Swale in new housing development. Credit: Sue Illman

Ministers mustn’t repeat past mistakes on crucial flooding law

Energy & Climate Change, Flooding, Management & Regulation, Natural Environment

Ministers mustn’t repeat past mistakes on crucial flooding law

A little-known component of the Flood and Water Management Act – passed into law in 2010 but never implemented and currently being reviewed by Ministers – is pivotal to the current sewage crisis and our ability to manage climate change-exacerbated flash flooding.

What made sense more than a decade ago has been underlined by recent sewage spills and flooding. Government mustn’t repeat its past mistakes and this time must implement Schedule 3.

In summer 2007, deluges put 55,000 households under water and knocked out water and power supplies for weeks. The worst summer floods in living memory prompted government to undertake a major independent review of flood risk management.

The Pitt Review made over 90 recommendations for improvement, the most pressing taken forward in the Flood and Water Management Act 2010.

A small but crucial schedule of that Act – Schedule 3 – considered Sustainable Drainage (commonly known as SuDS). It recognised that conventional piped drainage was becoming overwhelmed by growing intensity and duration of rainfall.

Rooftops, patios, driveways, roads and pavements associated with new development were all reducing the ability of the ground to soak up increasingly intense rainfall. A different approach to managing this kind of flood risk – surface water flooding – was needed.

Schedule 3 proposed that an automatic right held by developers to connect new housing or other developments into existing drainage networks without restriction should be removed, so that these systems didn’t get overwhelmed.

Developers would still be allowed to connect, but on condition that they should incorporate SuDS features which temporarily store or slow down rainwater during storms before releasing it slowly either into the network or by helping it to soak straight into soil and groundwater.

Local authorities would review drainage plans for developments and approve them against nationally agreed standards. In return, they would adopt the features and maintain them.

A weakened approach

Housebuilders objected on the grounds that this new approach was supposedly more difficult and expensive and would be a blocker to the pace of housebuilding; a perennial concern for any government.

In 2014 then Housing Secretary Eric Pickles confirmed that schedule 3 would not be commenced and SuDS would be encouraged through the planning system in a more streamlined approach.

Loopholes in this planning-led approach were such that many developers got away without ever including SuDS in developments. Where they were included they were often poorly designed, and were commonly never adopted and maintained so didn’t work as required.

As a result, the impact of new development on flood risk to local and downstream communities remains inadequately managed. Flood risk managers fear the kinds of events which have caused devastation in Germany and Canada in recent years could all-too-easily happen here. The deluges in July 2021 in London perhaps a warning, when miraculously no one died in flooded basements.

And as keeping climate change below 1.5oC becomes an ever-more fleeting hope post-COP27 and we need to prepare for far worse extreme weather there is a real risk government, pushed again by housebuilders, will sit on its hands after the latest review of whether it should finally implement this law.

Evidence on costs and benefits

Countless expert reviews have recommended that Schedule 3 should be commenced. Government’s own climate and infrastructure advisers have warned that more commitment is needed to tackle surface water flooding as the biggest source of risk to over 5 million households.

The National Infrastructure Commission will set out its stance on managing surface water flood risk in the results of a focused study next week. This is an important, and growing issue.

And despite housebuilder concerns on cost, or myths around the amount of land taken up by SuDS features, experience shows that where SuDS are well-designed and planned from an early stage they can often be cheaper to build and maintain – not least because they aren’t buried below ground.

Costs to over-stretched local authorities in maintaining SuDS are also flagged as a concern. And government may point to its current £5.2bn flood defence programme as a means of managing the problem. Yet research currently being finalised by CIWEM shows that lead local flood authorities are struggling to access this money effectively enough to keep on top of the problem.

Next year the government is due to publish its latest National Adaptation Programme – a five-yearly plan for how it believes the nation should adapt to the growing extreme weather impacts of the climate crisis. Ministers’ decision on Schedule 3 will be an early signal of how seriously government takes this challenge and is prepared to ensure new development builds climate resilience rather than lowering it.

Multiple benefits

And fundamentally it’s not just about climate and flooding. The sewage spills which have become a focus for huge public concern and projected massive water company investment to clean up, are partly caused by the progressive increase in load put on drainage networks by new development.

Combined sewers, which carry ‘foul’ sewage and rainwater together are at the heart of this problem. New development can still automatically connect to them, with SuDS still an afterthought or nice-to-have. So the pressure on the system grows and whilst water companies may spend billions of pounds of bill-payers’ money on new treatment works and tanks, a 12-year old piece of law which could help tackle the problem upstream remains un-enacted.

This can’t be allowed to happen again. Over the last decade, awareness of the extent of sewage in our rivers, seas and on our beaches has become widespread. And the extremes of climate change are playing out across the country. Meanwhile, more than 1.5 million new homes have been built without this important law being applied to them.

Ministers may be concerned about how housebuilders can cope with Schedule 3, Biodiversity Net Gain (BNG), Nutrient Neutrality and more as pressures on the environment from development come to the fore.

But most of these approaches are complementary. Whilst new and different, they're not inherently difficult. And SuDS can help achieve BNG and Nutrient Neutrality within developments. They can also achieve far wider benefits - to air quality, wider water quality, mental and physical health and wellbeing and more.

So, government can either choose to require housebuilders to build in a way which is resilient to growing climate and pollution pressures, just as they are rightly demanding water companies must do with their infrastructure.

Or, they can sit on their hands, knowingly add to the problem and leave society to pick up the pieces and bill further down the line. This approach isn't rocket science and could have been mainstreamed many years ago.

Now, after a decade of proving it's the right way to go, it's time to reap the benefits and implement Schedule 3 of the Flood and Water Management 2010.

Alastair Chisholm
Director of Policy, CIWEM

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