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0.31

Addlestone

Addlestone Bourne
Bournes catchment • Addlestone • Surrey • ID: 2989TH • Level
(1h ago) • 4 readings/hr • 155 views

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Current Level
0.310 mASD
▬ Steady
24h Max
0.336 mASD
24h Min
0.302 mASD
Typical Range
0.31 - 0.90
mASD
Highest Recorded
1.98 mASD
EA official record
1.57 in our data (since Jan 1991)
Current level is 16% of this
Current Flow
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🚽 Sewage overflows nearby

Recent Water Levels

🌍 floodradar.co.uk
1 day

Recent Readings

Steady over 6h
08 Oct 01:30 ▲ +0.2 cm 0.310 mASD
08 Oct 01:15 ▬ steady 0.308 mASD
08 Oct 01:00 ▲ +0.2 cm 0.308 mASD
08 Oct 00:45 ▼ -0.1 cm 0.306 mASD
08 Oct 00:30 ▲ +0.1 cm 0.307 mASD
08 Oct 00:15 ▼ -0.1 cm 0.306 mASD
08 Oct 00:00 ▲ +0.1 cm 0.307 mASD
07 Oct 23:45 ▼ -0.1 cm 0.306 mASD
07 Oct 23:30 ▬ steady 0.307 mASD
07 Oct 22:30 ▼ -0.2 cm 0.307 mASD
07 Oct 22:15 ▲ +0.1 cm 0.309 mASD
07 Oct 22:00 ▬ steady 0.308 mASD
07 Oct 21:45 ▼ -0.2 cm 0.308 mASD
07 Oct 21:30 ▲ +0.1 cm 0.310 mASD
07 Oct 21:15 ▼ -0.1 cm 0.309 mASD
07 Oct 21:00 ▼ -0.1 cm 0.310 mASD
07 Oct 20:45 ▬ steady 0.311 mASD
07 Oct 20:30 ▲ +0.1 cm 0.311 mASD
07 Oct 20:15 ▼ -0.1 cm 0.310 mASD
07 Oct 20:00 0.311 mASD

Station Details

  • Monitoring Station: Addlestone
  • Watercourse: Addlestone Bourne
  • Nearest Town: Addlestone
  • County: Surrey
  • Coordinates: 51°22'27"N 0°28'43"W (51.374167, -0.478479)
  • Open in: Google Maps · Apple Maps (opens your maps app)
  • Date Opened: 1 Jan 1990
  • Status: Active
  • Station Type: River level station
Technical details: references, datum, range, flow archive
  • Station Reference: 2989TH
  • RLOI id: 7225 (the EA's check-for-flooding station id)
  • EA Gauge ID: 2989TH-level-stage-i-15_min-mASD
  • Parameter: Level
  • Unit: mASD
  • Typical rise rate: 1 cm/hr (p95 sustained over 90 days)
  • Typical data delay: ~22 min (measured reading→publication lag)
  • Tidal: No
  • Lock / structure: No
  • Catchment Area: Bournes
  • Typical Range: 0.313 – 0.900 mASD
  • Drainage Area: 90 km² upstream of this gauge
  • Flow Data: Daily mean flow (m³/s) to 6 Oct (2 days behind — the EA publishes each day's mean a day or two after it ends; unchecked, provisional) via EA Hydrology
  • EA Cross-check: 0.31 mASD (EA at 8 Oct 01:45)
  • Flow Archive: National River Flow Archive ↗

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

None of the storm overflows FloodRadar holds is traced upstream of this gauge on the mapped river network. That is not the same as none: the map leaves out many small streams and culverts, so an overflow it cannot place may still drain here, and not every company publishes every overflow. Those nearby are listed below.

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 Rive Ditch · 2.9 km away in a straight line · its water cannot be followed on the map
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 0.90 m on about 6 days. This year so far: 6 days.

