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4.37

Trowlock Island

Thames
Thames from Hurley to Teddington catchment • Trowlock Island • Greater London • ID: 3404TH • Level
(23m ago) • 4 readings/hr • 174 views

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⤴ Unusual rise — FloodRadar+Top 1% rise rate for this gauge.
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Current Level
4.368 mAOD
▬ Steady
24h Max
4.371 mAOD
24h Min
4.333 mAOD
Typical Range
4.42 - 5.00
mAOD
Highest Recorded
5.58 mAOD
EA official record
5.58 in our data (since Aug 2004)
🚽 Sewage overflows nearby

Recent Water Levels

🌍 floodradar.co.uk
1 day

Recent Readings

Steady over 5h
08 Oct 21:00 ▬ steady 4.368 mAOD
08 Oct 20:45 ▬ steady 4.368 mAOD
08 Oct 20:30 ▬ steady 4.368 mAOD
08 Oct 20:15 ▬ steady 4.369 mAOD
08 Oct 20:00 ▬ steady 4.369 mAOD
08 Oct 19:45 ▬ steady 4.369 mAOD
08 Oct 19:30 ▬ steady 4.369 mAOD
08 Oct 19:15 ▬ steady 4.369 mAOD
08 Oct 19:00 ▼ -0.1 cm 4.369 mAOD
08 Oct 18:45 ▬ steady 4.370 mAOD
08 Oct 18:30 ▬ steady 4.370 mAOD
08 Oct 18:15 ▬ steady 4.370 mAOD
08 Oct 18:00 ▬ steady 4.370 mAOD
08 Oct 17:45 ▼ -0.1 cm 4.370 mAOD
08 Oct 17:30 ▲ +0.1 cm 4.371 mAOD
08 Oct 17:15 ▼ -0.1 cm 4.370 mAOD
08 Oct 17:00 ▬ steady 4.371 mAOD
08 Oct 16:45 ▲ +0.1 cm 4.371 mAOD
08 Oct 16:30 ▬ steady 4.370 mAOD
08 Oct 16:15 4.370 mAOD

Station Details

Technical details: references, datum, range, flow archive
  • Station Reference: 3404TH
  • RLOI id: 7269 (the EA's check-for-flooding station id)
  • EA Gauge ID: 3404TH-level-stage-i-15_min-mAOD
  • Parameter: Level
  • Unit: mAOD
  • Typical rise rate: 2 cm/hr (p95 sustained over 90 days)
  • Typical data delay: ~22 min (measured reading→publication lag)
  • Tidal: No
  • Lock / structure: No
  • Catchment Area: Thames from Hurley to Teddington
  • Typical Range: 4.420 – 5.000 mAOD
  • EA Cross-check: 4.37 mAOD (EA at 8 Oct 20:45)

Geographic coordinates may reflect the access point for the gauge, and not the precise location in the watercourse that it is taking readings from.

Nearby Stations

Gauges connected to this river, and others nearby. A distance “by river” follows the river on the map; any other is in a straight line.

Connected upstream

Connected downstream

Same river system, separate branch

Distances by river: OS Open Rivers. Contains OS data © Crown copyright and database rights 2026.

💧 Storm overflows upstream of this gauge

Storm overflows whose water reaches this gauge on the mapped river network, nearest first by distance along the river. The status is each water company's monitor: it says whether an overflow is discharging, not how much or what it contains.

159 storm overflows are traced upstream of this gauge, the nearest 1.3 km away along the river. 0 report discharging now, 152 report not discharging, and for 7 the monitor is offline or has not reported, so their status is not known.

💧
Thames Water · into Thames · 1.3 km upstream along the river
0 spills · 0 hours in 2025
Not discharging now · last
💧
Thames Water · into Hogsmill River · 2.1 km upstream along the river
2 spills · 2 hours in 2025
Not discharging now · last
💧
Thames Water · into River Thames · 2.9 km upstream along the river
2 spills · 3 hours in 2025
Not discharging now · last
💧
Thames Water · into Hogsmill River · 3.5 km upstream along the river
14 spills · 139 hours in 2025
Not discharging now · last
💧
Thames Water · into River Ember And Mole · 9.8 km upstream along the river
19 spills · 239 hours in 2025
Not discharging now · last
💧
Thames Water · into Hogsmill · 10.2 km upstream along the river
4 spills · 13 hours in 2025
Not discharging now · last
💧
Thames Water · into Mole · 19.2 km upstream along the river
24 spills · 268 hours in 2025
Not discharging now · last
💧
Thames Water · into River Wey · 21.3 km upstream along the river
28 spills · 426 hours in 2025
Not discharging now · last

151 more further upstream, up to 240.6 km away along the river.

