Pumps for Cellar Flooding

Most cellar and basement flooding falls into one of four causes.

Groundwater flooding. When the ground becomes saturated during prolonged or heavy rainfall, the water table can rise above the level of the cellar floor. If the cellar is not tanked or sealed, water enters through cracks, mortar joints, service entry points, or simply through the natural porosity of the brickwork. Groundwater levels also shift over time depending on local extraction from aquifers. In England and Wales, groundwater provides around 33% of the public water supply, managed by the Environment Agency.

Surface water flooding. Overwhelmed external drainage pushes rainwater down walls and into cellars. This is particularly common where downpipes lack formal drainage connections, or where ground levels slope toward the property and pool around the foundations.

River flooding. Intense rainfall causes rivers to overflow their banks. Properties near watercourses are at heightened risk, and river flooding almost always raises local groundwater at the same time.

Water leaks. Burst or leaking clean water pipes can flood a cellar without warning. If the cause is unclear, a water sample can be tested against tap water to confirm whether mains supply is the source.

Other contributors include overflowing gutters directing water down exterior walls, sloped landscaping, and sewer backflow.

Choosing the Right Pump for Your Cellar

The best pump for your cellar depends on how often it floods and how the space is used.

For occasional or one-off flooding, a puddle pump is the simplest and most cost-effective option. It sits directly on the floor with no installation required, and is used manually when needed. The Tsurumi LSC1.4S Puddle Pump can pump down to as low as 1mm, making it ideal for clearing the last of the water. The Stream SPP2-4 Submersible Puddle Pump is also a strong value option for emergency use.

For regular flooding, an automatic submersible pump installed inside a sump is the right approach. The pump activates when water reaches a set level and switches off once drained, giving you a passive system that protects the cellar without intervention. The AMA Drainer 301 is the most popular choice in this scenario, helped by its narrow arm float switch which suits tight sumps. Our Sump Pumps and Packaged Stations range covers complete kits including the FPS Iguazu Sump 635.

For full cellar conversion or waterproofing, pumps work alongside a Type C cavity drainage membrane system. We recommend speaking with a basement waterproofing specialist before undertaking this kind of work, as the pump is one part of a wider system.

For severe flood risk, some properties benefit from a layered setup. A smaller automatic pump handles day-to-day groundwater, with a larger high-capacity pump such as the APP HD-15 ready to activate when river flooding occurs and the primary pump becomes overwhelmed. This is common on riverside properties.

A quick note on safety: petrol and diesel engine driven pumps must never be used inside a cellar or basement due to exhaust fumes. Only electric pumps are suitable for indoor use.

Manual or Automatic?

Manual pumps are turned on and off by the operator. They are cheaper, simpler, and well suited to occasional use.

Automatic pumps are left in position and activate themselves when water rises to a trigger level, then switch off once the level drops. They are essential for properties that flood regularly or where the cellar is not regularly visited. The EGO500 Water Pump offers both modes in one unit, reaching as low as 10mm in manual mode.

For more detail on switch types, see our guide on automatic water pumps and the different switches available.

Benefits of a Permanent Cellar Drainage Pump

A properly installed pump prevents costly water damage, protects stored equipment and stock, and keeps the cellar usable. For pubs, restaurants, and commercial properties where the cellar is operationally critical, a reliable pump is not optional. For homes, it protects boilers, electrics, and storage, and supports any basement conversion or habitable use of the space.