes that at the design stage rather than trying to manage it with a hose every evening.
The practical version of this is simple: put your genuinely thirsty plants together in one zone, close to the tap or a hose reel, and keep your drought-tolerant plants in a separate zone further out that gets watered rarely if at all. Once they're separated like this, each zone can be watered on its own appropriate schedule instead of one compromise schedule trying to serve everything in the bed.
New Zealand's native flora gives genuinely drought-tolerant options to build that low-water zone around, not just succulents. Mānuka is rated low-water in this site's own plant data and copes with genuine drought once established, alongside frost and coastal exposure. Hebe is the same: low-water, full-sun, and one of the easiest natives to place in a dry, exposed spot. Lavender, while not a native, sits in the same low-water bracket and pairs naturally with both on sun, soil and water terms. Ornamental salvia belongs in the same group too: full sun, genuinely drought-tolerant once established, and useful for extending flower colour through a dry stretch when a lot of other things are hanging on by a thread.
Not every plant worth having is quite that tough, and that's fine, provided it goes in its own zone rather than mixed through the low-water planting. Harakeke and agapanthus are both rated moderate-water in this site's data: more resilient than a typical thirsty bedding annual, but not in the same bracket as mānuka or hebe, so they suit a transition zone between the genuinely low-water planting and anything that needs regular watering.
Soil work does real, compounding work here too, and this site already covers both pieces in depth: building organic matter into the soil improves how much water it holds between waterings (see this site's guide to understanding your soil type), and a proper mulch layer slows evaporation from the surface on top of that (see the mulching basics guide). Neither replaces smart plant selection, but stacked on top of it, they stretch the gap between waterings further still.
A few habits round out a genuinely water-wise approach. Watering deeply but infrequently, covered in more detail in this site's watering guide, builds deeper root systems that cope with dry spells far better than the shallow roots frequent light watering encourages. Grouping container plants together so they shade each other cuts how fast pots dry out, since a pot loses moisture through its sides as well as its surface. And lawn is usually the first thing to show drought stress and the biggest single water user in an average garden, so shrinking the lawn area in favour of a genuinely low-water planted bed is one of the highest-impact single changes available.
Watering deeply but infrequently, covered in more detail in this site's watering guide, builds deeper root systems that cope with dry spells far better than the shallow roots frequent light watering encourages.
None of this is simply a response to the odd bad heatwave, which this site covers separately as its own acute problem. It's a standing design choice that a lot of New Zealand gardeners and landscapers are already making as summers trend hotter and drier on average, and the payoff compounds every year a garden goes on being planted this way rather than against it.