When a property sits beside a stream, heavy rainfall can change everything in a matter of hours. This case study looks at how one homeowner used an affordable submersible pump, the EGO 500 GI, to manage water collecting behind their garden flood wall during a real flood event, and what it tells us about property-level flood planning.
The property and the problem
The property backs onto a small stream that, in very heavy rainfall, can rise high enough to overtop its banks and threaten the rear garden. A previous owner had built a flood wall in the 1990s to keep water away from the house, and during this event it did its main job: it held back the main body of floodwater from the stream.
The difficulty is that no wall is perfect even if it has been designed with suitable foundations, seepage control and drainage. After the stream had been high for several hours, water began to pool on the protected side of the wall. This is common where:
- floodwater sits against a wall for a prolonged period;
- water migrates through the ground beneath or around the defence;
- surface water becomes trapped on the dry side with nowhere to drain;
- there is no permanent sump or pump station to remove what collects.
The wall was still valuable, but the homeowner needed a way to deal with the water building up inside the garden.
Why the EGO 500 GI suited this job
The homeowner reached for an EGO 500 GI submersible pump with a discharge hose, to lift the pooled water from the protected side and move it back over the wall towards the stream.
It is a sensible choice for this kind of emergency or semi-planned response for three reasons. It offers strong value for money, which matters when a pump may sit unused between events. It runs in either automatic or manual mode, so it can switch itself on as water rises, or be taken under direct control during a flood. And it passes solids up to 9mm, so it copes with the muddy, debris-laden water a flood leaves behind rather than clogging like a clean-water pump. With a flow of around 170 litres per minute, it shifts a meaningful volume on a standard domestic supply.
What happened on site
As the level rose behind the wall, the EGO 500 GI was placed into the pooled water and used to pump it back over the defence. This steadily reduced the depth on the inside of the wall and helped keep the floodwater from reaching the property. The homeowner's photos show the pump working in the standing muddy water, with the discharge hose routed to carry water away from the affected area.
The engineering view
In an ideal world, a flood wall in this position would have been built with a deeper foundation or a seepage cut-off to reduce groundwater migration beneath it. Even then, surface water can still collect on the protected side during intense rainfall, especially where the wall also stops that water draining away naturally.
For a permanent, robust arrangement, the preferred solution is usually a packaged pump station: a sump chamber, automatic pumps, non-return valves and a designed discharge route, so collected water is removed without anyone present. If you are weighing up a permanent system, our Engineering Review service can help, and for a full site assessment and drainage design our sister company offers a drainage review.
For many homeowners, though, a portable pump like the EGO 500 GI is a practical and affordable way to manage water during an event, ready to deploy the moment it is needed.
The outcome
The EGO 500 GI let the homeowner actively manage the water collecting inside the flood wall and reduce the risk of it reaching the house. It is not a substitute for a fully designed flood mitigation system, but as a good-value pump for domestic flood response, it did exactly what was needed.
Importantly, the inside of the house remained dry.
What you can take from this
A pump is an important part of any property-level flood plan. Barriers and walls reduce the route floodwater takes into a site, but water can still collect behind them during prolonged or intense rainfall. Having a reliable pump ready can be the difference between water being managed outside and water reaching the building.
If your garden or yard floods from a stream, surface water or run-off, see our surface water pumps, or the full puddle pumps range.
A note on discharge: when pumping floodwater, make sure it is directed to a sensible, legal discharge point and never pump foul or contaminated water to a watercourse.
