Risks and myths at Bawsey Lakes

… and how to stay safe and avoid genuine risks

The owners of these beautiful lakes in West Norfolk make it clear that they do not wish people to swim or paddle, and that they consider to do so is dangerous. They haven’t explained what is specifically dangerous about the venue, however, beyond the usual risks of potentially cold and deep water, however a number of risks related to the lakes have been mentioned by them and others. We have examined each risk in turn to try to establish whether it is a myth or a real risk – and explained how to mitigate any real risks. The most effective way to enable people to keep themselves safe is to give them accurate information on risks and how to stay safe.

Details in the table below, showing claim/risk, whether it is a myth or a risk, and how to stay safe, or you can Download it (Word.docx, 8 pages).  Please note that this list of risks is not intended to be an exhaustive list of all relevant risks, and please note the statement on liability at the bottom of the page.

Claim/RiskMyth or risk?How to stay safe
Great Lake Great Lake Great Lake
Machinery, old gantries and large structures in the water, left when quarry closedAlthough theoretically these still could be there, at the bottom of the lake (5 m or more deep), sonar investigations have not found any sign of them, and they don’t show up in drone photos and footage at a level that could affect swimmers. Swimmers would be in the top metre of water.No specific action to avoid these is needed for swimmers, but they should be vigilant. Jumping not a good idea – see below.
Barrels of noxious chemicals thrown in to the water when the quarry closedNot clear what sort of chemicals might have been used in a silica sand quarry, and it is very unlikely that this would have an impact especially on a large lake as any such material would be much diluted.No action needed.
Ironwork and spikes, opposite Bawsey BaySonar investigation found no evidence, other than branches from the adjacent woodland, however low water in 2022 revealed a few pieces of metal, some jagged, at the beach near the West car park. As the water is very clear these should be visible.  Take care if swimming near the woodland edge, look out for branches or other obstructions. Look carefully before getting in, wear swim shoes, and take care. Don’t jump in from the side of the lake.
A pipe that sucks water and will drag swimmers underNo evidence of a pipe, even when this and adjacent quarry were working – documents showed that that was not the case. There is certainly no such pipe operational now.No action needed. Swimmers should be aware of swim failure/cold incapacitation – see below.
Weeds that will drag swimmers under/trap themVery few if any weeds in this lake, and certainly not anywhere near the beaches, probably due to the pH level – see below. Very few weeds in the Brickyard Lake, either. Weeds do not drag swimmers under in any circumstances. Where they are present, they can potentially trap people who jump or dive into them, and they can entangle people, generally in rivers or when doing a circular stroke.No action needed. If swimming where there are weeds, best not to jump or dive into them, and be aware of what to do if you panic. If tangled in weeds, avoid circular swim strokes or reverse the direction.
The water is too acid to be safe to swim inThe water in this lake is relatively acidic, pH 4.5. Formal swim venues are advised to avoid water below pH 6, however more detailed research shows that there are no issues down to pH 4 (incidentally the same pH as drinking water in most of the USA). Rainwater has a pH of about 5, and in these lakes there is no limestone to change that level, then in addition the pyrite which is present in these soils reacts with oxygen and water to create very dilute sulphuric acid to lower it further (information provided by expert geologist and hydrogeologist. Slight risk of skin irritation, especially eyes. No issues reported by swimmers. Read more, www.fondriest.com/environmental-measurements/parameters/water-quality/pH/Be aware if putting face in the water, especially if skin is sensitive. Unlikely to be an issue for most people.
Both lakes Both lakes Both lakes
Deep water, sudden shelving into deeper waterThis might be the case at some beaches, however not at those at Bawsey Bay or the western side of the Great Lake, or the beach at Brickyard Lake. Risk of suddenly going out of your depth, particularly for those who are not confident or good swimmers, also for those paddling.Be aware when entering the water, supervise non-swimmers or weak swimmers or children in your care. Only go into deeper water if you can swim. If not confident, stay within your depth.
