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0.14

Colney Street

Ver
Colne (Upper) catchment • Colney Street • Hertfordshire • ID: 2819TH • Level
(22m ago) • 4 readings/hr • 164 views

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Current Level
0.142 mASD
▬ Steady
24h Max
0.145 mASD
24h Min
0.140 mASD
Typical Range
0.06 - 0.54
mASD
Highest Recorded
0.56 mASD
EA official record
0.56 in our data (since Jul 1986)
Current level is 25% of this
🚽 Sewage overflows nearby

Recent Water Levels

🌍 floodradar.co.uk
1 day

Recent Readings

Steady over 5h
08 Oct 16:45 ▬ steady 0.142 mASD
08 Oct 16:30 ▬ steady 0.142 mASD
08 Oct 16:15 ▬ steady 0.142 mASD
08 Oct 16:00 ▬ steady 0.142 mASD
08 Oct 15:45 ▬ steady 0.142 mASD
08 Oct 15:30 ▬ steady 0.142 mASD
08 Oct 15:15 ▬ steady 0.142 mASD
08 Oct 15:00 ▬ steady 0.142 mASD
08 Oct 14:45 ▬ steady 0.142 mASD
08 Oct 14:30 ▲ +0.1 cm 0.142 mASD
08 Oct 14:15 ▬ steady 0.141 mASD
08 Oct 14:00 ▬ steady 0.141 mASD
08 Oct 13:45 ▬ steady 0.141 mASD
08 Oct 13:30 ▬ steady 0.141 mASD
08 Oct 13:15 ▬ steady 0.140 mASD
08 Oct 13:00 ▬ steady 0.140 mASD
08 Oct 12:45 ▬ steady 0.140 mASD
08 Oct 12:15 ▬ steady 0.140 mASD
08 Oct 12:00 ▬ steady 0.140 mASD
08 Oct 11:45 0.141 mASD

Station Details

  • Monitoring Station: Colney Street
  • Watercourse: River Ver
  • Nearest Town: Colney Street
  • County: Hertfordshire
  • Coordinates: 51°42'17"N 0°20'10"W (51.704664, -0.336052)
  • Open in: Google Maps · Apple Maps (opens your maps app)
  • Date Opened: 1 Jan 1985
  • Status: Active
  • Station Type: River level station
Technical details: references, datum, range, flow archive
  • Station Reference: 2819TH
  • RLOI id: 7182 (the EA's check-for-flooding station id)
  • EA Gauge ID: 2819TH-level-stage-i-15_min-mASD
  • Parameter: Level
  • Unit: mASD
  • Typical rise rate: 0 cm/hr (p95 sustained over 90 days)
  • Typical data delay: ~22 min (measured reading→publication lag)
  • Tidal: No
  • Lock / structure: No
  • Catchment Area: Colne (Upper)
  • Typical Range: 0.064 – 0.539 mASD
  • Drainage Area: 132 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: 0.14 mASD (EA at 8 Oct 16:15)
  • 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

Nearby

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.

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

This gauge rarely reaches its typical high of 0.54 m: 0 days since 2017. This year so far: 0 days.

2026 0 days so far
2025 0 days
2024 0 days
2023 0 days
2022 0 days
2021 0 days
2020 0 days
2019 0 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 2009 for the 13 flood areas linked to this gauge (nearest 2.0 km away).

10flood warnings 146flood alerts

Most recent flood warning: 19 Jul 2025 — Radlett and Borehamwood Brooks at Borehamwood

Year by year
YearWarningsAlerts
2026 0 13
2025 1 7
2024 0 26
2023 0 11
2022 0 5
2021 2 13
2020 0 12
2019 0 6
2018 0 4
2017 0 5
2016 0 8
2015 0 6
2014 5 9
2013 0 6
2012 1 10
2011 0 1
2010 0 2
2009 1 2

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 Colney Street flood history.

Flood areas linked to this gauge

Flood warnings and alerts are issued for whole areas. These are the 13 areas linked to this gauge, nearest first.

Show 5 more

Catchment Character

🌊 Groundwater-fed Slow and steady — fed largely by groundwater, so levels change gradually, not in sudden spikes.

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
0.68
groundwater-fed — slow & steady
Avg Annual Rainfall
730 mm/yr
1991–2020 · +4% since 1941–70
Urban Extent
11%
partly urbanised
Median Annual Flood
1.23 m³/s
QMED — typical yearly peak flow
Highest Daily Mean Flow
2.97 m³/s
14 Feb 2001 · daily mean, not the instantaneous peak
Flow-Duration Curve
mean 0.4421.030.3710.0865% (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 7%Grassland 32%Arable 41%Urban 19%Other 1%
Arable 52% → 41% since 1990

Flow affected by: groundwater abstraction.

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

Most downstream gauging structure on the River Ver composed of a Compound Crump weir.

More detail

The catchment

Permeable Chalk catchment, with significant Drift cover. Mostly rural headwaters but with significant urban development in the lower valley. Topographical catchment area significantly exceeds the hydrological catchment.

The station

Compound Crump weir with 2 crests, each 2.44m broad. Superseded the original broad-crested weir in 1969 (plus a bypass channel).

How it measures flow

Theoretical crump weir formula used to calculate flow, evidence suggests weir rarely drowns or by-passed. Uncertainty in calibration gaugings influenced by the difficulty in finding a suitable gauging location. In March 2016, low cost baffles were installed to aid fish passage.

Flow regime

Relatively stable, spring-fed flow regime but artificial influences (sewage effluent returns especially) evident in low flow patterns. Changing groundwater abstraction pattern over time. Runoff diminished by large groundwater abstractions (including public water supply for Luton). These increased sharply from 1950, changing the character of the river, until a restoration programme (alleviation of low flow) was initiated in the early 1990s; abstractions much reduced by the late 1990s.

The flow record

The early flow data are of a lesser quality (pre-1969). Full period of record peak flow data reviewed and released in September 2019 (WINFAP Files v8).

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
Gauging structure
Operating since
1956
Station datum
62.3 mAOD
Flow record
1956–2024 · 68 yrs · 100% complete
Peak-flow record
since 1956
Hydrometric area
39
Measured by
Environment Agency

Frequently asked questions

Is the River Ver at Colney Street flooding today?

The current level is 0.14m, which is within the typical range of 0.06 to 0.54m. Flooding is unlikely at this level.

Is the river level rising or falling at Colney Street?

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 Ver at Colney Street?

The typical range at this station is 0.06m to 0.54m, based on Environment Agency historical data. Levels above 0.54m 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 →