Should a flooded underground pump room be waterproofed or moved above flood level?

The short answer

Moving the equipment usually gives more protection, because waterproofing deals with one way in, not all of them. Waterproofing the walls and floor from the inside deals with groundwater seeping through the structure. It does not stop runoff pouring down the stairs or through a hatch, or water backing up from an overflow tank. If the room floods in monsoon storms, moving the equipment to ground level or an upper floor deals with the problem at its source.

Protecting a pump room that stays underground

Where moving is not practical, these measures can be combined, and each is decided per site. All electrical work is carried out by a licensed electrician.

• Raising the pumps onto plinths above floor level
• Moving the switchboards out of the pit to a higher, weatherproof position
• Two or three back-up drainage pumps set at different levels, on separate power supplies
• Low-voltage battery pumps that keep working if the 220 V supply fails
• Ventilation or air conditioning to control damp
• Waterproofing from the inside where groundwater seeps in

How we decide with you

We inspect the plant, the room and the surrounding levels, ask how the water came in and look for space above ground. The answer can be both: move what can be moved and protect what stays. The owner decides the scope, with the villa manager or hotel engineer advising on the site's history and timing. In most cases a new room can be built while the old one keeps running, so the pool can often stay in use for much of the work.

What to send us for a first discussion

• Photos or a short video of the pump room, switchboard, pipes and pool
• The property location and the approximate pool size
• How high the water rose, where it came in and what stopped working