Everything you need to know about water management and porous paving

Water – it’s a precious resource, especially in this hot, dry country – and one we need to manage and preserve carefully. However, this is not always easy. We face frequent water challenges in Australia, due to drought, heat and increasing extreme weather events that impact water availability. Our rainfall is highly variable, both in distribution and volume, and Australia is the driest inhabited continent in the world.

The reality is that we have a declining water supply coupled with a growing demand, and this is obviously going to be a problem in the not-too-distant future. Water is our most precious resource – and one that we all must do our part to preserve.

Which leads us to porous paving.

You might wonder what paving has got to do with water preservation, and usually the answer would be, “nothing”. But porous paving is not your usual type of pavement, and is one way that we can contribute in our own small way to conserving our water and ensuring a more sustainable future. Porous paving is an intelligent and environmentally responsible surface coverage solution, and is increasingly being used by eco-conscious people worldwide.

So, what is porous paving?

It sounds like an oxymoron, doesn’t it? A traditional pavement surface is solid, not porous, and usually causes the loss of precious rainwater, as the hard surface prevents water being absorbed into the ground. Water builds up on the impervious surface, leading to high levels of surface runoff into local waterways. This causes water systems to become overburdened with influxes of excessive water, leading to problems with flooding and erosion. As well, this runoff carries with it all the pollutants that have built up on your pavement during dry weather, including fertilisers, pesticides, heavy metals, oils, hydrocarbons, detergents, rubber etc.). And obviously these toxins will cause damage to natural habitats and wildlife and contaminate water sources.

There’s no getting around it, traditional pavements are not an environmentally friendly choice. Any time you replace a natural environment with hard, impervious surfaces, there are consequences, most of which are damaging to the environment.

Which is where porous paving comes in.

Porous paving does away with all these problems, by allowing rainwater to seep through the pavement and be absorbed into the ground, rather than pooling on the pavement and then running away. This type of permeable pavement is designed to allow water to drain through the surface, thus reducing runoff, increasing ground infiltration and recharging local groundwater tables.

Porous paving is remarkably versatile, and can be used in a wide variety of applications, such as footpaths, courtyards, pedestrian pavements, residential roads and driveways, tree surrounds, parking lots, swimming pool surrounds, streetscapes and water harvesting applications. It will cope very well with low-volume pedestrian and vehicle traffic, but is not suitable for use on high traffic roads, heavy vehicle driveways and highways.

How porous paving helps with water management

We’ve mentioned above how porous paving allows water to soak down through the ground, rather than running off or forming large puddles. This has huge benefits for a good water management strategy. A porous pavement will reduce peak stormwater discharges from paved areas, and significantly reduce flood risk. It can help control local flooding following storms, and prevent accumulation of water in low-lying areas where it’s not wanted. As well, it helps control flooding in waterways by preventing large influxes of water from quickly swelling water levels. Local groundwater tables are also replenished, and stormwater quality is improved.

Porous paving also limits the contamination of groundwater sources, as the water quickly seeps into the ground, rather than being exposed to bacteria, pollutants and debris.

As well, porous paving can be safely installed around tree roots in urban environments. Trees need plenty of water to survive and thrive, particularly in sunny Queensland with its extreme heat and regular droughts. Large areas of hard pavement lead to lower soil moisture content, making it harder for trees to grow and flourish. Porous paving prevents any of that precious rainwater from being wasted, instead directing it right down to where it’s needed. This also helps eliminate soil compaction and encourage healthier root growth at a greater depth, leading to healthier and more robust trees. Porous paving limits the impact of pavement on plant growth and is a far better land management choice.

To make it even better, porous paving looks far more aesthetically pleasing than conventional drainage channels, and can be seamlessly blended into an urban environment. It can even help make cities cooler, as it reduces the need for concrete and stone pavements, which can retain the heat in hot climates.

Porous paving is a big part of water sensitive urban design, and is something that all conscientious people should consider when undertaking any kind of building or landscaping project. It reduces the impervious area of a site, delays peak runoff flows and provides greater water infiltration back into the ground. We all need to be much more aware of how we use and manage water, and porous paving is one of the newer ways to do just that.

Click here to find a range of high quality porous paving materials to meet the specifications of your project, and get in touch with our experts if you’d like any advice on how to incorporate porous paving.