Deep water will be coldIt is true that the deeper part of the lake is colder, but the water has different temperatures at different layers, and in certain seasons they mix. Someone jumping in (not a good idea anyway in these lakes) could enter unexpectedly colder water. In spring and summer the top layer of water warms up, reaching more than 20° in summer, and this layer will be deeper in larger bodies of water. Swimming happens in the top metre, which is likely to be warmer. In winter the opposite is true, and the top layer can be the coldest, but winter swimmers are likely to be aware of this. www.outdoorswimmingsociety.com/thermal-layering/Best to avoid jumping into these lakes. Be aware of possible variation in temperatures, and of the risk of swim failure/cold incapacitation – swim parallel to the shore unless experienced.
Very cold water, even in summer, reportedly freezing temperatures beneath the surfaceNot true. The top layer of water in the lakes will warm up from spring into summer, reaching at least 22° in hot weather, and that layer can be very deep especially in a large lake. Swimmers will be in the top layer of 1 m or less, and in summer that will vary less than in autumn.Swimmers should be aware of water temperatures, and if not used to water cooler than a swimming pool should stay within reach of the shore and not get too cold.
Cold water shock will kill in minutes, any season, age or fitness    Cold water shock is a real risk of outdoor swimming, and it is true that it can affect anyone regardless of their age or fitness, and can occur in any season, though much less likely once water is above 15°, as it will be throughout the summer. It is true that it can kill in minutes or even seconds – if someone unused to cold water enters the water too quickly and in particular puts their head underwater. This is because it can cause an involuntary gasp, and if your head is underwater when this happens you will take in water and drown. The shock of cold water can also increase heart rate, which is not generally an issue unless somebody has a heart condition. Those used to cooler water are less likely to experience this because of acclimatisation, unless the water is much colder than they expected. If swimming in a wetsuit, cold water shock can be experienced when water enters at wetsuit, and if out in a lake that could cause issues including panic.  
Podcast with the expert on cold water, Prof Mike Tipton, explains the risks and benefits of cold water shock, managed carefully, www.bbc.co.uk/sounds/play/m001s5hc?partner=uk.
Easily avoided by entering the water body first, not too quickly, and not swimming off until breathing has calmed down which can take 1 to 3 minutes. If starting off outdoor swimming, especially in cooler seasons, best to be aware of medical condition especially in relation to the heart. If wearing a wetsuit, be sure to allow some water into the wetsuit and wait until used to the impact of that cold before swimming off. If not used to cool water, don’t go out into a lake on an inflatable, to avoid cold water shock if you fall in.   Practice Float to Live, so that you can do it automatically if you panic or fall into water. Lie on your back, like a starfish, with your ears in the water, move your arms and legs gently if necessary to stay afloat. https://respectthewater.com/campaign/float-to-live/
Benefits of cold water immersion, including cold water shockCold water shock is actually one of the aspects of outdoor swimming that creates important benefits – the minor stress of carefully controlled exposure to cold can make people more resilient to other stresses in their lives.  Read more, www.waterstones.com/book/chill/mark-harper/9781797213767 – Chill by expert on cold water, Dr Mark Harper. Or in this video he talks about the benefits and how your body reacts and adapts to cold water www.youtube.com/watch?v=0pXLF0sucDUCold water swimming can provide many benefits, done carefully. Look at the info on staying safe in the row above and in the links, and consider doing two aspects of immersion: exposing your skin (or parts of it) for a couple of minutes; placing your face in cool water a few times.
Cramp, caused by cold or pockets of coldCramp can be an issue causing panic and hampering swimming ability. Not generally caused by cold, or by eating before swimming, but by dehydration or excessive strain placed on leg muscles. Panic is the greatest risk from cramp, and that could lead to drowning, but can be mitigated.Prevent by being well hydrated and warming up your muscles before a swim, swim in a relaxed way, build up your swimming techniques and the time you can stay in the water before going far from shore. If it happens when you are in deep water, relax and float on your back, massage the area if possible, or wait until it has passed.
Steep sides making it hard to climb out, especially if coldThis does not apply at most beaches at Bawsey, but the swimming ban might mean people trying to swim from more hidden and steeper places, and it is true that it could be hard to get out especially when cold, leading to getting even colder.Be sure you know where to get out before getting in to swim, and it is best to choose shallow gradual entry and exit points. Be aware that being too cold can affect muscles especially fingers and hands.