2026 6 days so far
2025 12 days
2024 13 days
2023 9 days
2022 5 days
2021 3 days
2020 4 days
2019 4 days
2018 0 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 2013 for the 10 flood areas linked to this gauge (nearest 0.2 km away).

11flood warnings 37flood alerts

Most recent flood warning: 24 Feb 2025 — Hoe Stream at Woking

Year by year
YearWarningsAlerts
2026 0 2
2025 1 3
2024 3 7
2023 0 4
2022 0 5
2021 0 2
2020 2 1
2019 0 3
2018 0 3
2017 0 3
2016 1 0
2014 3 3
2013 1 1

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 Addlestone flood history.

Flood areas linked to this gauge

Flood warnings and alerts are issued for whole areas. These are the 10 areas linked to this gauge, nearest first.

Show 2 more

Catchment Character

🌊 Urban & flashy Heavily built-up — rain runs off hard surfaces fast, so levels can spike within hours of heavy rain.

Your catchment is all the land that drains rainfall into the river above this gauge. Its character — how steep, wet, wooded, urban or chalky that land is — decides how fast rain here turns into a rising river. A steep, bare or clay catchment is “flashy” (rises and falls quickly, floods easily); a flat, chalk or well-wooded one is slow and steady. The tiles below put numbers to that; the flow-duration curve reads left-to-right from the river’s typical high flows (Q5) down to its low flows (Q95) — a steep curve means a flashy river.

The physical character of the land that drains to this gauge, and how it shapes its flood response — from the National River Flow Archive (UKCEH).

Baseflow Index
0.57
mixed response
Avg Annual Rainfall
700 mm/yr
1991–2020 · +2% since 1941–70
Urban Extent
15%
heavily urbanised
Highest Daily Mean Flow
9.90 m³/s
7 Nov 2000 · daily mean, not the instantaneous peak
Flow-Duration Curve
mean 0.8322.090.6430.2855% (high)% of days exceeded95% (low)
Daily flow (m³/s) exceeded each % of the time — a steep curve is flashy, a flat one is steady. Q5 high · Q50 median · Q95 low.
Land Cover (2023)
Woodland 26%Grassland 37%Arable 1%Heath/scrub 11%Urban 26%
Urban 21% → 26% since 1990

Flow affected by: effluent returns.

Photos

Gauging-station photographs from the National River Flow Archive (UKCEH).

Photos © NRFA / UKCEH & the measuring authority — shown at web resolution. Full gallery on the NRFA ↗

About this gauge

Ultrasonic station with patchy early record.

More detail

The catchment

The geology is largely impermeable Bagshot Beds. Very mixed land use with woodland and heath plus significant urban development.

The station

Cross-path time-of-flight ultrasonic station installed in 2012/13. After becoming ultrasonic, a bund was added to promote head level at low flows. Prior to ultrasonic, this was a velocity area station - low level sharp-crested weir (rather insensitive with poor approach conditions).

How it measures flow

Control passes to road bridge at medium/high flows. Some confirmatory gaugings up to approx. 10 cumecs. Possible bypassing into R. Wey system (via canal) at very high flows. Rating change in Oct 1993 (earlier data may need reprocessing).

Flow regime

Responsive regime.

The flow record

Patchy early record (when no back-up recorder).

Descriptions from the National River Flow Archive (UKCEH). NRFA station record ↗

Gauge Details

How this gauging station is built and how long it has measured (NRFA / UKCEH).

Gauge type
Ultrasonic
Operating since
1991
Station datum
10.9 mAOD
Flow record
1991–2024 · 33 yrs · 94% complete
Hydrometric area
39
Measured by
Environment Agency

Frequently asked questions

Is the Addlestone Bourne at Addlestone flooding today?

The current level is 0.31m, which is below the typical range. Flooding is very unlikely at this level.

Is the river level rising or falling at Addlestone?

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 Addlestone Bourne at Addlestone?

The typical range at this station is 0.31m to 0.90m, based on Environment Agency historical data. Levels above 0.90m 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 →