Staying safe on higher river flow

This document provides information that may help you to make your own decisions when paddling on the Thames. Hampton Canoe Club does not suggest that it’s safe to paddle when the flow is high. Paddling has inherent risks, and you need to make your own decisions when to paddle, informed by the environment as well as your own skills and knowledge of your equipment.

Keep in mind that the majority of club coaches do not paddle on the Thames when red boards are out, and few (if any) coaching sessions will occur on red boards. In fact, most coaches will not coach on yellow boards either.

The Environment Agency puts out helpful information at each lock on the Thames, indicating whether there is a yellow caution (stream could be increasing or decreasing) or red caution (strong stream).  This same information is available on the Environment Agency river conditions site and is updated once a day (around 11am).

When on yellow boards the Environment Agency advises that users of unpowered boats do not navigate, and when on red boards they advise that no boats navigate.

Current conditions:

Boards	Walton flow rate (cumecs)	Approximate river speed	Comments
None	< 80	< 2 km/h	Moderate flow
Yellow	80 – 120	2-3 km/h	Fairly powerful flow with swirls and eddies
Red	> 120	3-7+ km/h	Powerful to extremely powerful flow:  potentially dangerous swirls and eddies

Note that these are approximate average speeds on the stretch of water between Molesey lock and Sunbury lock.  The actual water speed depends on the width of the river, and can be substantially faster in narrow areas, for example next to Platt’s Eyot and upstream of the Sunbury ferry crossing.

These water speeds can be deceptive.  Most people can walk at a pace that is faster than the river, even at strong flow. But consider that if you capsize in a 5 km/h current you will be swept 250 metres downstream during a 3 minute swim.  To deal with this, you need to be a strong swimmer, be comfortable to do a self rescue, or paddle with somebody who can help you with a deep water rescue.

Since flow rates increase after heavy rain, and we experience most of our heavy rain during the colder months, you need to consider that red boards are associated with colder water temperatures.

When you go paddling, there always is a risk of capsizing and the consequence of drowning if you can’t do a self-rescue or be rescued.

But in periods of strong flow, you need to take particular precautions to mitigate against entrapment or hypothermia in the event of capsize.

Risk	Description	Mitigation action
Capsize	Higher risk of capsize due to eddies and turbulence	Paddle a more stable boat than usual Pack a change of clothes in a dry bag and keep with you in the boat
Entrapment	Getting stuck between obstacles, including moored boats, trees and jetties.	Avoid areas with jetties and moored boats On yellow or red boards, paddle on the Surrey side of Platt’s. Avoid areas upstream of weirs and locks
Hypothermia	In colder water, your judgement may be impaired even after just a few minutes of submersion.	Wear appropriate clothing, especially if the water is colder than 16 degrees. Wear a wetsuit if the water is colder than 10 degrees Only paddle when the water is colder than 5 degrees when you’ve taken special precautions (typically during January and February)
Water pollution	During high flow there is an increased risk of Water companies discharging waste water into the Thames	Do not swallow the water Ensure you properly cover and disinfect any open wounds Wash your hands  (and equipment) after coming off the water

You can use this table as a rough guideline for water temperature:

Months	Average water temperature
Jan – Mar	Under 10 degrees, frequently below 5 degrees, especially Jan – Feb
Apr – Jun	10 – 15 degrees
Jul – Sep	Higher than 15 degrees, occasionally 20 degrees or more
Oct – Dec	Below 15 degrees, dropping below 10 degrees in November

Paddling on yellow boards is manageable for a fit and competent paddler, although going upstream can feel like hard work because you will be making slower progress against the bank.  You need to take care going downstream as you can be going much faster than normal.

Note that river flow speed varies a lot, depending on the breadth and depth. At Hampton Canoe club the river is very broad and may appear not to be flowing that fast but between the islands where the river narrows the flow is much faster.

You should be confident in your ability, and the ability of those with you:

1. Wear a buoyancy aid
2. Use a more stable boat in higher flow rates
3. Paddle with other experienced paddlers 
4. Safely build up experience of how the faster flow affects paddling, steering and turning
5. Dress appropriately for the water temperature (e.g. consider using a wetsuit)
6. Plan ahead for objects and conditions downstream from you
7. Make sure you leave enough room between you and fixed objects such as pontoons, moored boats and trees
8. Keep away from weirs. Paddling above a weir, hug  the opposite bank until well clear.  Avoid going round Taggs Island on high river flow.

• When paddling above a lock cut or near a weir, keep on the side of the river that’s furthest from the weir.  This may mean that you have to paddle on the left bank to be safe.
• Sunbury lock:
  • Sunbury weir has especially strong pull with deceptive currents between lock cut and weir.
  • Ignore river rules in strong flow and paddle on the left going upstream.
  • Below Sunbury weir consider turning early, even consider turning before the ferry.
  • Note that there are two side weirs on the right bank going upstream from Sunbury (towards Walton) that could also be dangerous. 
•  At Molesey lock:
  • Ignore river rules in strong flow and paddle on the left going upstream
  • When the flow is high, do not go round Tagg’s island (in other words, stay upstream of Tagg’s).

You can refer to these sites for updated information:
 

Information	Website
Stream warnings (yellow or red boards)	https://www.gov.uk/guidance/river-thames-current-river-conditions (updates about 11am every day)
Walton flow rate	https://www.gaugemap.co.uk/#!Map/Summary/1224/1352
Weather forecast	https://www.metoffice.gov.uk/ Take note of especially of wind speed gusting more than 30 km/h, fog and the risk of thunder storms
Water quality	https://thames-watch.uk/TestingHistory for reports of regular water quality testing on the Thames
Water temperature	https://dl1.findlays.net/show/temp/thames1 for regular measurements upstream at Shiplake lock