River Thames conditions - advice for boaters

Page Last Updated: 15 May 2021 23:54   

Thames Map Thumbnail

Welcome to the Environment Agency's online River Thames conditions update service which displays our current advice to river users. We display warning boards at our locks to inform river users of conditions that may make navigating difficult and dangerous.

This page shows our current advice for each reach of the river between Cricklade and Teddington. We will update this information regularly when warning boards are being displayed at locks and as river conditions change.

Lechlade to Oxford Back to Map

ReachCurrent conditions
Upstream of St John's LockNo Stream Warnings
St John's Lock to Buscot LockNo Stream Warnings
Buscot Lock to Grafton LockNo Stream Warnings
Grafton Lock to Radcot LockNo Stream Warnings
Radcot Lock to Rushey LockCaution stream increasing
Rushey Lock to Shifford LockCaution stream increasing
Shifford Lock to Northmoor LockCaution stream increasing
Northmoor Lock to Pinkhill LockCaution stream increasing
Pinkhill Lock to Eynsham LockCaution stream increasing
Eynsham Lock to King's LockCaution stream increasing
King's Lock to Godstow LockCaution stream increasing
Godstow Lock to Osney LockCaution strong stream
Osney Lock to Iffley LockNo Stream Warnings

Oxford to Henley Back to Map

ReachCurrent conditions
Iffley Lock to Sandford LockCaution stream increasing
Sandford Lock to Abingdon LockCaution stream increasing
Abingdon Lock to Culham LockCaution stream increasing
Culham Lock to Clifton LockCaution strong stream
Clifton Lock to Day's LockCaution stream increasing
Day's Lock to Benson LockCaution stream increasing
Benson Lock to Cleeve LockCaution stream increasing
Cleeve Lock to Goring LockCaution stream increasing
Goring Lock to Whitchurch LockCaution stream increasing
Whitchurch Lock to Mapledurham LockCaution stream increasing
Mapledurham Lock to Caversham LockCaution stream increasing
Upstream of Blake's LockNo Stream Warnings
Caversham Lock to Sonning LockCaution strong stream
Sonning Lock to Shiplake LockCaution stream increasing
Shiplake Lock to Marsh LockCaution stream decreasing
Marsh Lock to Hambleden LockCaution stream decreasing

Henley to Teddington Back to Map

ReachCurrent conditions
Hambleden Lock to Hurley LockCaution stream increasing
Hurley Lock to Temple LockCaution stream increasing
Temple Lock to Marlow LockCaution stream increasing
Marlow Lock to Cookham LockCaution stream increasing
Cookham Lock to Boulters LockCaution stream increasing
Boulters Lock to Bray LockCaution stream increasing
Bray Lock to Boveney LockCaution stream increasing
Boveney Lock to Romney LockNo Stream Warnings
Romney Lock to Old Windsor LockNo Stream Warnings
Old Windsor Lock to Bell Weir LockNo Stream Warnings
Bell Weir Lock to Penton Hook LockNo Stream Warnings
Penton Hook Lock to Chertsey LockNo Stream Warnings
Chertsey Lock to Shepperton LockNo Stream Warnings
Shepperton Lock to Sunbury LockCaution stream increasing
Sunbury Lock to Molesey LockNo Stream Warnings
Molesey Lock to Teddington LockNo Stream Warnings

Information for boaters

Coronavirus information

Please find the latest guidance for all boaters on Environment Agency managed waterways here: https://www.gov.uk/government/publications/environment-agency-waterways-coronavirus-covid-19-update.

In line with the current government Covid-19 restrictions we are taking the following approach to operating all of our lock and weir sites on the River Thames:

We aim to offer assisted passage to our boating customers during the boating season from 1 April to 30 September. We will also provide assisted passage during the Easter bank holiday weekend and spring and autumn half terms where these fall outside the season. Each lock will be manned by a resident, relief or seasonal Lock Keeper and/or volunteers, as appropriate and, wherever possible, to provide cover for staff breaks, weir work and maintenance. There may be occasions when we are unable to achieve this due to circumstances outside of our control such as staff illness.

Out of season between the 1 October and 31 March assisted passage may be available but cannot be guaranteed

Lock keepers’ hours of duty

  • July and August: 9am to 6:30pm
  • May, June and September: 9am to 6pm
  • April and October: 9am to 5pm
  • November to March: 9:15am to 4pm

One hour lunch break taken between 1pm and 2pm when cover unavailable.

Public power to be provided at all locks where available when assisted passage is not being offered by a Lock Keeper or volunteer, unless we are unable to do so due to circumstances outside of our control such as power outage or breakdown.

All of our sites accept card payments only. 

Teddington Lock also has special arrangements in place. You can find more detail on our River Thames restrictions and closures page.

From 13 April until 17 May 2021

  • Passage through Teddington Lock will be available from 6am to 10pm. Tidal transits and general assisted passage will be available between these times.
  • Visiting licences will be available at the lock. Please follow social distancing guidance at the site when purchasing.
  • As the self-service facility is not possible at Teddington, transit will not be possible through the night and from 10pm until 6am, the lock will be closed to traffic.

From 18 May

  • Full 24 hour service will resume including purchasing of licences and journey advice by calling 020 8940 8723. 

The levels of service will be reviewed regularly. Our staffing levels are currently reduced as a result of coronavirus.

Service announcements:

Some of our services are restricted due to the impact of the coronavirus (COVID-19) emergency. Go to locks and facilities for boaters for more detail.


  • Culham Lock is open and operational. Please be careful when entering the Lock site and do not enter the fenced area.
  • Mapledurham Lock sewage pump-out is unavailable.
  • Iffley Lock - Hand wind only out of hours due to a fault with the public power.
  • Cookham Lock electric charging point at the short stay moorings is unavailable. The next electric charging points are upstream Shiplake. 
  • Old Windsor electric charging point is currently unavailable.



Navigation Markers:


  • When travelling upstream keep red obstruction marker buoys on your left, and green buoys on your right.
  • When travelling downstream, keep red buoys on your right, and green buoys on your left.
  • Single yellow marker buoys can be passed on either side.


In all cases, pass well clear of marker buoys, and take care. You should also be careful in the margins of the river, and around bends, where river and weather conditions have resulted in tree debris collecting and some shallows forming.


Caution strong stream
We advise users of all boats not to navigate because the strong flows make it difficult and dangerous.
Caution stream increasing
We advise users of all unpowered boats not to navigate and users of powered boats to find a safe mooring. This is because river flows are likely to strengthen and red boards could be displayed very soon and without warning.
Caution stream decreasing
We advise users of all unpowered boats not to navigate and users of powered boats to navigate with caution.


This information is also available on Floodline. Call 0345 988 1188 and select option 1 for river information for boaters.


  • Contact Name: The Environment Agency

    Tel. 03708 506 506 (Monday to Friday, 8am to 5pm)

    E-mail: enquiries@environment-agency.gov.uk

  • Contact Name: Incident Hotline

    Tel. 0800 80 70 60 (24 hour service)

Related Links

Thames Locks MapThames Locks Map Names OverlayClick here to view current conditions for:
Lechlade to OxfordOxford to HenleyHenley to Teddington