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0.06

Whitwell

Mimram
Mimram catchment • Whitwell • Hertfordshire • ID: 4730TH • Level
(21m ago) • 4 readings/hr • 135 views

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Current Level
0.061 mASD
▬ Steady
24h Max
0.063 mASD
24h Min
0.061 mASD
Typical Range
0.02 - 0.50
mASD
Highest Recorded
0.28 mASD
12 Feb 2001
Since Jan 1982
Current level is 22% of this
🚽 Sewage overflows nearby

Recent Water Levels

🌍 floodradar.co.uk
1 day

Recent Readings

Steady over 6h
23 Aug 23:30 ▬ steady 0.061 mASD
23 Aug 23:15 ▬ steady 0.061 mASD
23 Aug 23:00 ▬ steady 0.061 mASD
23 Aug 22:45 ▬ steady 0.061 mASD
23 Aug 21:30 ▬ steady 0.061 mASD
23 Aug 21:15 ▬ steady 0.061 mASD
23 Aug 21:00 ▬ steady 0.061 mASD
23 Aug 20:45 ▬ steady 0.061 mASD
23 Aug 20:30 ▬ steady 0.061 mASD
23 Aug 20:15 ▬ steady 0.061 mASD
23 Aug 20:00 ▬ steady 0.061 mASD
23 Aug 19:45 ▬ steady 0.061 mASD
23 Aug 19:30 ▬ steady 0.061 mASD
23 Aug 19:15 ▬ steady 0.061 mASD
23 Aug 19:00 ▬ steady 0.061 mASD
23 Aug 18:45 ▬ steady 0.061 mASD
23 Aug 18:30 ▬ steady 0.061 mASD
23 Aug 18:15 ▬ steady 0.061 mASD
23 Aug 18:00 ▬ steady 0.061 mASD
23 Aug 17:45 0.061 mASD

Rainfall & Weather

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Flood history near this gauge

Official Environment Agency warnings issued since 2009 for the 8 flood areas linked to this gauge (nearest 2.4 km away).

4flood warnings 25flood alerts

Most recent flood warning: 27 Sep 2024Ash Brook, Ippollitts Brook and River Purwell at Hitchin, Ashbrook, Little Wymondley and Graveley

Year by year
YearWarningsAlerts
2025 0 1
2024 2 8
2022 0 2
2021 1 3
2020 0 2
2016 0 1
2015 1 0
2014 0 4
2013 0 1
2012 0 1
2010 0 1
2009 0 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 Whitwell flood history.

Nearby Stations

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Station Details

  • Monitoring Station: Whitwell
  • Watercourse: River Mimram
  • Nearest Town: Whitwell
  • County: Hertfordshire
  • Coordinates: 51°52'37"N 0°16'53"W (51.876889, -0.281280)
  • Open in: Google Maps · Apple Maps (opens your maps app)
  • Date Opened: 1 Jan 1981
  • Status: Active
  • Station Type: River level station
  • Station Reference: 4730TH
  • EA Gauge ID: 4730TH-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: Mimram
  • Typical Range: 0.021 – 0.500 mASD
  • Drainage Area: 39 km² upstream of this gauge
  • Flow Data: Available (m³/s) via EA Hydrology
  • EA Cross-check: 0.06 mASD (EA at 23 Aug 23:15)
  • 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.

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
0.86
groundwater-fed — slow & steady
Avg Annual Rainfall
665 mm/yr
1991–2020 · +3% since 1941–70
Urban Extent
0.8%
largely rural
Highest Recorded Flow
0.467 m³/s
13 Oct 1993
Flow-Duration Curve
mean 0.0840.1890.0780.0145% (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 9%Grassland 23%Arable 65%Urban 2%
Arable 72% → 65% 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

The station is located in the upper Mimram catchment.

More detail

The catchment

A predominantly pervious (Chalk), rural catchment. Hydrological catchment divide is uncertain.

The station

Crump weir, 1.0m crest (rather insensitive) within wider section.

How it measures flow

All flows are contained and are modular.

Flow regime

Generally stable flow regime, sustained from Chalk springs. Low flows are occasionally augmented by pumping from local tube wells but overall runoff is significantly reduced by gw abstraction. U/s cress-beds can influence low flow pattern.

The flow record

Dry for over three months in late 1997.

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
Crump weir
Operating since
1970
Station datum
88.1 mAOD
Flow record
1970–2024 · 54 yrs · 100% complete
Hydrometric area
38
Measured by
Environment Agency

Frequently asked questions

Is the River Mimram at Whitwell flooding today?

The current level is 0.06m, which is within the typical range of 0.02 to 0.50m. Flooding is unlikely at this level.

Is the river level rising or falling at Whitwell?

Based on the most recent readings, the level is currently steady. The chart above shows the last 7 days of measurements, updated roughly every 15 minutes.

What is a normal level for the River Mimram at Whitwell?

The typical range at this station is 0.02m to 0.50m, based on Environment Agency historical data. Levels above 0.50m are higher than usually seen and may indicate a flood risk.

How often is this river level data updated?

Readings are taken by the Environment Agency gauge roughly every 15 minutes and FloodRadar refreshes its data continuously, so the level shown is normally less than an hour old.

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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, floods since 1946, warning history, river behaviour and nearby storm overflows. £19 one-off. Learn more →