Home › Rivers › Mill Bourne

Mill Bourne water levels

Live levels from 1 monitoring station across Surrey, updated every 15 minutes.

1stations
0above typical high

Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Millbourne BridgeChobham0.93 mASD 3h agoNormal

Stations are listed from source to mouth as the water flows, traced on the river map (OS Open Rivers) and the Environment Agency’s own links between its gauges. A distance “by river” is along the river, and is shown only where the map traces the path.

Contains OS data © Crown copyright and database rights 2026.

Gauged tributaries

Streams and rivers with a gauge whose water joins Mill Bourne above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.

1 gauged tributary, 1 gauge

Windle Brook

Joins Mill Bourne above Millbourne Bridge, its highest gauge, no more than 7.5 km by river above Millbourne Bridge.

Bagshot0.68 mASD 1h agoNormal

Its water passes every gauge on Mill Bourne, from Millbourne Bridge down.

Where Mill Bourne goes

Below Millbourne Bridge, its water next reaches Addlestone, a gauge on The Bourne, 12.8 km by river downstream.

Tributaries and where they join are traced on the river map (OS Open Rivers, edition 2026-04) and the Environment Agency’s links between its gauges. The map holds distances between gauges, not the junctions themselves, so a junction is placed between two gauges, and no further up than the tributary’s own lowest gauge. Contains OS data © Crown copyright and database rights 2026.

Streams without a gauge

Named streams on the river map that flow into Mill Bourne and have no gauge of their own. Each has a page with what is known about it: the next gauge downstream, and any storm overflows or water-sampling points placed on it.

  • Hale Bourne (joins about 880 m above Millbourne Bridge)

Storm overflows upstream

None of the storm overflows FloodRadar holds is traced upstream of Millbourne Bridge on the river map. 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.

Near these gauges, connection not known

Within 3 km of one of Mill Bourne’s gauges in a straight line, but the river map cannot say whether their water reaches it.

  • Chobham (Old) WwTW Not discharging
    Thames Water · into Bourne - South · 1.1 km from Millbourne Bridge in a straight line · no mapped watercourse close enough to be sure · 2025: 20 spills, 288 h

A status is the water company’s own monitor: it says whether an overflow is discharging, never how much or why, and a spill does not by itself explain a change in a river level. A status older than two hours is shown as unknown. Annual figures are the official returns: 12/24-hour spills for England and Wales, overflow events for Scotland (Scottish Water counts differently, so the two cannot be compared). “No data” means the monitor produced no usable data that year, not zero. Overflows are placed on OS Open Rivers (edition 2026-04), which leaves out many small channels: an overflow the map cannot place may still drain here. Contains OS data © Crown copyright and database rights 2026. Sewage in Britain’s rivers →

Live status: © Thames Water storm overflow activity data, licensed under CC BY 4.0. Annual figures for England: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence v3.0.

Water samples

Dated samples taken by the Environment Agency, not live readings. Results are published days to months after the sample is taken, and many points are sampled only a few times a year, or have not been sampled for years.

2 sampling points on the Mill Bourne and the streams that join it above Millbourne Bridge, and below it. 1 has a sample from the last 12 months; 1 has any sample banked. Listed from the source down, grouped by the next gauge each one's water reaches.

Above Millbourne Bridge Mill Bourne 1 point
Sampling pointWatercourse (map)Above the gaugeLast sampleLatest results (river water)
Hale Bourne at Halebourne Lane, ChobhamHale Bourne2.4 km18 Aug 2026 · 51 days agoOxygen 72.4%Temp 19.5 °CpH 7.52Ammonia below 0.03 mg/l
Below Millbourne Bridge 1 point, 0 with samples
Sampling pointWatercourse (map)Below the gaugeLast sampleLatest results (river water)
Upstream of Chobham MeadowsMill Bourne0.1 kmNo sample published 1 Oct 2023 – 7 Oct 2026

Distances are along the river to the gauge named. England's samples only.

FloodRadar does not grade these results: there is no overall score, and official river classifications are a separate dataset. A sample taken downstream of an overflow does not by itself show where anything in it came from. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.

Water samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.

Contains OS data © Crown copyright and database rights 2026.