[Not mentioned by landowner]
Other risks of cold: Swim failure/ cold incapacitation/ stealth chilling  
Swim failure/ cold incapacitation/ stealth chilling: a real and important risk, not mentioned enough or understood. Deaths resulting from this can mystify, as it can affect swimmers of any ability, but it can easily be avoided with knowledge. If you get cold your muscles don’t work as well, because the body is concentrating blood flow to your core. If you’re in the middle of a lake it can be very hard to get back, and you can sink into the water and drown. Treading water or trying to swim will mean your position becomes more upright making it more likely you will sink into the water. www.outdoorswimmingsociety.com/cold-incapacitation/If not used to cool water, stay near to the shore or do short trips out and back, or stay within your depth, and get out before you get too cold. If you find your muscles not working well, turn onto your back and Float to Live, call for help, and use your feet to paddle you back to shore. Wetsuits can delay stealth chilling and the buoyancy they give can help keep you afloat, but they do not fully prevent swim failure. Swimmers need to be aware of their body and how it responds to cold, and to know when they need to get near to the shore ready to get out.
Other risks of cold: after dropAfter drop. More likely in winter, but possible any time of year. After you get out of the water your body continues to cool for 10 to 40 minutes. At the most extreme this could lead to hypothermia, but is easily avoided. https://openwaterwheway.wordpress.com/2022/11/11/afterdrop-the-post-swim-shivers/Don’t stay in too long and get too cold (and swimmers have to learn how their own body response to cold).  When you get out of the water, don’t hang about, but get dry and put on warm clothes, at least one layer more than you might think you need, and do some gentle exercise. Some consider that wetsuits slow down the process of getting wet clothes off in order to get dry and warm.
Other risks of cold: hypothermiaHypothermia. This is when the core becomes dangerously cold. It can take a while to develop, and someone might not realise it is happening and might even think they are too warm. Signs of hypothermia (IN the water) can include:
-change in swimming technique or speed
-unable to speak
-growing more vertical in the water
-fingers becoming splayed
-blue around the lips Signs of hypothermia (out of the water) can include:
Grumbles – negative mental outlook
Fumbles – slow reaction time, drops things, poorly coordinated
Mumbles – slurs words
Stumbles – appears stiff, loses coordination, difficulty walking www.outdoorswimmingsociety.com/understanding-hypothermia/
Don’t stay in too long and get too cold when swimming, get dry, dressed and warm after you get out. Be aware of the signs of hypothermia (the ‘umbles’) in yourself or others, be firm with another person who needs to get out of the water and get warm, know how to warm yourself or someone up, and know when to call for help. Wetsuits can delay but cannot prevent hypothermia.
[Not mentioned by landowner]
Windy conditions
Windy conditions could make it much harder to swim against the wind, especially if that is your return journey when you are tired and cold. There are no currents in these lakes, however windy conditions could create similar issues. Wind can also make you colder, especially when changing afterwards. Inflatable toys or boats can be blown out from the shore into the lake, and if someone is on them that cannot swim and does not have a life jacket or is not used to the cold that could put them at serious risk.Be aware, factor this in if doing a swim away from the shore. As usual in cold conditions, get dry, dressed and warm as soon as you get out of the water.   Avoid using inflatables if it is windy, supervise any non-, weak or inexperienced swimmers.
Swimmers should wear wetsuits for buoyancy and warmth and to prevent cold water shockSwimmers do not need additional buoyancy, and in fact it can interfere with a good swimming stroke. Buoyancy can be a benefit, if someone has stayed in too long and is far from shore and experiences swim failure, however prevention is abetter way to avoid this risk. Many swimmers choose not to wear wetsuits at any time of the year (though some choose to wear them or other neoprene clothing for part of the year0 – and find that they prefer to be able to get dressed quickly after their swim. Every swimmer is different in their tolerance of cold, and in their level of acclimatisation. Wetsuits can cause overheating in warm water and warm weather, and are generally advised against in such conditions, as overheating is a serious risk. Wetsuits do not prevent cold water shock, in fact can make it more of an issue, if people do not allow some cold water in before swimming off. Experiencing cold water shock when away from the shore can be a serious risk. Wetsuits could delay the impact of cold, in particular swim failure, however do not prevent it completely so it is important to be fully aware of this risk.If you feel you need extra buoyancy, wear a buoyancy aid, but also be aware of your swim capability and don’t go beyond it. If you wish to wear a wetsuit, then do so, but if you don’t, then don’t. Be aware of the differences and issues related to each. It is colder to swim without, so you need to be very aware of your own body’s response to cold, but it is also quicker and easier to get dressed and warm afterwards. If you wear a wetsuit, make sure you allow some water into it before moving off to swim, to avoid cold shock when further out into the lake. Take it off quickly along with any other wet swimwear so that you can get dry and warm quickly afterwards. Be aware of all the risks of cold, which can affect wetsuit wearers, if delayed. Be aware of the risk of overheating in hot weather and warm water, in summer.
