If you asked most people what they thought the biggest causes of bridge failures were, they’d probably think of accidental impacts or physical deterioration of the structure. Few would think to look down to observe the scouring action of the watercourse being spanned. Yet that is often the root cause of the problem.
Similarly with embankments. The effect of inadequate drainage at the base of the structure can be catastrophic, which may not become apparent until the water evaporates or drains away and saturated soil suddenly dries out. Effective water management is critical when designing effective emergency responses and temporary works. It’s absolutely essential when it comes to ensuring long-term resilience of many rail assets.
Water, Water Everywhere
Inadequate water management has other potential consequences, from track being destabilised by ballast wash-out, to short-circuits cutting power to trackside points, signalling equipment and conductor rails.
Logging where water is present, how it flows and where it’s likely to collect is always a priority, whether we’re called to an emergency response or involved in designing preventative maintenance interventions. Better understanding of water management also helps direct maintenance investment to locations at greater risk where it will deliver the biggest resilience benefit to the network.
Yet the influence of water management isn’t always fully appreciated. At Langport embankment, the permanent works design made no provision to retain the embankment at the intersection with the adjacent River Parrett viaduct structure. This risked destabilising the slope in this location.
Our early-stage design review as part of our projects: simplified approach picked up the issue – so a solution could be agreed with the client’s designer without affecting the programme.
New Challenges, New Solutions
Our changing climate is pushing water management capabilities to the limit. We’re often designing for conditions that we expect to be more extreme than in the past. And we always have to be conscious that water diverted from an asset ends up somewhere. We can’t solve one problem by creating another for somebody else. All of which calls for constant innovation and exploring alternatives such as sustainable drainage (SUDS).
The value of water management capabilities can be measured in faster emergency responses, greater long-term value from a finite maintenance budget, and fewer days of lost revenue due to failures and flooding.