PwC Barrier Solution

BACKGROUND

Following two burst water mains incidents that swamped the underground car park and basement area at their London offices, PwC decided it was time to take action to prevent this from happening again.

The basement area flooded to a depth of approximately 800mm, submerging rooms and flowing through the power room ventilation shaft to knock out power to the whole building.

Aquobex was engaged to ensure these critical areas were protected from future events. As PwC is a tenant in the building, the landlord also had a large input into the proposed final decision.

SOLUTION

Aquobex’s initial proposal was for a single FloodBreak barrier to be installed at the top of the service ramp, however, this was rejected by other tenants in the building. Still using FloodBreak as the obvious solution for flash flooding (as it is a passive barrier), recommendations were made to secure each corridor into the PwC areas. These were then rejected by the landlord, as the floor excavation (even at 300mm deep) would have cut into the rebar and was not acceptable. Installing on top of the floor would have reduced the ceiling height to a very low level.

The third solution was to deploy simple flood gates that are manually closed across the corridors (and flood barriers across the doors) upon receiving notice of a flood. To improve the warning times, alarms were installed at strategic locations around the car park and connected directly to the security guard’s office.

The flood gates were lift-hinge flood gates from Flood Control International and the door barriers were Floodguards, supplied and fitted by Aquobex and including storage facilities nearby. A new floodproof wall also had to be installed by Aquobex’s contractors for one of the entrances.

RESULT

A series of flood gates, slot-in barriers and Floodguards have been installed to protect all the vulnerable corridors and critical infrastructure in eth basement, including the post room.

As these are manual barriers the final part of the project will be to deliver a Flood Emergency Response Plan (FERP) to the customer, so the on-site team is always briefed and aware of their actions when the next flood event occurs.

The FERP is an important part of any manually deployed flood protection system as it highlights the teams actions, the order of closing the gates and the safety instructions for doing so whilst maintain the security and well being of the staff.