How does the water table affect a bollard installation?

When you’re making the big decision about which bollards are right for your property – whether they’re driveway bollards or security bollards – you may well come across the term water table. Happily, it’s nothing too technical, and fairly easy to come to grips with. However, it can be a crucial factor in your decision. Here we explain more about what exactly a water table is, and how it can affect the choice and installation of your bollards.

What is the water table?

Put simply, a water table marks the transition between dry, aerated ground, and ground that is saturated with water. It can help to think of it as exactly what it sounds like; a tabletop. The unsaturated level just above it has several names, including the ‘capillary fringe’ or ‘zone of aeration’. The level below it, meanwhile, is often simply known as the ‘zone of saturation’. Here, water runs through all the pores and fractures of the ground. However, while these can all be helpful technical terms, you don’t necessarily need to be familiar with the ins and outs of them to successfully get your bollard installed!

The position of the water table can vary significantly between various locations. The roads and tarmac surfaces of heavy urban areas, for example, will prevent water seeping through to the ground, which means they often have much lower water tables than other residential or more rural areas. Proximity to large bodies of water, such as lakes or oceans, can also have an effect.

The water table affect on a bollard installation?

In short, some bollards need a certain amount of room underground to manoeuvre. Telescopic bollards are a good example of this, as they have to move on a semi-regular basis up and down through the ground. A high water table poses several potential issues for this. First of all, it means that the lower parts of the bollard would be submerged in water all day, which would cause it to rust more quickly. Secondly, it means that when the bollard is dropped, water can often splash back up at the operator (you) and if you’re dressed in a suit and going to work, it’s far from ideal!

To avoid this, when we install a telescopic bollard in areas with a high water table, where necessary we’ll hire the tools to dig a little deeper and use loose gravel to create what is, in effect, a small soak-away underneath the bollard. This prevents a pool of water from forming underneath it, which slows down the formation of rust when it’s down and saves you from any morning disasters when dropping it.

It’s important to bear in mind that this isn’t necessary for every telescopic bollard – we assess each installation on a case by case basis, and always advise if this is an action we’ll need to take.

As you can tell, there are a lot of factors to consider when choosing the right bollard or parking posts for your property, and it’s for these reasons that we take care to maintain a wide selection of bollards here at Bollard Security. What’s more, the water table of your property is one of the key factors we take into account when recommending the best bollard for you. You can take a closer look at our post on how to choose the best driveway security bollards if you still need help making a decision. Alternatively, you can give us a call on 01756 636 196, and our experts will be only too happy to advise!