With weather patterns changing dramatically, a water management firm has urged highway and civil engineers to use nature-based solutions and sustainable drainage systems (SuDS) to conserve water, create resilient sites and support biodiversity.
ACO Water Management pointed out that while England had its joint hottest summer on record, with eight areas officially declared as being in a drought in August, thunderstorms and heavy downpours battered the UK throughout September, while trends from the latest State of the UK Climate Report point towards a growth in frequency and intensity of rainfall across the UK.
ACO sustainability lead Adam Cane said highway developers should create systems that better conserve water when droughts and storms hit, including using SuDS and nature-based solutions to retain water as high up on site as possible and protecting sites by incorporating water cleansing solutions into highways and infrastructure projects.
He said: ‘The UK’s climate is changing rapidly and we’re seeing more regular cycles of extreme weather events. This is creating two challenges. Firstly, sites are starved of water and biodiversity suffers as a result. Secondly, flash floods and downpours mean large amounts of stormwater enter our systems and may bypass treatment, which can then mean harmful pollutants get washed into the surrounding ecological systems.
‘This is something that needs to be considered early in the design by the construction industry and there are ways in which highways professionals can help protect our environment. The key to any new site development is to limit our intrusion into nature wherever possible and keep as much of the natural environment in place.’
ACO StormBrixx is a patented plastic geocellular stormwater management system
Mr Cane said trees and green areas should form the backbone of new project design and be prioritised to help safeguard ecological site characteristics, connectivity and help lower carbon. These areas offer shade, amenity, natural air conditioning and refuge opportunities for wildlife.
Meanwhile, SuDS solutions, such as bioretention areas, rain gardens, swales and tree pits, can take runoff from hard surfacing and roads and store them at source to create resilience and slowly feed them back into the ground and waterways, rather than into sewers. Exposed water cools the surrounding environment and offers opportunities for amenity and biodiversity.
Mr Cane said: ‘Crucially, for dealing with extreme events and where above ground space is restricted, SuDS features and nature-based solutions can be coupled with underground geocellular storage tanks, creating resilience and allowing for long term infiltration.
‘Space is often one of the key barriers when incorporating SuDS on sites, especially when dealing with pollutants. Roads offer particular challenges due to the volume of pollutants. Here proprietary solutions, such as oil and heavy metal separators, are beneficial, as they can protect natural systems. Clean water is essential for nature.’
ACO said its range incorporates solutions from the full SuDS management train. This includes proprietary products that work to protect natural systems, such as its V-Septor and QuadraCeptor. These products help clean the water before it is released into the soil or watercourse.
It said both ranges meet with the guidance from Design Manual for Roads and Bridges (DMRB) document, CD 528 Vortex separators for use with road drainage systems, and designers should refer to the CIRIA SuDS Manual (C753) when looking at SuDS schemes.
The October issue of Highways magazine includes a feature from Terry Wilkinson of ACO on SuDS and nature-based solutions.
