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Home › Rivers › River Allen

River Allen water levels

Live levels from 4 monitoring stations across Cornwall, Dorset, updated every 15 minutes.

4stations
0above typical high
3catchments
⚠️ Several distinct UK rivers share the name “River Allen” — sections below are grouped by catchment.

Gauges

River Allen — Dorset Stour

2 stations in this catchment

StationTownLevel nowStatusTrend
Loverley FarmMoor Crichel0.43 mASD 30m agoLow—
11.4 km by river
Walford MillWimborne Minster0.08 mASD 30m agoLow—

River Allen — Fal and St Austell Streams

1 station in this catchment

StationTownLevel nowStatusTrend
Idless Damstructureplace estimatedIdless0.02 mASD 45m agoLow—

River Allen — North Cornwall

1 station in this catchment

StationTownLevel nowStatusTrend
Penvoseplace estimatedSt Kew Highway0.05 m 30m agoLow—

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 the Allen above one of its gauges, from the source down. The river map knows where gauges are, not every stream, so a tributary without a gauge is not listed here.

River Allen — Dorset Stour

No gauged tributary joins the Allen above Walford Mill on the river map. Streams without a gauge are not counted here.

Where the Allen goes

Below Walford Mill, its water next reaches Wimborne, a gauge on River Stour, 3.0 km by river downstream.

River Allen — Fal and St Austell Streams

No gauged tributary joins the Allen above Idless Dam on the river map. Streams without a gauge are not counted here.

Where the Allen goes

Below Idless Dam, its water next reaches Truro Harbour, a gauge on Truro River, 4.3 km by river downstream.

River Allen — North Cornwall

No gauged tributary joins the Allen above Penvose on the river map. Streams without a gauge are not counted here.

Where the Allen goes

No gauge below Penvose is known on the river map.

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.

Storm overflows upstream

River Allen — Dorset Stour

None of the storm overflows FloodRadar holds is traced upstream of Walford Mill 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 the Allen’s gauges in a straight line, but the river map cannot say whether their water reaches it.

  • Brook Road Pumping Station Not discharging
    Wessex Water · into Tributary Of The River Stour · 1.7 km from Walford Mill in a straight line · no mapped watercourse close enough to be sure · 2025: 2 spills, 6.5 h
  • Pilford Heath Pumping Station Monitor offline
    Wessex Water · into Trib Of Uddens Water (S) · 2.8 km from Walford Mill in a straight line · its watercourse is not on the river map · 2025: 14 spills, 17 h

5 other overflows within 3 km of these gauges are placed below the Allen’s lowest gauge or on another river, so not listed.

River Allen — Fal and St Austell Streams

None of the storm overflows FloodRadar holds is traced upstream of Idless Dam 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 the Allen’s gauges in a straight line, but the river map cannot say whether their water reaches it.

  • Old Bridge Street Car Park CSO Not discharging shellfish water
    South West Water · into River Allen · 2.4 km from Idless Dam in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 18 spills, 18 h
  • St Clement's Hill CSO Not discharging shellfish water
    South West Water · into River Allen Via Sws(Estuarine) · 2.5 km from Idless Dam in a straight line · discharges to the sea, an estuary or tidal water · 2025: 4 spills, 1.5 h
  • Trelander Highway CSO Not discharging shellfish water
    South West Water · into River Allen(Estuarine) Via Sws · 2.5 km from Idless Dam in a straight line · discharges to the sea, an estuary or tidal water · 2025: 46 spills, 32 h
  • Fairmantle Street CSO Not discharging shellfish water
    South West Water · into River Kenwyn(E) · 2.7 km from Idless Dam in a straight line · discharges to the sea, an estuary or tidal water · 2025: 2 spills, 0.6 h

14 other overflows within 3 km of these gauges are placed below the Allen’s lowest gauge or on another river, so not listed.

River Allen — North Cornwall

2 storm overflows are traced upstream of Penvose, the Allen’s lowest gauge on the river map: on the Allen itself, on its gauged tributaries, and on smaller streams that join above there.

  • 0 report discharging now
  • 2 not discharging
  • 0 offline or silent: 0 monitor offline, 0 status unknown, 0 no live feed

Official figures for 2025, for the overflows traced upstream of Penvose: 159 spills over 2,911 hours in total, across all 2.

Each overflow is listed in the stretch above the first gauge its water reaches, from the source down, as on the Gauges tab. A stretch of the Allen includes the smaller streams that join it there.

Above Penvose, the Allen’s highest gauge2 overflows

Near these gauges, connection not known

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

  • St Teath Wastewater Treatment Works Not discharging
    South West Water · into Trib Of River Allen · 2.9 km from Penvose in a straight line · no mapped watercourse close enough to be sure · 2025: 101 spills, 101 h

1 other overflow within 3 km of these gauges is placed below the Allen’s lowest gauge or on another river, so not listed.

