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.
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.
Similar versions of the VSL that fit horizontally under air intakes for subways and the metro are being installed in New York but, when this VSL is installed later this year at PwC, it will be the first of its kind anywhere in the world.
David Chambers, PwC, is very excited to be at the leading edge of flood protection solutions and is eagerly looking forward to the installation day.
Passive flood protection solutions are the most effective when dealing with flash flooding, however Aquobex can also work within given parameters to find the optimal solution to match the flood type with warning times, building structures and people issues. All of these are an important part of the solution provided.
The final part will be to deliver a Flood Emergency Response Plan (FERP) to the customer at the end of the project, so the on-site team is always briefed and aware of their actions when the next flood event occurs.
The solution for the power room vent was concluded as a FloodBreak flood vent, because this is the most critical part of the flood solution and a passive product was highly desirable from the start.