Flooding – when disaster strikes

With the recent issues caused in the Derbyshire town of Whalley Bridge – which underwent a full evacuation after a damaged dam was declared unsafe amid fears torrential rain would cause the dam to burst – operations director Andrew Greatorex looks at the possible cause of the drama at Toddbrook Resvoir and how DASA can assist when disaster strikes.

When the recent drama at Whalley Bridge was developing, a lot of my friends and acquaintances who are aware of my work in the drainage sphere would approach me and say ‘ooh, well at least you’ll be busy’ when talk turned to the prospect of millions of gallons of water torrenting through the Derbyshire town.

Comments along the lines of the above were made so often, and I set about explaining where we might actually have had some input on the whole thing so many times that in the end I took to just saying ‘yeah’. The truth of it is that, actually, flooding when it comes on the scale that Whalley Bridge was being braced for, has very little to do with drainage either as an antagonist or as a potential saviour. Where drainage plays its part is in the aftermath when the devastating volumes of water have receded and the aftermath is being faced. It’s here that our ability to inspect, diagnose and, crucially, clean and clear, drainage pipework comes to the fore.

Thankfully, Toddbrook Reservoir (which is the body of water held back by the dam at Whalley Bridge) never did give way, but had it done so then we would have been in a position whereby the drainage provision serving the town would be tested far and away beyond any ‘planned’ extreme.

This is not a once in ten years storm, or a once in a generation ‘Michael Fish’ of a hurricane. This would have been a truly unprecedented incident whereby in the blink of an eye 283 million gallons of water was released, immediately overwhelming rivers, streams, culverts and, yes, drainage systems. There’s nothing a drainage response crew can do to prevent that, no matter how many rods they carry or how big their jetter is!

Where there has been a disaster of this type, whether natural due to the huge storms that seem to be increasing in incidence, or ‘man made’ as might have been the diagnosis of the failure of a dam (whether the storms themselves are man-made is perhaps the topic for a future ‘blog).  DASA is there to limit insurers’ exposure to ancillary costs, to direct operations from the ground and pass information ‘back up the chain’. Taking action to prevent any subsequent flooding or malfunction that might stop insurers’ attempts to get homeowners back into their properties, in the shortest  and safest timescale permitted limiting the distress, and loss of utility and / or earnings.

In the event of a true ‘disaster recovery’ scenario, DASA has drawn up a five-stage plan which we believe ensures the quickest and most efficient response to a serious flood event and its immediate consequence:

1. DASA is mobilised following the return of homeowners to their properties. Our remit would be to establish a working compound at the site of the flood event, allowing senior staff to project-manage the exercise(s) to come, and to coordinate with other members of the insurers’ supply chain; loss adjusters, structural surveyors, disaster recovery and insurers themselves.
2. DASA brings the expertise and tanker resources on clearing away the thousands of tonnes or silt and sludge deposited within infrastructure, ensuring that the pipework laying below affected properties is clear and able to accept any ‘normal’ rainfall and domestic discharge following the flood event. We would be there to ensure that the insult of – for example – surcharge from a WC would not be added to the potentially grievous injury of the previous flooding.
3. Following, and in support of, the debris removal operation, DASA’s CCTV survey systems are deployed throughout the various apparatus to identify, locate and diagnose any damage to the infrastructure, whether consequential or coincidental to – in this instance – a dam’s failure.
4. Acting as a central base of operations, the on-site management resource plans and executes repairs in line with insurers’ direction. This allows the teams on site to act as a single entity, with resources diverted between discrete sites on a need must basis, whilst maintaining a hands-on immediacy to response in line with the quickly-changing demands of what would remain a developing situation.
5. Finally, DASA will be in a position to present a holistic report on the event, with over-arching site-wide ‘macro’ findings and opportunities for learning layered in with individual and property-specific ‘micro’ diagnoses, works and completion notes.

DASA can’t prevent the incident that leads to the damage in cases like that so thankfully averted with Toddbrook, but we pride ourselves on having the equipment, expertise and experience to make sure that a flooding disaster doesn’t become an ongoing drainage crisis.

For further details on the service that we provide please get in touch.