Why it keeps happening

Dry spilling

A spill in dry weather has no rainfall to excuse it. The same overflows do it year after year.

Overview Dry spilling Before the works Treatment works capacity

The test that applies

A storm overflow may discharge only in exceptional circumstances. Regular spilling in normal or moderate rainfall is a prima facie breach of regulation 4 of the Urban Waste Water Treatment Regulations 1994.

This reading follows the Office for Environmental Protection's December 2024 findings against Defra, the Environment Agency and Ofwat, which set out a two-stage test — was the discharge caused by exceptional circumstances, and was it nonetheless kept to a minimum — and Defra's 24 March 2025 guidance, which supersedes the 1997 guidance the regulators had relied on.

Overflows spilling in dry weather

the same ones, year after year (dry in 2+ of the last 7 years)

Dry spills so far in 2026

no rain to excuse them

2,979

Dry spills since 2020

across the catchment

Have a scheme addressing it

of 25

Repeat dry-weather offenders

Overflow	Years	Dry spills	On record
Kilbury STW, BuckfastleighSSO SBB00178	7	260	Measure linked
Holne STWSO SBB00581	6	14	No measure
Scorriton STWSO SBB01058	5	154	No measure
Totnes STWSSO SBB01264	5	61	Measure linked
Cornworthy STW, DartmouthSSO SBB00309	5	32	Measure linked
Scout Hut, Stoke GabrielCSO SBB01060	5	20	Measure linked
Rattery STWSO SBB01016	4	1,775	Measure linked
Harbertonford STWSSO SBB00537	4	78	Measure linked
Harberton STWSO SBB00535	4	75	Measure linked
Harberton STWSSO SBB00536	4	67	Measure linked
Dartington Sch TwoCSO SBB00349	4	49	Measure linked
Mill Creek pumping station, DittishamPS-CSO/EO SBB00776	4	14	Measure linked
Kilbury STW, BuckfastleighSO SBB00179	3	84	Measure linked
Broadhempston STWSSO SBB00165	3	56	Measure linked
Dittisham Main STWSO SBB00365	3	33	Measure linked
Lower Ferry pumping station, KingswearPS-CSO/EO SBB00712	3	26	Measure linked
Warfleet Creek pumping station, DartmouthPS-CSO/EO SBB01316	2	41	Measure linked
Ferry Boat pumping station, DittishamPS-CSO/EO SBB00446	2	37	Measure linked
Yarrow Bank pumping station, KingswearPS-CSO/EO SBB01385	2	22	Measure linked
Ashprington STWSSO SBB00053	2	22	Measure linked
Smith St, DartmouthCSO SBB01095	2	21	Measure linked
Widecombe STW, Widecombe in the MoorSO SBB01359	2	13	Measure linked
Mayors Avenue pumping station, DartmouthPS-CSO SBB00755	2	12	Measure linked
Townstal Tank, DartmouthCSO SBB01269	2	3	No measure
Stoke Gabriel pumping station, TotnesPS-CSO/EO SBB01178	2	3	Measure linked

Each overflow's per-spill confidence (gauge proximity, antecedent-dry window, monitor uptime) is shown on every event's evidence dossier.

How we decide a spill was dry

A spill is counted as dry when rainfall at the nearest gauge was ≤ 0.25 mm on the spill day and the day before, and the spill lasted at least 15 minutes. Confidence rises with a closer gauge, a longer antecedent-dry window, and a monitor that was reporting reliably. Read the full method →

Why this now carries more weight

A dry-day spill is a pollution incident regardless of its volume. Dry-spill frequency is a scored metric in the Environment Agency's 2026–30 regime, and updated incident guidance removes companies' former latitude to downgrade these events. A pattern of them is exactly what a regulator is now expected to act on.

Dry-spill method ↗ · figures reproducible against the pinned method version.