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What are Permeable Pavers and do they Reduce Stormwater Runoff?

Updated: Feb 20


Paving is an attractive and practical way to utilise a surface for many things. You can increase the visual appeal, rescue an unused area, create a designated space, or get more out of your land. There is a reason that paving is so popular.

Unfortunately, the rising popularity of paving has meant that there are more hard surfaces, and less garden areas. This can prove troublesome when it comes to stormwater runoff. Instead of it seeping into soft grassy areas, the excess water flows over the hard surface and needs to be collected somewhere to prevent flooding. Managing stormwater using alternatives to pipes is becoming more and more important. Are permeable pavers a solution to this problem?

Let’s look into this now.

What are Permeable Pavers?

Firstly, before you can decide if they are worth the investment, you need to know what permeable pavers actually are.

Permeable paving is made from a range of materials and has a porous design. That means it is designed for fluids to flow through the pavers and to be absorbed back into the ground instead of collecting in puddles on the surface. They are made from a range of materials like stone, asphalt, plastic, or a concrete system with gaps between the pavers.

Why Permeable Paving?

This kind of paving has many benefits to your home or workplace, but also for the environment. They are…

Reducing stormwater runoff: excess water can be damaging to urban areas and can cause large levels of erosion. Instead of needing to rely on ponds or other methods to control stormwater runoff, permeable pavers are designed to return the water back to the earth. This prevents the need for potential water hazards, flooding, and riverbank erosion.

Managing pollutants: runoff and stormwater always contains pollutants. As it flows across a surface, the water picks up particles of oil, petrol, and many other pollutants. When it collects in stormwater reservoirs, these pollutants can cause erosion. But, with permeable paving, the runoff does not have to flow to a reservoir, instead, it flows through the paving. The pollutants are filtered out so that water is the only component that returns to the soil.

Environmentally friendly: this kind of paving can help equip homes and workplaces to deal with excess water in an environmentally friendly way. Rainwater that gathers needs to be drained away somehow and most drainage systems divert water back to sewers, ponds, or rivers that aren’t always equipped to handle the increased flow. Sometimes this can cause damage, overflow and for the riverbanks to collapse. Letting the water soak into the soil in a controlled matter is a far more sustainable solution.

Durable: permeable pavers can be used in a variety of climates. Due to the air pockets within stone pavers, or the earth between other permeable options, these pavers deal better with heat in summer and colder temperatures in winter. They are able to handle a freeze and thaw cycle without damage, allowing the snow to thaw and drain away without concern. They can be used in a variety of places like driveways, BBQ areas, car parks, patios, pool areas, paths, sidewalks, service lanes and for many other functions.

Do They Work?

The key to having your pavers perform the correct function is to ensure they are properly installed by a professional, and that they are well maintained.

Permeable pavers can be installed on most surfaces, but there may be some preparation works needed before they can be laid. They also need to be installed with the correct layering to ensure the water can flow through and drain as it is meant to.

Maintenance is also an important factor in their success. Ensure you sweep away any leaves of debris from the surface or the water will not be able to flow through. Water blast them annually to remove any build up. And always remember to place a covering down before dumping a load of sand or topsoil to prevent clogging happening.

Permeable pavers could be the urban solution to excess stormwater. They allow water to return to the soil without the worry of flooding or overloading drainage systems. But in order for them to work correctly, they need to be installed well and maintained. Their popularity is certainly growing as an environmentally friendly paving option here in New Zealand.

Stormwater Management Areas

In Auckland, many sites are now affected by a Stormwater Management Area Overlay (SMAF), where resource consent is needed for redevelopment and development over certain thresholds. Alternatives to traditional stormwater pipes and reticulation are important in these areas; contact us if you’d like advice on getting resource consent in these overlays.

Disclaimer As with all our blogs, the information detailed here is general in nature and meant as a preliminary guide only. This should not be substituted for your own investigations or use of your own professional’s. Planning Plus is not liable for any errors or omissions.

© Planning Plus Ltd 2024

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