Fal and St Austell Streams catchment
• Idless • Cornwall • ID: 48115 • Level
⚙ EA retired the upstream stage gauge (last upstream reading 2026-06-13); now showing the downstream level of the structure. Thresholds derived from downstream data.
(45m ago) • 4 readings/hr • 121 views
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You'll be notified when this gauge is rising more than 0.10 m/hr — a sign of rapidly increasing water levels.
You'll be notified when a new storm-overflow (sewage) discharge starts within ~3 km of this gauge, based on the water companies' near-real-time feeds.
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Current Level
0.039 mASD
▲ Rising slightly
24h Max
0.040 mASD
24h Min
0.015 mASD
Typical Range
0.05 - 1.10
mASD
Highest Recorded
1.25 mASD
EA official record
A 3.91 reading (16 Mar 2013) sits in our unverified raw history and is not treated as the record
Current level is 3% of this
🚽Sewage overflows nearby
Recent Water Levels
🌍 floodradar.co.uk
1 day
EA forecast (official)
Flood predictions aren't generated for
lock / structure gauges —
their levels are driven by gate operation,
not by catchment rainfall, so the forecast models would have no skill here.
Downstream level
7 days
The level on the DOWNSTREAM side of this lock/weir structure — a separate EA
measure from the main (upstream) reading shown on the Current tab. Threshold bands
are computed from this gauge's own downstream history.
RLOI id: 3171 (the EA's check-for-flooding station id)
EA Gauge ID: 48115-level-downstage-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: ⚙ Yes — EA retired the upstream stage gauge (last upstream reading 2026-06-13); now showing the downstream level of the structure. Thresholds derived from downstream data.
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.
South West Water · into Tresillian River Estuary(E) · 4.8 km away in a straight line · discharges to the sea, an estuary or tidal water
55 spills · 716 hours in 2025
Not discharging now · last
3 more within 6 km whose connection is not known.
15 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 →
This gauge rarely reaches its typical high of 1.10 m:
0 days since 2017.
This year so far: 0 days.
20260 days so far
20250 days
20210 days patchy data
20200 days
20190 days
20180 days
20170 days
Counted from each day's highest reading. Days with missing or implausible readings are left out, so a year marked patchy may have run high more often than shown.
Flood history near this gauge
Official Environment Agency warnings issued since 2012 for the 12 flood
areas linked to this gauge (nearest 1.3 km away).
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 Idless flood history.
Flood areas linked to this gauge
Flood warnings and alerts are issued for whole areas. These are the 12 areas linked to this gauge, nearest first.
The current level is 0.04m, which is below the typical range. Flooding is very unlikely at this level.
Is the river level rising or falling at Idless Dam?
Based on the most recent readings, the level is currently rising slightly. 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 Allen at Idless Dam?
The typical range at this station is 0.05m to 1.10m, based on Environment Agency historical data. Levels above 1.10m 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:
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