River Tamar

Spill record· since 6 May 2026

In the last 30 days this overflow recorded 7h of discharge. Across South West Water's 1,345 monitored overflows the median was 0h. This site is in the top 25% by 30-day spill duration.

On the River Tamar· 32 other overflows

32 other overflows discharge into the River Tamar. Combined recorded discharge in the last 30 days: 380h.

• SBB00420inactive79h/30d
• SBB00523inactive73h/30d
• SBB00099inactive70h/30d
• SBB00540inactive43h/30d
• SBB00371inactive29h/30d
• SBB00944inactive17h/30d

All overflows recorded on this watercourse →

Recent spill events· last 30 days

• 2026-10-26 08:22 UTC4 min

  14.55 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-26 07:04 UTCend time not published

  10.34 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-24 18:57 UTC13 min

  42.21 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-24 17:16 UTCend time not published

  41.21 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-24 11:40 UTC4.8 h

  20.23 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-24 10:09 UTC7 min

  14.94 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-22 23:44 UTC9 min

  25.61 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-22 22:19 UTC11 min

  24.06 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-22 20:44 UTC12 min

  19.04 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-22 18:47 UTC10 min

  14.06 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-22 01:46 UTC4 min

  6.82 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-21 02:24 UTC29 min

  13.42 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-21 01:28 UTC7 min

  12.27 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

• 2026-10-15 22:02 UTC15 min

  5.7 mm rain in the 24 h before, gauge Gunnislake, 1.0 km

Rainfall comes from the nearest Environment Agency rain gauge within 10 km, using 15-minute readings rolled into hourly totals. Where a gauge is further away, or too many readings are missing, we say so rather than guess. Rain figures do not show whether a discharge was permitted; that is a matter for the regulator. How we keep the record.

The operator's own annual returns· 2024 to 2025

What the water company itself reported to the Environment Agency’s annual returns for this overflow, year by year. Hours are the total reported discharge duration; monitor working is the share of the year the event monitor was operating (a figure of 0% may mean no usable monitoring data rather than no spills). These figures are the operator's own reporting, not our measurement, and our live record above begins on 6 May 2026.

Source: Environment Agency, Event Duration Monitoring storm overflow annual returns, all years. Matched to this overflow by hub id.

How we keep the record.

Rain at the nearest gauge· 1.0 km away

The nearest Environment Agency rain gauge, Gunnislake, is 1.0 km from this overflow. It recorded 0.5 mm in the last 48 hours.

Rainfall comes from 15-minute Environment Agency readings rolled into hourly and daily totals; the 48-hour figure rests on 187 of 192 possible readings. The gauge is 1.0 km from this overflow, so it may not match the rain at the site itself, and the latest day may be incomplete. Rain figures do not show whether a discharge was permitted; that is a matter for the regulator. How we keep the record.

River level and flow nearby· 1.0 km away

Latest readings at the Environment Agency gauge "Gunnislake", on the River Tamar, which is 1.0 km from this overflow.

• River flow10.4332 h ago · falling over 24 h
• River level0.571 h ago · falling over 24 h

These are the Environment Agency's own gauge readings at the named station, shown for context. The station measures the river, not this overflow, and a reading does not show whether a discharge occurred or was permitted. Trend compares the latest reading with the one nearest 24 hours earlier; a change of 5% or less is shown as steady. How we keep the record.

Nearby water quality· 6 sampling points within 5 km

Take action

The record above is verifiable from public Environment Agency and water-company data. Three official accountability channels — pre-filled with the evidence on this page.

Subject: Storm overflow SBB00521 on the RIVER TAMAR VIA SWS: request for information

Dear South West Water,

I am writing about storm overflow SBB00521 on the RIVER TAMAR VIA SWS.

Environment Agency storm overflow monitoring data for overflow SBB00521 on the RIVER TAMAR VIA SWS (operator listed as South West Water) records 14 spill events starting between 4 October 2026 and 3 November 2026; the 12 with a published end time total 6.8 h. The most recent recorded event started on 26 October 2026 at 08:22 UTC.

As of 3 November 2026 at 06:50 UTC, the monitor does not report the overflow as spilling.

Further details from the public record:
- On the River Tamar, per the OS Open Rivers network (Ordnance Survey, Open Government Licence)
- Location: 50.52540, -4.21138
- Sources: Environment Agency National Storm Overflow Hub and Water Quality Archive (Open Government Licence v3.0), cross-referenced via River Truth (https://rivertruth.co.uk/overflow/25582)

These figures are taken from public monitoring data as published and may be revised by the publisher. They are not a finding that any permit condition has been breached.

[Add your personal context here, for example how you use this stretch of water.]

Please could you tell me:
1. Whether the monitoring record summarised above is accurate and complete
2. What caused the recorded spill events
3. What work, if any, is planned at this overflow, and on what timeline
4. What measures are in place to reduce spills from this overflow in future

[Delete if not applicable: I have copied the Environment Agency, Ofwat and my MP into this correspondence.]

Yours faithfully,
[Your name]
[Your address]
[Your customer reference if you are a South West Water customer]

Subject: Constituent query: storm overflow SBB00521 on the RIVER TAMAR VIA SWS

Dear [your MP, WriteToThem will fill this in],

I am writing as your constituent about public storm overflow monitoring data for our area.

Environment Agency storm overflow monitoring data for overflow SBB00521 on the RIVER TAMAR VIA SWS (operator listed as South West Water) records 14 spill events starting between 4 October 2026 and 3 November 2026; the 12 with a published end time total 6.8 h. The most recent recorded event started on 26 October 2026 at 08:22 UTC.

As of 3 November 2026 at 06:50 UTC, the monitor does not report the overflow as spilling.

Further details from the public record:
- On the River Tamar, per the OS Open Rivers network (Ordnance Survey, Open Government Licence)
- Location: 50.52540, -4.21138
- Sources: Environment Agency National Storm Overflow Hub and Water Quality Archive (Open Government Licence v3.0), cross-referenced via River Truth (https://rivertruth.co.uk/overflow/25582)

These figures are taken from public monitoring data as published and may be revised by the publisher. They are not a finding that any permit condition has been breached.

[Add your personal context here, for example how you and your family use this stretch of water.]

I would like to ask:
1. Whether you support strengthening the regulatory regime for storm overflows, and monitor coverage in particular
2. Whether you would raise the monitoring data for this overflow with the Secretary of State for Environment, Food and Rural Affairs, the Environment Agency or Ofwat

Yours sincerely,
[Your name]
[Your address (WriteToThem requires a postal address to verify your constituency)]