Swimmers should use tow floatsTow floats have two purposes. One is to make swimmers visible, which is important when there are boats or other water users you could come into conflict with. The other is to carry things, such as valuables, phones, some clothing. They are not buoyancy or safety devices, and relying on them as such is not a good idea, especially out in a lake, where swim failure if you get too cold hanging about could be an issue. And cheap or worn tow floats can burst, so should not be relied on. There is one other potential purpose for a tow float – finding someone who has drowned, however it is better to understand and follow safety information to prevent this happening. www.outdoorswimmingsociety.com/tow-float-or-not-tow-float/Consider using tow floats where there are boats, especially powered boats. They are not generally needed in other conditions, and can pose a serious risk in choppy waves, in flowing rivers especially if there are branches or other obstructions they can get caught on, or if swimming close to others, such as in a race. Never rely on them as a safety device; only swim within your capability, and if you are getting cold it’s better to swim back to shore quickly rather than hanging about.
[Not mentioned by landowner]
Angling litter, especially hooks and lines
Unfortunately, when there is angling, especially if there are trees or branches, hooks and lines can get caught and left behind, which can be a risk of injury if you stand on them or catch yourself on them. Angling has been introduced in the Brickyard Lake, but is unlikely to happen in the Great Lake because of the pH levels.Wear swim shoes, watch out for litter.
[Not mentioned by landowner]
Blue-green algae
Observed 22 October 2023: a small amount of blue-green algae on the western edge of the Brickyard Lake. Very unlikely to occur in the Great Lake because of the pH levels. The risk to humans is minimal when there is only a small amount, blown onto the edge by the prevailing wind. Avoid swimming in a thick bloom of algae, which can cause skin irritation and sickness if swallowed.Look out for it, avoid swimming where there is a thick bloom, but if the amount is minimal and on the edge, it should be possible to swim in the lake, perhaps keeping your head out of the water and avoiding swallowing any.
[Not mentioned by landowner]
Jet skiing, windsurfing, and other water sports
Other water users can be a risk to swimmers, especially if they don’t see them or can’t avoid them. Unpowered boats can also be a risk.Be visible or steer clear of powered boating areas.
[Not mentioned by landowner]
Jumping into the water
Jumping into water can be a risk – jumping into water that is too shallow, jumping from a height without knowing how to do so, hitting obstructions or other people, can all cause injury. Jumping straight into water without getting used to the temperature first can cause cold water shock, especially if you go through the warmer layers into the deeper colder water below, and this can mean the involuntary gasp can bring in water.There is nowhere suitable on either lake for jumping into the water (this information comes from very experienced height jumpers). If jumping somewhere else, be sure to check for obstructions, check the depth, know how to do it, and get used to the water temperature first.
The lakes are dangerous because people have died in them over the last decadeLakes, like any other water body, have certain risks, but these can all be mitigated, and in fact lakes have far fewer risks than water bodies such as the sea and rivers. People have died in lakes because they were not aware of key safety information or were not able to swim. They died of causes related to cold or swim capability – cold water shock, swim failure, swimming when not capable enough to do that swim, falling off an inflatable, trying to rescue a drowning person. It is utterly tragic that people have died in ways that could be prevented by giving them accurate information. Focusing on trying to keep people out of open water instead will do nothing to keep them safe.Crucial to avoiding such tragedies and to keeping people safe is giving them key water safety information: avoid cold water shock by getting in gradually and not falling in; know what to do if you fall in or panic – Float To Live; avoid getting too cold and stay close to shore unless experienced in cool water; swim within your capabilities; keep an eye on children and vulnerable people; do not get into the water to rescue anyone in trouble, instead call for help, tell them to float, throw something that floats.
