{"id":152636,"date":"2025-09-02T15:02:56","date_gmt":"2025-09-02T14:02:56","guid":{"rendered":"https:\/\/greenblue.com\/?p=152636"},"modified":"2025-09-02T15:04:18","modified_gmt":"2025-09-02T14:04:18","slug":"drought-today-deluge-tomorrow-but-theres-a-solution-for-climate-whiplash","status":"publish","type":"post","link":"https:\/\/greenblue.com\/gb\/drought-today-deluge-tomorrow-but-theres-a-solution-for-climate-whiplash\/","title":{"rendered":"Drought today, deluge tomorrow \u2013 but there\u2019s a solution for climate whiplash"},"content":{"rendered":"

It wouldn\u2019t be a British summer without a crop of news platform articles about how hot, cold, wet or dry it is. And there\u2019s more to hit the headlines than in the past, too. Britain\u2019s summer weather patterns \u2013 so long associated with rain that jokes about a Bank Holiday correlating with a certain downpour are familiar to everyone \u2013 are changing. Indeed, so are the patterns throughout the year.<\/strong><\/p>\n

The new normal is effectively climate whiplash. Long, hot spells bake soils, after which the first proper downpour sheets off pavements and compacted verges, overwhelming drains that were already struggling. When that first storm hits, rainfall intensity outpaces what hardened, hydrophobic soils can absorb and what gullies can carry; water skims across hard surfaces, concentrates along kerb lines and cambered roads, pools at low spots, and in minutes puddles appear and grow as the local drainage network backs up. This flow simply overtops the kerb into shops and homes: a flash flood. Cue more click-worthy headlines (as well as lots of disruption for homes and businesses).<\/p>\n

The answer isn\u2019t to increase sewer capacity, and it\u2019s not even solely to remediate aging infrastructure, it\u2019s to take an entirely different approach to drainage infrastructure.<\/p>\n

Sponge cities for climate change resilience<\/strong><\/p>\n

We need to redesign our streets to store, slow and soak. So-called \u2018sponge cities<\/a><\/strong>\u2019 use distributed green-blue systems \u2013 including tree pits<\/a><\/strong>, permeable paving and linked raingardens<\/a><\/strong> \u2013 that intercept runoff at the surface, hold and meter it, strip out first-flush pollutants, then pass only safe flows to the network. In dry spells some sponge city elements passively irrigate trees (which help cool pavements); in downpours the nature-based drainage provides staged overflows and clear exceedance routes. Modular, retrofit-friendly and easy to maintain, this is budget-friendly resilience you can build one block at a time.<\/p>\n

The cost of doing nothing is very likely to be significant, as the scientific evidence for this problem to only increase is pretty unequivocal.<\/p>\n

The Met Office<\/a><\/strong> now puts the chance of another 40\u00b0C UK day at roughly 50\/50 within 12 years, and says temperatures several degrees higher than 2022\u2019s record are now possible. Hotter spells don\u2019t just test people; they desiccate soils and hard surfaces, priming them to resist water infiltration when rain returns. At the same time, attribution studies show human-driven global warming is already increasing the intensity of UK storm rainfall. Put those two trends together and the solution becomes clear: cool streets during drought; attenuate water during cloudbursts.<\/p>\n

Policy is finally catching up. England\u2019s National Standards for Sustainable Drainage<\/a> (SuDS) \u2013 published in June and updated in July this year \u2013 set an outcomes-led bar: manage peak flows, treat water quality, deliver amenity and biodiversity, and prove the system can be maintained and (crucially) adopted. This is not a tick-box exercise, it\u2019s a nudge in the right direction to re-cast approaches to drainage infrastructure that can handle both heat and cloudburst, solving both challenges with a single solution<\/p>\n

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Street trees to cool, store, release<\/strong><\/p>\n

Trees are central when they\u2019re treated as infrastructure, not ornaments. Healthy urban trees cool through shade and evapotranspiration; the evidence base on their microclimate benefit is solid. Pair that biology with engineering \u2013 root-friendly soil volumes in structural cells, oxygenation, controlled inlets from kerb or slot drains, and a throttled outlet to the next SuDS stage \u2013 and a street tree becomes a discreet detention basin under the pavement. The usual objections don\u2019t stand up when designs are competent, too. Root barriers manage conflict with utilities and paving, leaf guards and pre-treatment baskets keep inlets clear, and exceedance routes are a standard part of any credible drainage submission.<\/p>\n

The key ingredients of the optimal design are practical, straightforward and repeatable:<\/p>\n