GET READY FOR SUSTAINABLE URBAN DRAINAGE

Following a review into surface water management by the Department for Environment, Food and Rural Affairs (Defra), the Government has announced plans to make sustainable drainage systems (SuDS) mandatory for all new developments in England. Here, Dr Netsanet Mebrate, Causeway Flow Product Owner, discusses tips for implementing SuDS and explains how technology can help with its design.

The new regulations are expected to come into force in 2024 – five years after they were introduced in Wales to reduce flood risk and improve water quality.

Some regions in England, including Cambridgeshire and Oxfordshire, have already implemented a mandate for SuDS. However, there is still work to be done to encourage the adoption of SuDS more widely.

Drainage is now a top priority in the construction design process and the mandate announcement has placed added pressure on contractors to explore the possibilities of installing SuDS on all new sites.

Rethinking SuDS

Sustainable drainage expert Anthony McCloy argues that we need to change our attitude towards rainfall and, rather than view it as an issue – something that must be addressed to meet a planning condition – we should embrace it as an asset and make it a critical consideration in planning and design stages.

According to Anthony, by harnessing rainfall as an asset, developers can improve climate change resilience, facilitate biodiversity and create more interesting, useable and multi-functional amenity spaces.

He says if we can replicate what the National Planning Policy Framework (NPPF) is telling us and acknowledge what the guidance is there to relay, keep the water at source and allow it to slowly move through the site, it becomes something that’s much more in keeping with the local landscape and a real asset.

What’s more, all the research that’s been done to date shows that SuDS don’t cost more – they can either be cost neutral or even cost less than traditional drainage solutions.

Tips for implementing SuDS

It’s true that SuDS should inform the layout of a development. However, they should also be informed by the layout. Developers shouldn’t get as far as the detailed design stages before they decide they need to implement SuDS.

There is a wide range of data that can inform SuDS design and flood risk assessments, from planning information that planners would use as a screening tool, to more detailed data that can be accessed via the Government website about surface water and reservoirs, so we can understand flooding from a variety of different mechanisms. www.causeway.com/products/drainage-design

It is also possible to access Strategic Flood Risk Assessment –site-specific flood risk assessments – and look at all the documents the local authority may have, such as the Local Flood Risk Management Strategy (2019-2029), which may contain data about particular areas of flood risk that might not be representative within the modelling.

How technology can help with the design of SuDS Technology exists to support the design of SuDS, including Causeway’s Flow. Developed for organisations looking for a robust, intuitive and complete solution, Flow is a hydraulic modelling solution for the design and analysis of optimal, compliant and cost-effective storm and foul water drainage networks.