The presence of pumps in a flood defence scheme will benefit those involved and the overall success of the scheme.
Many consider flood defences to be impenetrable walls blocking water from entering homes and properties. However, often only consider what is immediately visible, the flood walls or flood barriers, whilst visually impressive, don’t tell the full story.
When people think of flood defences, they usually picture tall walls or sturdy barriers keeping water out. These are certainly important, but they’re only part of the story. What’s often overlooked is the hidden side of flood protection, and that’s where pumps come in.
The presence of pumps in a flood defence scheme can make the difference between success and failure. They don’t just remove water, they help the entire system work as intended.
A flood wall may look impressive, but no wall is completely watertight. When floodwater builds up on one side, it creates pressure in the ground, known as a hydraulic gradient. That pressure pushes water underneath the wall, where it can rise on the “dry” side as groundwater.
If that groundwater isn’t managed, it will eventually equalise with the floodwater outside, meaning your protected area could still flood, filling up from below… or from rainwater as the surface water network cannot drain away the water falling inside the defence.
The rate of seepage depends on soil type. Sandy soils allow water to pass through faster than clay, but both can allow significant water movement over time.
To counter this, pumps are used to collect and remove the seepage water from the dry side of the wall, typically through sumps or collection chambers. These sumps capture groundwater, and the pumps transfer it safely back to the “wet” side, maintaining a lower water level behind the defences.
Pump capacity is usually based on experience, previous site data, or basic hydraulic calculations. While soil seepage surveys can provide more precision, practical experience often guides the decision-making process.
Even where permanent flood walls aren’t practical, pumps play a vital role in Property Flood Resilience (PFR) measures.
PFR products are most effective in shorter-duration floods and flash flooding. However, during longer events, water can seep through walls, floors, or small openings. Having a pump on hand helps keep that ingress under control.
For smaller, short-term floods, Puddle Pumps are a great, affordable option. They can remove water quickly and efficiently, often down to as little as 1mm, helping to minimise damage. In deeper or more prolonged flood situations, a sump pump may be more suitable.
There are pumps for every situation, from compact puddle pumps you can store in a cupboard to powerful automatic systems that help protect basements day and night, operating without human intervention.
There are also a range of very powerful water pumps available, such as the APP HD-15 Submersible Site Pump - High Flow Rate Water Pump which has a flow rate of up to 830 litres/minute.
Pumps are available as manual or automatic, for example, if a person’s basement regularly flooded, they could install an automatic pump which would turn itself on when the water reached a certain level and then turn itself off once it had reduced the water to a particular level.
Flooding like this typically occurs via groundwater flooding, or other ingress routes in river or surface water flooding. Below you’ll see a photo of a property with a small sump that houses an AMA Drainer 301 Automatic Submersible Water Pump 230v | Manual and Automatic Modes, this handles the day to day ingress of water that can be normal into a cellar, with a much more powerful APP HD-15 pump that will activate should the cellar become inundated with flood water, In a flood event, and additional capacity be required.
Water pumps can also be used in conjunction with temporary or roll out flood barriers, where pumps offer an inexpensive and effective line of defence against flood waters. Temporary barriers don’t require prior installation like flood doors, can be deployed in a matter of minutes and thus freestanding temporary barriers, such as the Water-Gate, will always allow a small amount of water to seep through underneath as they do not have a formal foundation.
For as little as £100, a pump can provide a vital extra layer of protection. It’s one of the simplest, most cost-effective ways to strengthen any flood defence scheme, whether for a home, business, or larger site.
Pumps not only move water away from vulnerable areas; they also support and enhance other defences already in place. From manual puddle pumps to fully automated systems, there’s usually a solution for every property and budget.
While we can’t give site-specific recommendations over the phone, we can help you understand the different options available. Our team has extensive experience with flood defence systems, sump and submersible pumps, and can point you towards the most suitable setup for your needs.
We’ve also put together a range of guides, videos, and how-to guides to help you make the most of your investment and ensure your pump performs when it’s needed most.
Order Online or call our UK Helpdesk on 0115 987 0358.
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