Permeable Concrete for Smarter Drainage on Larger Properties
How permeable concrete can help us rethink pathways, landscaping and water around larger properties. After years of working with concrete around people’s homes, I’ve noticed something interesting about drainage.
We sometimes talk about water as though it has a mind of its own.
Where did that water come from?
Why is it going over there?
Why does this area keep flooding?
The reality is usually much less mysterious.
Water will take the easiest path available to it. If we don’t give it one, it will eventually find one for itself.
If your entire backyard falls toward your house, that’s where the water wants to go. If raised garden beds create a barrier across its natural path, you’ve potentially created a dam. If hundreds of square metres of hard surfaces suddenly collect rainfall that previously landed on soil and grass, that water now has to go somewhere else.
For me, good drainage design starts there.
Not with:
How many drains can we install?
But:
Where does the water naturally want to go?
More Drainage Isn’t Always the Answer
A common response to a water problem is to add another drain. Sometimes that’s exactly what is needed.
But there is a limit.
Many residential properties ultimately rely on relatively small stormwater infrastructure to get water away from the home. During normal rainfall, that system may work perfectly well.
During a serious downpour, the equation changes.
Once the downstream system reaches capacity, adding another drain at the surface doesn’t magically create more capacity at the other end.
Older properties introduce another consideration. A stormwater system that has been underground for ten, twenty or thirty years may not perform exactly as it did when it was installed. Tree roots, sediment, damage or blockages can all affect its performance.
That’s why I think we need to broaden the conversation.
Instead of only asking how we can collect more water and put it into pipes, perhaps we should also ask:
Where can we avoid creating the runoff in the first place?
That’s where permeable surfaces become interesting.
Concrete That Lets Water Through
Most of us think of concrete as solid and impermeable.
Rain hits it, travels across the surface, finds the lowest point and eventually reaches a drain, garden, lawn or somewhere we didn’t necessarily want it.
Permeable concrete works differently.
Products such as Hydromedia are made with an interconnected void structure that allows water to move through the concrete surface into a specially designed layer beneath it.
Depending on the site and how the system is designed, that water can then infiltrate into suitable ground, be temporarily stored below the pavement, redirected elsewhere or potentially captured for reuse.
That doesn’t make drainage irrelevant.
And it certainly doesn’t mean you can put permeable concrete anywhere and forget about water management.
The soil, sub-base, surrounding levels, expected rainfall, intended use and overall drainage strategy still matter.
But it gives us another tool.
And on the right property, I think it’s a fascinating one.
I Wouldn’t Put It Everywhere
I’m a concrete contractor, and I’ll happily say this:
I don’t think permeable concrete is going to replace conventional residential concrete.
Nor should it.
For a typical suburban driveway, I’d generally still lean toward a well-designed conventional concrete system that gives us the structural performance, finish and aesthetic we’re trying to achieve while deliberately directing water where it needs to go.
Where permeable concrete gets much more interesting to me is on larger properties.
Imagine an acreage home surrounded by established vegetation.
The owners want to create a long walking trail through the property.
They want something you can comfortably walk along after rain. The kids can ride their bikes on it. It doesn’t need constant topping up like loose gravel might. It creates a defined route through the landscape.
But we also don’t necessarily want to introduce a long ribbon of conventional concrete that sheds every drop of rainfall to either side.
That’s where I start getting excited about the possibilities.
A naturally coloured permeable concrete could wind through the landscape almost like a compacted decomposed-granite trail, with planting coming up around its edges.
The path becomes part of the garden rather than something imposed on top of it.
You gain function and accessibility while still thinking about how water moves through the property.
Start With the Landscape
If I were designing a large property from scratch, I wouldn’t use permeable concrete everywhere simply because it exists.
I’d give every surface a job.
The main driveway might be beautifully finished conventional concrete, designed to complement the architecture and direct water safely toward appropriate collection points or landscaped areas.
Then perhaps a permeable pathway disappears around the side of the home.
It might:
- Connect the house to water tanks.
- Continue toward a shed or secondary area.
- Become a nature walk.
- Create a bike path for the kids.
- Or provide a more permanent route through parts of the landscape where we want accessibility without unnecessarily turning everything into conventional hardscape.
Around that, planting does another job.
Lawns do another.
Garden beds do another.
Existing vegetation does another.
Drainage infrastructure still has its job too.
That’s what I think good exterior design should be.
Not one product trying to solve everything.
A collection of elements, each used where it makes sense.
You wouldn’t put a toilet in the kitchen simply because every home needs one.
Outdoor materials deserve the same consideration.
Concrete is brilliant at certain things. Planting can completely transform others. Soft landscaping can absorb, soften and bring life to areas where more hardscape would achieve the opposite.
Permeable concrete simply gives us another option between the two.
“Permeable” Doesn’t Mean Maintenance-Free
There is one important reality homeowners should understand.
The reason permeable concrete works is also the reason it needs to be looked after. Its open structure allows water through.
Over time, fine dirt, sediment and organic material can enter those openings and reduce how quickly the surface drains.
That means where and how we use it matters.
A permeable pathway surrounded by established landscaping is a very different proposition from installing one where muddy runoff constantly washes across the surface.
Periodic cleaning may also be needed to maintain permeability.
So I wouldn’t sell permeable concrete as a miracle product.
I’d treat it like every other material around a home:
Understand what it does well, understand its limitations, and use it where those characteristics solve a genuine problem.
Designing With Water Instead of Against It
I think this is the bigger opportunity.
Whether a homeowner ever uses permeable concrete isn’t really the point.
The more important shift is how we think about water when designing our outdoor spaces.
If you’re building on a large property, don’t wait until the driveway, retaining walls, gardens, pool and pathways are designed before asking where the rain will go.
Look at the property.
Where are the high points?
Where are the low points?
Where does water naturally travel?
What happens during ordinary rainfall?
More importantly, what happens during the kind of downpour where every drain and pipe is already working as hard as it can?
Then design around those realities.
Sometimes the answer will be a drain.
Sometimes it will be changing a level or fall.
Sometimes it will be preserving a soft landscaped area.
And perhaps, in the right location, it will be a surface that allows water to pass through it rather than forcing that water somewhere else.
That’s what interests me about permeable concrete.
Not replacing every driveway.
Not concreting more of our properties.
Quite the opposite.
It’s about becoming more deliberate with the areas we do build.
Because when you’re covering hundreds of square metres of a property with driveways, paths, entertaining areas and other hard surfaces, the question shouldn’t only be:
What colour concrete do I want?
It should also be:
What job does this part of my property need to do?
Get that right, and concrete, landscaping and water don’t have to compete with each other.
They can become part of the same design.