Swimmers choosing to swim in these lakes will be responsible for other people copying them and then drowningEvery person takes responsibility for their own actions, and that is reflected in established case law on swimming and liability. The claim makes an assumption that people will drown if they swim in these lakes, which is answered in other points – drowning when swimming is very low risk, when taking account of the millions of people who do it safely every year – and these lakes have far fewer risks than many other water bodies, especially the sea and rivers. It assumes that people are too stupid and lacking in knowledge to keep themselves safe, which is far from the case. It is true that people have been denied accurate information and that this is unhelpful in keeping them safe, and these kinds of statements along with Stay Out policies make it much more difficult for people to get information and to get used to swimming outdoors.
We need far more places, especially benign and relatively safe inland water, for people to swim, to learn how to swim safely outdoors, and we need policies based on evidence, not emotive and ill informed statements.
Swimmers should go to the sea, to rivers and to swimming pools instead of these lakesThe sea and rivers have a range of risks that are not present in a still inland lake, and have a much higher number of drowning deaths (though still very low risk). Additional travel adds risk, as well as being bad for the environment. Swimming pools give an entirely different experience, as well as requiring travel. Lakes have far fewer risks than other water bodies, with no currents, waves or tides. This is a good article examining the relative risks, https://openwaterwheway.wordpress.com/2021/06/29/sea-or-reservoir-which-one-might-be-safer/If swimming in the sea or in rivers or in lakes, be aware of the specific risk factors to these types of water bodies, and of the specific water body, and of information that can make sure you keep yourself safe whichever water you swim in. Much information is available, including here, www.outdoorswimmingsociety.com/category/survive/  
Outdoor swimming is dangerousOutdoor swimming has risks, but these can be mitigated. Outdoor swimming poses a very low risk of drowning, and considerably lower risk than many other activities in life (cycling, driving), and on water (motorboating, jet skiing, angling, canoeing, sailing). www.outdoorswimmingsociety.com/drowning-statistics/ The inaccurate and misleading impression that outdoor swimming is dangerous prevents useful information being given so that people can stay safe, and takes no account of the enormous benefits of this healthy outdoor activity. Giving people false information, for example that the water is freezing, when they can feel for themselves that it is not and in fact is very warm in summer, destroys any credibility and means that they are less likely to believe any genuine safety messaging.There are a small number of tips that can keep people safe from the main risks from outdoor swimming, and the focus should be on making sure people know these so that they can keep themselves safe. Key tips,  www.imogensriverswims.co.uk/blog/issues/swim-play-in-water-safely-q-a/ ; and www.outdoorswimmingsociety.com/summer-safety/    
People should stay out of all open water, no matter how tempting or enjoyable it is to swimSaying Stay Out of open water does not work, does not keep people safe, and behavioural science tells us actually makes them more likely to behave in a risky manner. It is unfortunate that some local safety organisations and landowners are not aware of the latest policies based on research and statistics, or choose not to take note of them.Giving accurate and constructive information is a much more effective way to keep people safe, and is the approach taken by the National Water Safety Forum, based on latest research and statistics, representing all key safety organisations, and of key national landowners and their body, Visitor Safety Group.
shallow sandy edge of large lake, reflecting blue sky

Looking east from the west beach of the Great Lake

Please note: all swims and paddles are always at our own risk. Including a location on this website does not indicate that it is recommended or that it is safe; each must do their own risk assessment each time they swim or travel to a location. Please be aware that the level of risk can change over time, depending on a range of variables such as temperature, weather, time of day or night, personal fitness, and level of fatigue – and so each of these variables will need to be considered by an individual before making their own personal decision on whether to swim, where to swim, and for how long. There is Swim Safety info on this website, and on Outdoor Swimming Society website, Survive section. Please follow the Outdoor Swimmers Code. I accept no liability for the choices that people make. This website is not produced by an organisation, commercial or otherwise, and I am not assuming any legal responsibility for those who read the website, and to the maximum extent permissible by law I exclude all liability in the event of injury or other loss.

Location details for Bawsey Pits or Lakes 

swims and swim places, and related issues