Nearby, connection not known

Within 6 km in a straight line, but the river map cannot say whether their water passes this gauge.

💧
Thames Water · into Tidal Thames · 3.3 km away in a straight line · discharges to the sea, an estuary or tidal water
0 spills · 0 hours in 2025
No live feed for this overflow
💧
Thames Water · into River Thames · 3.6 km away in a straight line · discharges into a tidal reach, where the water moves both ways
8 spills · 18 hours in 2024
No live feed for this overflow
💧
Thames Water · into N/A · 4.0 km away in a straight line · discharges into a tidal reach, where the water moves both ways
4 spills · 5 hours in 2025
Not discharging now · last
💧
Thames Water · into River Thames Tidal · 4.8 km away in a straight line · discharges to the sea, an estuary or tidal water
17 spills · 203 hours in 2025
Not discharging now · last
💧
Thames Water · into Old Pyl Ditch · 5.5 km away in a straight line · no mapped watercourse close enough to be sure
1 spill · 1 hours in 2025
Not discharging now · last

3 other overflows within 6 km are downstream of this gauge or on another branch of the river network, so they are not listed.

These are the water companies' monitor statuses; a spill does not by itself explain a change in the gauge level. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels. Explore the sewage map →

Contains OS data © Crown copyright and database rights 2026.

Rainfall & Weather

Loading rainfall and weather data...

How often this river runs high

In a typical year this gauge reaches its typical high of 5.00 m on about 16 days. This year so far: 17 days.

2026 17 days so far
2025 14 days
2024 51 days
2023 16 days
2022 9 days
2021 12 days
2020 18 days
2019 16 days
2018 9 days
2017 0 days

Counted from each day's highest reading. Days with missing or implausible readings are left out.

Flood history near this gauge

Official Environment Agency warnings issued since 2008 for the 38 flood areas linked to this gauge (nearest 0.2 km away).

42flood warnings 1269flood alerts

Most recent flood warning: 6 Jan 2024 — River Thames at Sunbury

Year by year
YearWarningsAlerts
2026 0 102
2025 0 76
2024 4 148
2023 0 86
2022 0 70
2021 0 92
2020 1 114
2019 1 81
2018 0 79
2017 0 42
2016 0 88
2015 0 57
2014 26 84
2013 7 75
2012 3 52
2011 0 14
2010 0 2
2009 0 3
2008 0 4

Warnings apply to a whole flood area, not necessarily this exact spot. Years before 2006 aren't covered by the EA's historic record. See also the Trowlock Island flood history.

Flood areas linked to this gauge

Flood warnings and alerts are issued for whole areas. These are the 38 areas linked to this gauge, nearest first.

Show 30 more

Frequently asked questions

Is the River Thames at Trowlock Island flooding today?

The current level is 4.37m, which is below the typical range. Flooding is very unlikely at this level.

Is the river level rising or falling at Trowlock Island?

Based on the most recent readings, the level is currently steady. The chart above shows the last 12 hours of measurements by default (up to 7 days), updated roughly every 15 minutes.

What is a normal level for the River Thames at Trowlock Island?

The typical range at this station is 4.42m to 5.00m, based on Environment Agency historical data. Levels above 5.00m are higher than usually seen and may indicate a flood risk.

How often is this river level data updated?

Readings are supplied by the Environment Agency gauge. FloodRadar checks for updates roughly every 15 minutes; the timestamp above shows how recent the latest available reading is.

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📮 Flood risk by postcode near this gauge

Postcodes within 5 km with properties in the Environment Agency’s rivers-and-sea flood-risk bands:

Check any UK postcode’s flood risk →

🏠 Buying or renting around here? Get the Property Flood-Risk Report for any English postcode — official risk band, recorded floods, warning history, river behaviour and nearby storm overflows. £19 one-off. Learn more →