Environment Agency monitoring station
Marsh Lock
River Thames · Harpsden · Cherwell Thame and Wye catchment
EA station reference
2495TH
Live measurement feed
Water level over the last seven days
Readings show measured change at this instrument. A station reading is not a flood warning and, without an official threshold, does not prove that the river is safe or dangerous.
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Station location
Blue point = monitoring instrument, not a reported flood.
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About this station
- Monitors
- River Thames
- Catchment
- Cherwell Thame and Wye
- Nearest named place
- Harpsden
- EA opening date
- 1 January 1995
- Coordinates
- 51.52878, -0.88570
Nearby designated monitoring areas
Directory areas whose reference point is within approximately 10 km. Proximity does not mean this station controls that area or that a warning is active.
- Communities at risk of groundwater flooding including Turville, Skirmett, Stonor, Middle and Lower Assendon and parts of HenleyDesignated alert area · EA ref 061FAG23HenAssen
- River Thames from Henley down to Medmenham including Remenham and Mill EndDesignated warning area · EA ref 061FWF23HenMed
- River Thames for Henley, Remenham and Medmenham; including Middle and Lower Assendon on the Assendon Stream, and Skirmett and Hambleden on the Hambledon BrookDesignated alert area · EA ref 061WAF23HenMed
- Lower River Loddon at the River Thames confluence including Twyford, Charvil and Wargrave including Loddon DriveDesignated alert area · EA ref 061WAF24Twyford
- River Thames for Shiplake, Lower Shiplake, Wargrave including Loddon Drive, and Thames Drive, CharvilDesignated alert area · EA ref 061WAF23ShipWar
- River Thames at Reading and Caversham including the Portman Road and Richfield Avenue industrial estates, Caversham Road area of Reading and the Lower Caversham areaDesignated warning area · EA ref 061FWF23ReadCav
- River Thames from Mapledurham to Sonning, including Mapledurham, Reading, Caversham, Playhatch and SonningDesignated alert area · EA ref 061WAF23RdngSonn
- Lower River Loddon including Swallowfield, Arborfield, Shinfield, Barkham, Lower Earley, Sindlesham, Winnersh, Woodley, Hurst and Waltham St LawrenceDesignated alert area · EA ref 061WAF24LLoddon
- River Loddon at Winnersh and Woodley including Whistley Green, BerkshireDesignated warning area · EA ref 061FWF24Winnersh
- River Loddon at Twyford, Charvil and Wargrave including Loddon Drive, BerkshireDesignated warning area · EA ref 061FWF24Twyford
Nearby monitoring stations
Use nearby instruments for context, but do not compare absolute station-datum values as if they shared the same baseline.
Source and limits: station directory and readings from the Environment Agency under the Open Government Licence v3.0. API readings can be delayed or unavailable. For warnings and emergency advice, use the official GOV.UK flood service.