Canary Wharf

How our internal drainage experts solved an ongoing issue that was seriously disrupting the headquarters of a FTSE 100 financial services firm.

The site: the global headquarters of a major investment bank. This landmark tower is 156m tall, with 32 storeys and almost 1.7 million sq. ft. of floor space.

The problem: repeated internal blockages across multiple floors and stacks, leading to system shutdowns, flooding and 4+ call-outs every week.

Detailed investigation and phased solutions

The Metro Solution


Our surveying team created a detailed internal schematic, enhancing existing plans

We heat-mapped incidents in real time as they occurred to identify problem areas

We laboratory tested water samples from across the building to diagnose the issues on a chemical level

We interviewed surveyors to understand the building’s design capabilities


Our initial findings suggested three key issues:

  1. The system was designed for 60% of the current capacity
  2. Overcapacity was compounded by hard water scale issues 
  3. There were several crowded floors that accounted for a disproportionate share of call-outs

We therefore pilot-tested small dosing units on each floor, free of charge to the client


Our dosing unit trial was launched for a three month period

Our engineers gathered data throughout this period to monitor our approach

At the same time, we initiated a rigorous clean of the internal infrastructure, using state-of-the-art mechanical coring equipment

The final phase was to bring the building onto a biannual planned maintenance program

Dramatic reductions in reactive costs

3 month reduction in call-outs on 3 problematic floors

12 month reduction in reactive spend across the whole site

Source: internal company data; reactive costs based on historic average reactive charge value of £933 per job

The initial pilot trial, which took place on 3 highly-problematic floors, showed a 74% reduction in reactive issues, with only 5 call-outs in the 3 months following the dosing implementation, versus 19 in the previous quarter.

In the 12 months following our implementation, we saw a building-wide reduction in reactive spend of nearly 70%, which we estimate represents an annual saving of in excess of £60,000

We have since continued to implement our robust PPM regime, carrying out extensive internal cleaning using Picote’s MaxiMiller coring equipment, and reactive callouts remain at consistently lower levels