It won’t have escaped your attention that this summer, at least in the UK, was a little damp, and autumn has followed a similar trend so far. With numerous flood warnings issued and talk of ‘a month’s rain in one week’ according to the BBC, it appears that flash flooding is becoming a regular occurrence for our summer months. With eyes on the skies, it’s also crucial to consider the ground under our feet – namely the roads we use and the infrastructure surrounding them, including our drainage network. As the clocks change and British Summer Time comes to an end, it seems like the ideal opportunity to take a look back and review the risks associated with summer rainfall.
The effects of climate change
Scientists have warned that flooding in the UK is becoming more frequent as a result of climate change. Climate meteorologists have predicted changes in weather patterns, with rainfall intensity and flooding events becoming more frequent. Flooding from intense summer rainfall will become more common, and its impact will be felt across the highway network.
National Highways has prepared a report assessing the impacts of climate change on the strategic road network, aiming to build future resilience. This acknowledges the potential for more intense summer rainfall events, increasing the risk of waterlogged roads set against either saturated verges, or excessively dry verges where water may not be absorbed should a rainfall event occur after a period of high temperatures. Their response to climate change sees them working with partners such as the Environment Agency to protect homes from flooding, alongside updating their standards for road design and regularly assessing and identifying high-risk areas.
Elsewhere, in Scotland, highway chiefs brought forward their gully cleaning programme to alleviate the flooding in Inverness. Susceptible to flash flooding, a section of the A9 was prioritised for gully work, and further improvements are also now being investigated.
Many local authorities are now highlighting the impact of summer thunderstorms and heavy rainfall on our highways. Whilst essential for maintaining vegetation growth and replenishing water sources, it’s widely acknowledged that it can wreak havoc on the roads. Exposure to moisture can weaken foundations, leading to erosion and instability, as well as increasing the speed of surface degradation, as rainwater seeps into cracks and weakens the underlying layers of the road. This may well lead to an increase in potholes during the summer months, bringing a year-round pothole problem, normally only witnessed during winter. This could have a knock-on effect on maintenance programmes, with pothole crews required year-round, rather than focusing on different tasks during the summer months. And, of course, flooding and extended water pooling on the road surface will have an impact on the drainage maintenance, with local authorities needing to review their approach.
Searching for a solution
It is widely acknowledged that future measures will be required to mitigate the effects of increased summer rainfall. National Highways has allocated over £420,000 to 13 natural flood management projects in northwest England, aimed at mitigating flood risks. These include planting woodlands and hedgerows, building ponds, soil aeration and creating natural barriers to water flow called ‘leaky dams’. These projects will help to direct the rainwater that runs off the road, reducing flooding as well as creating areas to enhance biodiversity
As well as this, changes to road construction will be required to improve the performance and resilience of the roads under a changing climate.
We continue to advocate for a risk-based approach to drainage management, streamlined by our Gully SMART solution. Increasing productivity and efficiency, Gully SMART software helps accurately monitor the condition of the drainage network, so that issues can be resolved swiftly, and a more efficient drainage maintenance programme can be created.
As our climate changes, our approach to maintenance needs to change with it. For more information on how KaarbonTech is helping local authorities implement a risk-based approach to drainage management, see our website.