Our sewage works is already spilling. They want to plumb another 456,000 homes into it.
Every new estate connects to a treatment works that already exists. In most of our towns and villages that works was built for a population that stopped being accurate decades ago, and its overflow record is public — and the same rivers Anglian Water describes as being at exceptionally low levels are the rivers the overflows discharge into, which is why a spill in July does far more damage than the same spill in February.
Why the works never gets upgraded
Treatment capacity is lumpy. A works either has headroom or it needs rebuilding, and rebuilding is a capital project sized in years and tens of millions. A hundred and fifty houses cannot trigger one — it can only consume the headroom that is there. The next hundred and fifty consume a little more. Eventually there is none, and the overflow starts operating as designed: as a relief valve, more often, for longer.
Nobody in the chain has done anything wrong. The developer paid what was asked. The council granted what the plan allocated. The water company planned on the cycle it plans on. And the river gets worse every year, because no single decision in that sequence was ever large enough to require a new works.
The turn
Concentrated development is the only kind that ever comes with a treatment works attached. Build twenty thousand homes in one place and a new works is not optional — it is a condition of the thing existing. Build the same twenty thousand across a hundred villages and not one will ever be asked for a works, because not one is big enough to be asked.
By district — 2025 spill hours
Across these districts in 2025: 9,546 counted spills lasting 55,248 hours, from 985 monitored overflows within 20km of a town or village on our list.
| District | Spill hours | Spills | Worst works |
|---|---|---|---|
| Huntingdonshire | 14,430 | 1,962 | RAMSEY WATER RECYCLING CENTRE (1,432h) |
| North Hertfordshire | 7,655 | 717 | MARKYATE WASTEWATER TREATMENT WORKS (3,531h) |
| East Hertfordshire | 4,954 | 732 | Theydon Bois (635h) |
| South Cambridgeshire | 3,652 | 396 | Foxton (Cambs) WRC (1,645h) |
| Chelmsford | 3,468 | 522 | WILLINGALE WWTW (1,078h) |
| Mid Suffolk | 3,299 | 414 | DICKLEBURGH WATER RECYCLING CENTRE (564h) |
| Fenland | 3,065 | 661 | CROWLAND STW (461h) |
| East Suffolk | 2,767 | 1,240 | CAISTER- HEADWORKS PS (412h) |
| Uttlesford | 2,670 | 354 | ABBESS RODING WWTW (683h) |
| East Cambridgeshire | 2,418 | 416 | WITCHAM STW (615h) |
| Maldon | 1,514 | 509 | SOUTHEND SEWAGE WORKS (237h) |
| West Suffolk | 1,415 | 177 | HUNDON WATER RECYCLING CENTRE (300h) |
| Braintree | 1,341 | 289 | WHITE NOTLEY WATER RECYCLING CENTRE (229h) |
| Tendring | 1,063 | 371 | CLACTON (HOLLAND HAVEN) WRC (274h) |
| Colchester | 556 | 291 | SPORTS CENTRE MILL RD. (107h) |
| Ipswich | 553 | 349 | IPSWICH-CLIFF QUAY WRC (307h) |
| Babergh | 430 | 146 | HOLBROOK STW (63h) |
| Cambridge | 0 | 0 | CAMBRIDGE RIVERSIDE 187 CSO (0h) |
Source: Environment Agency / water company EDM Storm Overflow Annual Return 2025 (Anglian Water + Thames Water sheets; overflows within 20km of a listed settlement).
Questions
- Isn't sewage a water company problem, not a planning problem?
- Both, and they are barely connected to each other — which is the problem. Water companies plan on their own investment cycles. Councils allocate housing on theirs. Nothing obliges the two timetables to meet, so homes routinely arrive years before any capacity does, if it arrives at all.
- So you want to stop new connections?
- No. We want new homes built where a new works comes with them. That is normal at new-settlement scale and impossible at village scale.
- Aren't storm overflows being cleaned up anyway?
- There are programmes and they matter. They are also sized against today's connected population. Every estate approved without a matching upgrade quietly moves the target while the programme is still chasing the old one.
- Our village is on a septic tank — does this affect us?
- Often more, not less. Growth that pushes a village past the point where private systems cope creates pressure for a connection that may not exist, and small package treatment plants serving new estates have their own consenting and capacity limits.
- So you're just NIMBYs.
- We are arguing for building homes in places that get a treatment works built with them. That is more housing infrastructure, not less.
- Where would you put them instead?
- Somewhere large enough that a new works is part of the deal. Scattered growth never assembles that obligation. Concentrated growth does.
- Where do your figures come from?
- Event duration monitoring returns for 2025 (Anglian Water and Thames Water sheets), assigned to districts by proximity to towns and villages on our list, plus the government's standard method for housing need. If we have got something wrong, email corrections@stopurbansprawl.uk and we will fix it and say what changed.
What's planned near us?
Find the district page for where we live.
All infrastructure topics · The numbers · Corrections
It's clear we don't have enough infrastructure already. So how can the government expect to build another 1,367,880 homes?
Sign the petition to stop urban sprawl
Sign the petition to stop urban sprawl. We'll email about development in this area and related updates. You can unsubscribe from any email. We don't sell or share the list. More about how we use details.