As shown on “Drinking Our Rivers Dry?” on BBC Panorama the McRobie family reduced their water consumption by almost 50%, from 443 litres to 227 litres a day. What the programme didn’t show was how they did it… In fact, none of the talking heads on the programme actually mentioned the important role that behaviour change can have on reducing water stress in the UK and yet it is free, empowers the individual, and crucially reduces CO2 emissions produced when heating domestic water as most savings from behaviour change result in shorter showers or shallower baths.

There is a target to reduce water consumption from an average of 150 litres per person per day to 130 litres, a reduction of 20 litres per person. As the programme showed, even families that use at or near the UK average can still make easy savings, purely by changing behaviour. To save water successfully you need to understand how much you use and where, analyse where the easiest savings can be made, and then put that knowledge into practice!

As Jamie explains (in his excellent post on the programme on the Panorama Blog:

“Before we thought about our water usage our typical use was as follows:

  • we didn’t time our showers,
  • the Kids had nice deep baths
  • we put the dishwasher on every night irrespective of whether it was completely full
  • clothes washing sometimes happened with half loads
  • used both buttons all the time on the dual flush toilet
  • ran water just to flush waste food through the waste disposal unit
  • sometimes we would use the hosepipe on the garden (quite rare mind as most of the time we would use water from the water butt)”

The simple changes

Over the week that we logged the family’s water use, the above behaviour resulted in an average use of 443 litres per day for the whole family and a wide range of 260 to 600 litres per day. The challenge was to see by how much they could reduce this.

After chatting with Cath we made some easy changes which were:

  • Cut our showers down to 4 minutes
  • Reduced how full we ran the bath – we used the same 4 minutes timer for the shower, but this time used it to time how long the taps were on for – in 4 minutes our bath filled to approx 10cm.
  • Washed pans up by hand, thus creating more space in the dishwasher for other items.
  • Only put the dishwasher on when it was completely full
  • Only put the washing machine on when we had enough clothes for a full load
  • Used the dual flush toilets correctly.
  • Used the left over washing up water to wash down the food waste into the waste disposal unit”

All of the above changes reduced their usage to 227 litres a day with a daily range between 125 – 310 litres per day. So let’s put numbers on some of the changes…

The numbers

Shower: The biggest savings came from reducing the time they are in the shower and for the kids, how much water they use in the bath. The family has two showers. The one they use most is a walk in shower which has a large shower head. Luckily it is flow regulated and the flow is only 8 litres/minute. However ten minutes at 8 litres a minute is 80 litres a day; over half the UK average water consumption used every morning in the shower. By reducing their shower time down from ten minutes to four minutes Marie and Jamie each save 48 litres of water a day.

Bath: I love the idea that the children have cut their bath use down to four minutes as well in so far as they fill the bath up for four minutes using the timer. Jamie says it fills to about 10 cm deep. That’s probably about 60 – 80 litres of water in the bath, which is a saving of between 80 – 100 litres per bath.

Toilet: The family has a 6/4 litre dual flush toilet. If the family use their toilet at the UK average rate of 5 times a day at home, by ensuring they always use the short flush when they have just had a wee, the family will save 32 litres of water per day.

Dishwasher: Most people who have a dishwasher don’t use it as efficiently as they could. The family’s dishwasher uses 14 litres of water each time they use it. They halved their dishwasher use.

Image of Cath

Can they keep the savings up? I think it may prove difficult as the kids get older and start to want to spend hours in the shower, but I certainly think they will continue to use less than 130 litres per person per day.

Can behaviour change help save the Kennet? Cath analyses the Mcrobie family’s water consumption in more detail –

Read more.

Top tips for saving water!

Spend less time in the shower
If you shower once a day in a shower with a flow rate of 8 litres/minute and reduce your shower time by five minutes you will save 40 litres of water per day. Over 1 year you will save:

  • 14,600 litres of water, 569 kWh of gas or 452 kWh of electricity
  • £25 (Thames Water area), £23 (gas) or £50 (electric)
  • 140 kg CO2 from heating the water by a gas boiler or 301 kgCO2from heating the water by an electric immersion (both include 22 kg CO2 from cold water)

Have shallower baths
If you have a bath once a day and have a medium bath instead of a deep bath you will save 50 litres of water a day. Over 1 year you will save:

  • 18,250 litres of water, 803 kWh of gas or 620 kWh of electricity
  • £31 (Thames Water area), £32 (gas) or £68 (electric)
  • 199 kg CO2 from heating the water by a gas boiler or 371 kg CO2from heating the water by an electric immersion (both include 22 kg CO2 from cold water)

Always fully load the dishwasher
If your dishwasher uses 14 litres of water per wash, and you halve its use (from once a day to once every other day) over the course of a year you will save:

  • 2,555 litres of water and 72kWh of electricity

Don’t leave the tap running while you wash up

Drinking Our Rivers Dry