Environment Agency directory · East of England

Flood warnings and river levels in Hertfordshire

Current warnings are checked live. Monitoring areas, stations and watercourses below are directory records and may be listed even when no warning is in force.

Designated areas
88
Level stations
56
Named watercourses
39
Directory snapshot
6 Aug 2026, 01:13

Live Environment Agency status

Current flood warnings in Hertfordshire

Directory metadata refreshed 6 Aug 2026, 01:13 (UK time). Warning status is requested separately from the EA feed.

Permanent EA coverage

Designated monitoring areas in Hertfordshire

These are predefined places where the Environment Agency can issue a Flood Warning or Flood Alert. The category describes how EA organises the area; it does not show whether an alert is active now. Similar names can refer to different official stretches of the same river.

Official area nameWatercourse / coastEA area category
River Thames at Thames Ditton Island including Boyle Farm Island

EA ref 061FWB23DitIslnd

River ThamesDesignated warning area

Coverage type—not a current warning

River Thames at Thames Ditton Island including Boyle Farm Island

EA ref 061WAB23DitIslnd

River ThamesDesignated alert area

Coverage type—not a current warning

River Thames from Shepperton to West and East Molesey including Hamm Court, Walton-on-Thames and Sunbury

EA ref 061WAF23Shepprtn

River ThamesDesignated alert area

Coverage type—not a current warning

River Ivel from Langford to Blunham, including the rivers Purwell, Hiz, Flit and Hit

EA ref 052WAFIVEL

River IvelDesignated alert area

Coverage type—not a current warning

Trinity Marsh Ditch at Waltham Cross

EA ref 062FWF53Trinity

Trinity Marsh Ditch, Small River LeeDesignated warning area

Coverage type—not a current warning

The Radlett Brook at Radlett

EA ref 062FWF28Radlett

Radlett BrookDesignated warning area

Coverage type—not a current warning

The Upper River Colne and Radlett Brook at Colney Heath, London Colney, Borehamwood and Radlett

EA ref 062WAF28UpColne

River ColneDesignated alert area

Coverage type—not a current warning

The River Crane at Hillingdon, Southall, Cranford, Feltham and Twickenham

EA ref 062WAF36FluCrane

River CraneDesignated alert area

Coverage type—not a current warning

River Lee at Luton, Harpenden including Wheathampstead and East Hyde

EA ref 062WAF46UpperLee

River LeeDesignated alert area

Coverage type—not a current warning

Beverley Brook at Barnes, London Boroughs of Richmond upon Thames and Wandsworth

EA ref 064FWB40Barnes

Beverley BrookDesignated warning area

Coverage type—not a current warning

Beverley Brook area, including the Pyl Brook, in the London Boroughs of Merton, Sutton, Kingston upon Thames, Richmond upon Thames and Wandsworth

EA ref 064WAF40BevBrook

Beverley Brook, Pyl Brook, East Pyl BrookDesignated alert area

Coverage type—not a current warning

River Thames from the River Brent to the River Crane including East Isleworth and Syon Park

EA ref 063FWT23Islewrth

River ThamesDesignated warning area

Coverage type—not a current warning

Showing 12 of 88 matching areas

River-level monitoring

Stations and readings in Hertfordshire

Blue points are monitoring instruments—not flood incidents. Open a station for recent readings, time checked and nearby context.

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Blue point = monitoring stationMarker colour does not represent flood risk or water level

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Directory index

Watercourses associated with Hertfordshire

Rivers, streams, drains and coastal waters named in EA area or station records. Inclusion does not mean the watercourse is currently high or flooding.

  • Ash
  • Beane
  • Beverley Brook
  • Borehamwood Brook
  • Dane End Tributary
  • East Pyl Brook
  • Groundwater
  • Hogsmill
  • Hogsmill River
  • Mimmshall Brook
  • Mimram
  • Pyl Brook
  • Quin
  • Radlett Brook
  • Rags Brook
  • Rib
  • River Ash
  • River Beane
  • River Bulbourne
  • River Chess
  • River Colne
  • River Crane
  • River Gade
  • River Ivel

Check property-level risk before buying or insuring

Our directory lists 88 Environment Agency warning and alert areas associated with Hertfordshire. The count does not determine the risk to a specific address. Use the postcode checker and official long-term flood-risk service, then confirm cover with your insurer or a qualified professional where necessary.

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