Blackbrook North, Princetown
The monitor is reporting and shows no discharge.
The problem here is local, not the works.
This overflow spilled 18 times on days its own treatment works stayed shut — so the works still had capacity. That points upstream, to this branch of the network, rather than to a works too small for its catchment.
How this verdict is reached →Can its works cope?
Full capacity view →This overflow drains to Princetown STW, serving about 1,443 people on a 1,023 m³/day permit.
The works has headroom — so spills here point to another problem, often on that branch of the network (a blockage, a failed pump or infiltration).
On our estimate the works has spare capacity for about ~5,900 more people before it reaches its permitted flow.
Its permit
What the environmental permit sets for this overflow — and where the public record is silent, which is itself the finding.
- Pass-forward flow
- 1,023 m³/day (works DWF)
- Spill frequency limit
- None set
- Monitoring tier
- Not published
- Assessment trigger
- Not crossed (threshold 30/year)
Is anyone acting on this?
Nothing on record.
A flagged problem with no active measure against it. That is a gap in the public record.
What you can do about this one
Ask for the data
Under the Environmental Information Regulations, Blackbrook North, Princetown's telemetry, the works' flow-to-full-treatment setting, and any spill investigations are emissions information — they cannot be withheld on commercial-confidentiality grounds. A written request is the fastest lever.
Get it into the next programme
Investigations that will shape the 2030–35 environment programme must complete by this date. Putting this overflow on the record now — to South West Water and the Environment Agency — is what gets it considered.
Put it in the drainage plan
South West Water's draft Drainage & Wastewater Management Plan goes to a twelve-week consultation. A named overflow with evidence behind it is far harder to leave out.
The record since 2020
0 dry spills and 18 pre-STW spills since 2020. Pick a year to see its events below.
2026: 21 spills · 28 discharge events
Counted spills — the EA's 12/24-hour block method, the basis of the 10-a-year cap. Published annual return where available, computed the same way for the current year. Two ways to count →
Dry spills, every year
0 dry spills since 2020 · showing up to 12
No dry spills on record for this overflow since 2020.
Spilled before its works
18 events since 2020 · started while Princetown STW stayed shut
Spills by month — 2026 to date
Dry Wet weatherEvery spill in 2026, most recent first
Each event checked against the nearest rain gauge and against the treatment works’ own overflow. Open any row for its evidence dossier.
Excluded from the counts, classification and flags above — too short to weigh against rainfall, and often an operational blip rather than a genuine discharge. Listed here for completeness. How we know.