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: © Wessex Water storm overflow activity data, licensed under CC BY 4.0. Live status: © South West 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.

River Allen — Dorset Stour

10 sampling points on the River Allen and the streams that join it above Walford Mill, and below it. 4 have a sample from the last 12 months; 5 have any sample banked. Listed from the source down, grouped by the next gauge each one's water reaches.

Above Loverley Farm River Allen 5 points, 3 with samples
Sampling pointWatercourse (map)Above the gaugeLast sampleLatest results (river water)
River Allen downstream of All HallowsRiver Allen5.7 km10 Jul 2026 · 3 months agopH 7.64
Allen at Bottlebush Lane - Wimborne St GilesRiver Allen5.7 km1 Dec 2023 · 2.9 years agoOxygen 91%Temp 9.3 °CpH 7.51Ammonia below 0.03 mg/l
River Allen downstream of Allenbrook Fish FarmRiver Allen3.1 kmLast sampled 9 May 2006, before the imported period
River Allen 150 m downstream of Allenbrook FFMRiver Allen3.0 km14 Sep 2026 · 24 days agoOxygen 93.6%Temp 16.1 °CpH 7.94Ammonia below 0.03 mg/l
River Allen at Stanbridge MillRiver Allen0.9 kmLast sampled 13 Mar 2014, before the imported period
Above Walford Mill River Allen 4 points, 2 with samples
Sampling pointWatercourse (map)Above the gaugeLast sampleLatest results (river water)
River Allen at NewtownRiver Allen9.1 km1 Sep 2026 · 37 days agoOxygen 84.1%Temp 14.2 °CpH 7.88Ammonia below 0.03 mg/l
River Allen at WitchamptonRiver Allen7.7 kmLast sampled 4 Apr 2000, before the imported period
River Allen at Hinton ParvaRiver Allen5.6 kmLast sampled 2 Feb 2017, before the imported period
River Allen at High Hall (Fitches Bridge)River Allen2.8 km14 Sep 2026 · 24 days agoOxygen 94.6% Sep 2026Temp 16.5 °CpH 8.06 Sep 2026Ammonia below 0.03 mg/l
Below Walford Mill 1 point, 0 with samples
Sampling pointWatercourse (map)Below the gaugeLast sampleLatest results (river water)
Allen WalsfordRiver Allen0.2 kmLast sampled 1 Mar 2017, before the imported period

River Allen — Fal and St Austell Streams

3 sampling points on the River Allen and the streams that join it above Idless Dam, 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 Idless Dam River Allen 1 point, 0 with samples
Sampling pointWatercourse (map)Above the gaugeLast sampleLatest results (river water)
River Allen at Ladys WoodRiver Allen0.3 kmLast sampled 1 Mar 2023, before the imported period
Below Idless Dam 2 points, 1 with samples
Sampling pointWatercourse (map)Below the gaugeLast sampleLatest results (river water)
River Allen at Idless BridgeRiver Allen0.3 km18 Sep 2026 · 20 days agoOxygen 98%Temp 14.8 °CpH 7.66Ammonia below 0.03 mg/l
River Allen at Moresk Laundry BridgeRiver Allen2.3 kmLast sampled 9 Mar 2023, before the imported period

River Allen — North Cornwall

5 sampling points on the River Allen and the streams that join it above Penvose, and below it. 2 have a sample from the last 12 months; 3 have any sample banked. Listed from the source down, grouped by the next gauge each one's water reaches.

Above Penvose River Allen 3 points, 2 with samples
Sampling pointWatercourse (map)Above the gaugeLast sampleLatest results (river water)
River Allen at Treforda Bridgeunnamed stream5.3 kmLast sampled 10 Oct 2013, before the imported period
River Allen at Knightsmill BridgeRiver Allen4.0 km19 Mar 2025 · 19 months agoOxygen 98.3%Temp 9.2 °CpH 7.68Ammonia below 0.03 mg/l
River Allen at TrevillickRiver Allen2.3 km4 Feb 2026 · 8 months agoOxygen 99%Temp 9.7 °CpH 7.8Ammonia 0.02 mg/l
Below Penvose 2 points, 1 with samples
Sampling pointWatercourse (map)Below the gaugeLast sampleLatest results (river water)
River Allen at Kellygreen BridgeRiver Allen2.3 kmLast sampled 13 Jul 2018, before the imported period
River Allen at Dinhams BridgeRiver Allen5.2 km23 Sep 2026 · 15 days agoOxygen 100.7%Temp 16 °CpH 7.98Ammonia below 0.03 mg/l

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.

Wave tracker for this river → Cornwall rivers → Dorset rivers → All UK rivers