Designing for a cool city is becoming more and more critical in order to address climate change. Heat waves, lack of shading and a stack of concrete and glass make for a hot environment. Our cities are heating up and we need innovative solutions to counter act this.  

One way to cool down our city is with the addition of street trees. But not just your everyday street tree. Well-chosen and efficiently maintained, water-wise street trees give cities so many benefits.  

So, what are the benefits of street trees to our cities?  

Not only do street trees look nice, but they also literally give our cities life. With the addition of lush, healthy street trees, our cities can become greener and cooler. Ultimately, they make our cities more liveable and can fundamentally change in how they look, feel and work.  

From a climate change perspective, street trees also:  

• improve air quality and remove air pollutants 

• provide shade and cooling 

• reduce the effects of urban heat-island  

• store carbon 

• reduce stormwater runoff 

• encourage biodiversity.

What are passively watered trees?

All good trees need water to survive. So, to make sure they stay healthy, a cleverly designed system using passively watered street trees is efficient and effective.  

Passively watered trees, sometimes referred to as passive irrigation, use existing water supplies wisely, such as stormwater runoff, to ensure the trees are well maintained.

Delivering one million trees to urban areas in Sydney and Melbourne 

If you look across our cities, there are some great state government-funded programs like Greening our City that are aiming to deliver one million trees in urban areas. One of the implicit aims of these programs is to do this through passive watering. 

This is a fantastic goal for our cities.

But unfortunately, can you believe that not everyone loves trees? Especially those that are responsible for picking up the leaves, unblocking the drains, or resurfacing footpaths. 

Designing low-maintenance passively watered street trees 

Wave Consulting Australia has done many projects on passively irrigated street trees.  

Our work with local councils primarily in Melbourne and Sydney, focuses on making sure to avoid the potential pitfalls of poor maintenance with cleverly designed passive street tree irrigation. We work through these issues to create functional designs, backed up by data-driven modelling.  

Our designs create low-maintenance options to green up our cities with street trees that will survive long into the future. For example, we approach our designs with the view that they must not require more than annual maintenance, as quarterly maintenance is four times the price! Larger inlets and easy-to-clear litter traps make this possible.