'Rethinking Water' URBAN DESIGN 178 Topic Introduction

Welcome to this deep dive into the topic of water. This edition discusses new ways of looking at water: as a resource, as something to value, and - as ever - something to manage. For millennia, farmers have wanted their land to be drained and more productive, and merchants have built docks and warehouse over mudflats. We can’t begrudge or change the past, but now we understand that canalising and speeding up rivers, building on floodplains, and treating rivers as sewers has consequences.

Cambridge: Clay Farm, Trumpington is a case study of water reuse development. Images courtesy of enabling Water Smart Communities (EWSC) Programme.

At a recent packed-out conference on the reuse of grey and rain water, one speaker noted, ‘A couple of years ago it would have been one man and his dog in here!’ Concern about water quality, especially in rivers, now receives wide spread media attention. Practitioners who have been working passionately in the field for decades are delighted, if a little bemused, that suddenly politicians and the wider public have started to notice its importance.

Almost any film or TV scene with people walking along the River Thames will have St Paul’s Cathedral and the city in the background, actors leaning against railings with the water lapping below. Hiding in plain sight, this landscape includes an early (late 1990s) attempt to reunite a river with its floodplain. Between the Globe Theatre and Blackfriars Bridge, the line of flood defence was retreated from a concrete wall along the river’s edge, and now sits 50m back, running imperceptibly across the Tate’s front lawn.

Built environment professionals have a key role in helping to ensure that our waters are as healthy as possible, while also reducing flood risk and enhancing biodiversity, and at comparable or often lower cost. In this issue we get a taste of some of the innovation taking place; for example in sustainable drainage, water reuse and the design of new reservoirs. We look at ‘lost’ rivers, and responses to devastation from flooding in New Orleans and Jakarta. Perhaps another time we’ll talk about beavers, nature’s great water engineers.

A couple of years ago, I attended a council-run session for developers and architects about design quality and what the public and private sectors needed from each other. During the event, a Slido poll asked the room for their number one barrier to getting things done. Expecting the typical moan about planners and planning, it was a surprise that the answer was sustainable urban drainage schemes (SuDS), and the explanation was simply down to land take. This was a brutally honest glimpse into the developer’s mindset in that many will take a site’s red line boundary, work out the number of units deliverable, and only think about drainage at the end. From that starting point, they have to lose a few units to squeeze in a pond, and this is seen as taking a hit to the scheme’s profitability.

Even development schemes which were radical and innovative in their time would be conceived very differently now: Bazalgette’s London sewers and embankments have most certainly transformed London for the better, but their design combines sewage and rainwater in vast quantities. This mixing of water is a key factor behind why our waters are in the state they’re in – when it rains heavily, the ‘safety valve’ is for the ‘combined sewage overflows’ (CSOs) to release the excess into rivers. This is what they were designed to do (preferable to flowing backwards out of your loo), but heavier rainfalls and increased development areas mean this is happening more often. Overall, agricultural runoff also has a similar impact on poor water quality. This sector, plus highway or surface runoff, are rapidly attracting more attention, along with emerging challenges including chemical pollution such as from pharmaceuticals and PFAS (i.e. Perfluoroalkyl and Polyfluoroalkyl Substances, the so-called forever chemicals).

Much is also being done through voluntary organisations, for example through the Rivers Trust movement – a network of 65 organisations across Britain and Ireland. These trusts are investing in natural flood management and river restoration schemes, and mobilising volunteers, including in citizen science water testing and pulling out invasive species.

There are probably three key pieces of advice that anyone in the water sector will tell that you they want from the built environment world: one, for water resources and drainage to be considered from the very beginning of project inception; two, for concepts like water reuse and SuDS to be considered mainstream and not unusual one-offs; and three, that the best place to deal with a drop of water is where it lands. Oh, and - never flush a wet wipe!

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