Neuroscience and Water Saving

With our water supply in Cape Town at a record low, what can we learn from neuroscience about how to use our flexible brains to adapt and change our habits - before we reach our last drop?

By Dr Samantha J. Brooks Ph.D.

Those of us living in and around Cape Town are concerned and reminded daily - on flashing signs as we drive along the freeways - that our water usage, combined with a number of dry months, has left our dams at record low levels (12%: July 2017).  Drought warnings are at critical level 4, with people being advised to use only 87 litres per day. Nevertheless, there have been many “water guzzlers”– who used between 100,000 - 700,000 litres of water per month (that’s an astonishing 3,000 – 20,000 litres per day!). Despite this shocking statistic, ingenious people in Cape Town have found new ways to save water and reduce usage: from capturing water by showering over a bowl, redirecting grey water pipes to a water barrel and washing (bodies, clothes and cars) much less frequently. And there’s the slightly crude, age-old adage: if it’s yellow, let it mellow - only if it’s brown, flush it down.  However, even those of us trying to save water are not used to having a limited supply.  So with the situation at its most critical in recorded history, what can we learn from neuroscience about how to use our flexible brains to adapt, cut down and save water?

Habits - like how we use water - are difficult to break, especially when we’ve been taught over and over again that water is good for us (our bodies are supposedly made up of 85% water).  It also feels good to drink cold water on a hot day or after doing some exercise.  And for those of you who don’t like to drink it – soft drinks, beer and wine also contain water!  It also feels good to have a nice long hot shower, to regularly water our gardens to keep them green and to clean our clothes and our cars. Habits are linked to the brain systems that make us feel good – the dopamine reward system – which begins deep in the middle of our brains.  But it’s usually substances such as drugs of abuse, food, alcohol and behaviours such as shopping, social media and gambling – not water usage – that are linked to stimulation of the reward part of the brain.  However, behaviours that we do often – like drinking and using water – become compulsive and we may find it very difficult to change them. 

Water is closely linked to our sense of survival, which could be why, even if we don’t like drinking it, we feel safe when we have easy access to it. Our compulsive, excessive use of water makes us feel good, which stimulates our reward brain networks.  However, being told that we must drastically cut down on our water usage sets us into panic mode, and the panic – or loss – system in the brain is closely linked to our primitive sense of attachment and safety.  When we feel the threat of loss – especially to our very survival – this can activate fear, anxiety, helpnessness and depression, which goes against our feelings of reward and could encourage denial of a problem (‘the water guzzlers’). Our brain’s panic or loss system involves activation of the hypothalamus, pituitary glands (for release of stress hormones), adrenal glands (for release of adrenalin), thalamus, amygdala and hippocampus (all found in the middle of the brain, working in opposition to our dopamine reward system). However, the frontal cortex has direct pathways - via a large gateway in the brain called the cingulate cortex – that help to alter our perceptions of panic, and of the world around us. 

When things need to change, it is the frontal cortex – linked to our sense of self and what we set as our future goals – that help our brain pathways to change, or to rewire. In neuroscience we call this neuroplasticity – which literally means that the brain is plastic and that it can remodel itself (but with ‘your’ help!).  In other words, if we start repeating good habits regarding our water usage, like showering less often, capturing grey water and flushing the loo only when we need to, our brains will adapt.  Our brains will make the physical changes necessary so we can feel less panic about our dwindling water supply.  And if we gradually change our brains in this way, we may just adapt to our current water crisis, so that in the next few years we can get our dam levels back up to normal again.  But the bad news is, if we repeat our usual water usage habits, our brains won’t change and Cape Town will surely – and soon – run dry!

Dr Samantha Brooks is a neuroscientist at the UCT Department of Psychiatry and Mental Health, specialising in the neural correlates of impulse control from eating disorders to addiction.  For more information on neuroscience at UCT and to contact Samantha, see