I have always been a fan of permeable driveways (except in my younger skateboarding days). They allow for absorption of runoff, recharging aquifers, and naturally filters the water before it reaches ocean, lake and river outfalls, improving water quality. It reduces the dangers from flooding and the need for huge storm drains and channels. Additionally, it can help with the ‘heat island’ effect where the heat of the sun is stored in all of the concrete and asphalt of urban areas, thereby trapping the heat and altering the micro-climate of the area.
There are several methods out there from just using a permeable porous concrete type mix if you prefer a solid looking surface, to a brick style where water can run through the cracks, a basic gravel, or just go all the way and create a green live driveway of grass, turf or native plants. The really easy (and somewhat common) way to create a green driveway is to plant an area and provide a solid surface (such as bricks or concrete strips) for the tires only. No matter what style suits you, there is a greener driveway option out there. Professionals are out there who can help you plan and execute your eco friendly driveway, or you can just do it yourself (DIY). Lets start with the variations on what is available in the way of environmentally friendly driveways.
Porous pavement is a permeable pavement surface which contains a reservoir underneath. The reservoir holds the surface runoff, allowing it to slowly infiltrate into the subsoil. This allows the water to receive some natural filtration treatment. Porous pavement can mimic traditional asphalt or concrete but is manufactured without the fine, dense materials and incorporates hollow spaces that allow for water infiltration. This is not the greenest option, but is a great alternative to a traditional concrete or asphalt driveway. Because of many homeowner association rules and aesthetic considerations, this may be the best option for you.
To make it even better, you can make it a green driveway by adding grass or some type of low growing hearty foliage to help with the absorption of runoff and automobile leaks. There is a great tutorial of a DIY green driveway on frankejames.com where the homeowner actually did all the work themselves, and there are commercially available products from sources such as Invisible Structures. Most living driveways incorporate several layers, starting with a compacted sandy surface to maintain grade, followed by a sandy loam filled support structure (commonly a plastic honeycomb grid) to support the root system and maintain the solid surface to drive on.
Having heard experiences from several of our readers, here are some of the more common tips and considerations:
Steep Driveway Slopes
Steep slopes can cause issues if you choose an open-cell driveway with gravel fill. Gravel can come loose and cause unsafe conditions for automotive traction. For hilly driveway applications, using porous pavement, or gapped porous pavers may be a better option.
Driveway Installation Timing
For most climates, late spring or early summer will provide you with the best weather to install new your new driveway, whether professional or DIY. This will avoid excessive rain, snow, or other inclement weather that may interfere with the installation.
If you own or know of companies with green driveways, please leave a comment below for our readers.