What planet are you on?'s Fiona Regan, a Professor at the DCU Water Institute, explains how Irish households are wasting water and what we can do to change our bad habits.

Water is the most precious commodity in the world, but it is not the most valued. We are wasting water. All of us, everywhere on the planet. In Ireland, we might live in a wet climate but our management of this invaluable resource needs to be improved – urgently – because too much of it runs down the drain. Every household needs to transform its water use for the sake of our children. 

According to reports on gathered data Irish people use on average 120-130 litres of water per person per day. This is lower than the EU average but still higher than the level of 100 litres per person per day that we would like to see because resources are struggling to meet demand.

We are asking everyone to try and use only what they need. The amount of water you use depends on your family circumstances, the kind of home you live in and even what you do for a living. But everyone can play a big role in reducing usage and this has huge benefits. 

Water also has a carbon footprint
Few people pay attention to how clean water arrives to their homes on a daily basis.  There are many stages in the domestic water use cycle, each of which has its own energy requirements. To start, water is transferred from its source to a treatment plant where solids are removed and the water is filtered and disinfected to meet regulatory standards. The water is then distributed throughout the community via pipes to homes, where it is heated for many uses.

After water is used, the wastewater is treated before it returns to the environment. The most energy-intensive segment of the cycle is water use at home. The CO2 cost of water is 80% what we do with it in our homes. There are many stages in the domestic water use cycle, each of which has its own energy requirements.  The energy intensity of water is the amount of energy used per unit of water. All of our water use adds up. The cost in terms of carbon is the volume and temperature of the water we use.  

Irish households use too much water. Or do they? 
In a typical home, almost 50% of all the water you use indoors is in the bathroom. This makes it a great place to start saving water. Toilet flushing, showering and bathing and teeth brushing are the everyday things we use water for in the bathroom. 

Look at the figures. 

The shower:
Is your shower time longer than your favourite song? If it is then maybe your shower is too long. Short showers save water. 

Taking a 20-minute shower sounds like a really long time – though it is not unusual. Reports suggest that 10 minutes and no longer is good for our health. Shorter, cooler showers are generally better for your skin. Overusing soap or showering in hot water can negatively impact your skin and hair. An average shower uses about 10 litres of water per minute. Showers are responsible for 30% of our water use.  

Some showers can use a lot of water, particularly power showers. A very simple shower timer can be used to help reduce the time you spend in the shower. Taking shorter showers is one of the best ways to help save water.

When it comes to washing ourselves, it is obviously important to maintain good hygiene, but replacing a daily bath with a five-minute shower could save about 600 kilograms of carbon dioxide per year, for a family of four. Mixer showers, which combine hot and cold water before the water emerges from the shower head, are said to produce 100 kilograms less carbon dioxide in a year than an electric shower. 

You can get shower heads - low flow showerheads - that simply spread the water around in a more efficient way. So you feel like you get just as wet, but you're only using about half of the volume of water. Try shaving your legs in a washbasin rather than during a shower and use eight litres of water rather than 48 litres.

There are a number of affordable and easy-to-use water-saving devices that can help save water in homes. Some might choose to use a toilet cistern bag. This is a device that fits in the water cistern of your toilet and is filled with water which causes it to expand and displace volume in the tank.

This means that every time you flush the toilet, less water is used.  Some toilets are fitted with dual flushing systems. This gives people the option to use a smaller amount or volume of water per flush instead of the full flush volume all the time, in order to save water. 


The sink
Sometimes in order to wash dishes in the sink we leave the tap running, wasting litres of water. It is always better to place a basin in the sink or plug the sink and wash all the dishes together and then rinse. Rinse water could even be used to water plants.  Keeping the kitchen tap running leads to approximately 150 kilograms of carbon dioxide being released per year. Putting dirty dishes and utensils into a dishwasher uses less energy and less water than doing them by hand.

Using a dishwasher correctly could reduce greenhouse gas emissions from washing up by over 70% compared to doing them by hand. A study has shown that using a bowl for washing up, rather than a running tap, could save more than 600 kilograms of carbon dioxide a year – roughly the same as a return-trip flight between Dublin and Cordoba in Spain.

Bottled water 
Many people buy bottled water because they are not keen on drinking the water from their tap for a variety of reasons. What they don’t realise is that many of the bottled waters have gone through a similar treatment process as our tap water.  So why are we buying it in bottles – adding to our waste and probably exposing ourselves to leaching chemicals from the plastic.  The technology and energy involved in providing good quality water to the tap means that we need to encourage people to get "back to tap".  

Chemicals in the home
On a daily basis, we use a lot of different products in the home for use in the bathroom, kitchen and cleaning etc. Many liquid detergents contain harmful substances that can enter the water system through our drains, wastewater treatment plants and back to our rivers.

If we don’t really need to use these products, we shouldn’t. This choice can lead to cleaner water and less greenhouse gas emissions. Imagine the impact we can have on our environment if we choose to go back to the bar of soap. 

If we just take the bathroom, what we use on our body ends up in the water system. In the bathroom, we use many different products for skin and hair. These products contain many chemicals. Parabens are often an ingredient of liquid soaps and are used as a preservative. You might see methylparaben, propylparaben, and butylparaben on an ingredients list. Phthalates may be used in synthetic fragrances. People generally tend to buy more liquid shower products than solid soap bars.  

Bars of soap use less plastic packaging, and because they are solid and contain less water, they have a lower carbon footprint in terms of transportation. The soap bar also tends to have a smaller list of ingredients when compared with the liquid soaps. Many shower gels and body washes are made of petroleum-derived synthetic detergents and need emulsifying agents and stabilisers to maintain their consistency.

These are difficult to remove in wastewater treatment and these chemical constituents cost a lot to produce in terms of energy. Therefore the liquids generally have a higher carbon dioxide equivalent than a bar of soap.

bars of soap

The 100 litre goal
To aim for 100 litres per person per day would mean we need to have short showers, save on flushing the loo by investing in a dual-flush loo or a cistern bag. Also, it saves up to 6 litres of water per minute if we turn off the tap when brushing teeth or shaving. By keeping a jug of tap water in the fridge, a cool drink is at hand rather than running the tap until the water reaches the temperature you like.  This could save up to 10 litres of water per day. 

The kitchen tap and dishwasher account for about 12% per cent of water used in the home, so, if you wash up by hand use a bowl, or put your dishwasher in economy mode. Remember, it's not just about water volume, we need to reduce the temperature to reduce energy consumption and greenhouse gas emissions. 

Three main messages for a positive impact on water and greenhouse gas emissions:

  • Go back to tap water
  • Short showers save water
  • Ditch the liquid for the bar of soap

Watch the brand-new series of What Planet Are You On? with presenter Maia Dunphy on RTÉ One on Sunday evenings at 18.30.