A systems approach on storm overflows: Ten things government’s reduction plan should do

This spring government is consulting on its Storm Overflows Reduction Plan and water companies have been told by Ofwat to publish their own plans for improvement. Water Minister Rebecca Pow has vowed government will look at the “really big picture” on water management. So how big is really big? And who will pay and how much?

CIWEM director of policy Alastair Chisholm sets out ten big picture asks on overflows, which have been made in CIWEM’s new report: River water quality and storm overflows – a systems approach to maximising improvement.

The headlines from Minister Pow are encouraging. On storm overflows, we know wider issues such as a review of Schedule 3 of the Flood and Water Management Act and consideration of a ban on plastic-containing wet wipes are taking place, in addition to the requirements for water and sewerage companies (WaSCs) to set out plans for how they will tackle problematic overflows.

Combined, those bring a water company and flood risk management / development planning suite of measures together which, harnessing Drainage and Sewerage Management Plans and water company business planning, point towards some beneficial progress.

It’s hard to feel that some in our sector – particularly campaign groups – won’t be disappointed by ambition levels but that ambition will be impossible to judge for a while, and will play out over years. In the meantime, timing isn’t good for the optics of throwing loads of money at the problem. With daunting inflation and a rampant cost of living crisis politicians won’t want to countenance adding much more pain through higher water bills.

Which means looking everywhere for the opportunities to improve things becomes more important, even if individually these might not be headline-grabbing actions. With this in mind, here are ten things we’d like government to weave into its “really big picture” storm overflows plan:

1. Water companies to deploy a hierarchy of catchment-wide measures to reduce storm overflows, prioritising nature-based solutions and active system management over underground storage.

Heavy emphasis is being placed on keeping surface water out of combined sewers as a leading way of tackling the problem. Sustainable drainage systems (SuDS) may not always be the cheapest solution, nor fix wider issues like groundwater ingress into sewers. But they will almost certainly deliver the widest range of benefits beyond simply reducing overflows. If investment is going to be made, let’s use an approach which also helps nature, climate, urban diffuse pollution, health and wellbeing where possible before exploring other options.

2. Government to implement Schedule 3 of the Flood and Water Management Act 2010, including mandatory multifunctional SuDS standards, a conditional right to connect development to public sewers and a route to adoption and long-term maintenance.

A mechanism is needed, more than a decade on, to consistently achieve multifunctional SuDS delivery, adoption and maintenance for new developments. The current patchy approach doesn’t. Enough said.

3. Strong regulation by Ofwat and the Environment Agency for PR24 and beyond

Regulators have taken an ear-bashing over storm overflows. Indications are that Ofwat in particular is keen to be seen to be tough following directions to companies on executive pay and production of storm overflow plans in double-quick time. This needs to be carried forward from now on; past pollution misdemeanours by water companies will not be tolerated by a public more acutely aware of the importance of trust in delivering a vital public service.

4. Government to ban plastic in wet wipes

Major manufacturers have either been disinterested in, or disregarded the impacts the design and use of their products is having on the environment, despite the overwhelming scale of the plastic waste problem and the problems with single use products. They block sewers and cause sewage borne litter and microfibre pollution. Hit them with a ban.

5. Government to review the barriers and feasibility to implementing area-based charging for surface water drainage

With such an emphasis on reducing the volume of surface water drained into combined sewers, the ability to provide a price incentive to non-residential customers at least to disconnect their surface water drainage and encourage the use of various SuDS approaches is attractive. Ofwat considers site area-based charging for surface water to be the fairest way to charge, but few WaSCs have implemented it. It’s time to understand why and take another look at the rules and drivers.

6. WaSCs and lead local flood authorities to hydraulically model key catchments to identify optimal opportunities to retrofit distributed SuDS

Pilot studies have shown the benefit in opportunity mapping drainage catchments to identify where distributed, small-scale SuDS schemes can have a collective benefit to flood risk and storm overflow discharges downstream. This picture can help unlock funding streams to aid delivery and should be encouraged in problem catchments.

7. Government to review funding sources and rules to enable grant funding to be pooled and drawn down opportunistically over a period of time

Flexibility can be key in opportunistically enhancing surface water management or water quality outcomes associated with small schemes and works, achieving good value for money by achieving savings on construction when other organisations are also involved. Yet the rules, necessary evidence and timescales associated with applying for grant funding can be prohibitive to the need to be nimble in collaborative local delivery. These rules should be reviewed to understand how they can better support such small schemes.

8. WaSCs to create partnership funding pots for use with local authorities on retrofit SuDS schemes where flood risk is not the primary driver

The ability for risk management authorities to make the best use of flood risk management grants for schemes which are not prioritising flood risk management (but are still beneficial) relies on their ability to secure significant partner contributions under government’s partnership funding rules.

Because there can be synergistic benefits between managing surface water more sustainably for flood risk benefit and in removing it from combined sewers so reducing pressure on these networks, WaSCs should proactively look to make pots of money available to maximise these benefits with partner organisations.

9. Establish a legal duty on highways authorities to seek opportunities to manage highway runoff through SuDS when undertaking other infrastructure or renewal works

Highways authorities have historically not embraced the opportunity to sustainably deal with the large volume of often polluted runoff which drains from roads. Given urban greening drivers, a legal duty requiring them to explore where SuDS could be worked into regular footway or highway maintenance activities, construction of traffic calming or other infrastructure such as cycle lanes would sharpen their focus. This could potentially be included in upcoming levelling-up and regeneration legislation.

10. Local authorities to develop infrastructure coordination services to enable syncronised and coordinated delivery, including of SuDS.

The disruption and inefficiency involved in uncoordinated street works by various infrastructure operators is considerable. Infrastructure coordination teams, such as that run by the GLA in London, may offer potential to achieve more collaboration and synchronised delivery of SuDS alongside other works. Lessons should be sought from this experience and if effective government should seek to encourage similar approaches in authorities nationwide.