Water Supply and Use in Your Home

A hot water cylinder can give 30 litres per minute of hot water, if the cold main into the property is only 10 litres per minute, then you will only get 10 litres per minute out to taps.

The simplest way to measure flow rate is to time how long it takes to fill a bucket to known volume. For example, if it takes you 30 seconds to fill a 10 litre bucket, the flow rate is 20 litres per minute.

The local water pressure is set by your water supplier. Legally they only have to guarantee 1 bar pressure and 9 litres/minute flow.

Approximate hot or cold water demand, flow rate litre per second and litres per minute


Litres per second

Litres per minute

Capacity [litres]

Cost per instance of use

Based on rate of £0.002458 per litre

Basin [spray]




2.5 pence

Basin [standard tap]




2.5 pence

Toilet cistern [pre-1993]




6 pence

Dual flush cistern [short flush]




0.6 pence

Dual flush cistern [long flush]




1 pence

Shower [100mm rose]




22 pence

Bath [tap]




37 pence

Using the tables of charges below you can see how much your water bills should be and budget for future use based on current charges.

The following details costs for water and sewerage, extract from United Utilities list of charges

Type of premises Water Sewerage Total
Single person household £105.57 £138.62 £244.19
bungalows £225.11 £232.93 £458.04
Semi-detached houses and bungalows £205.87 £217.75 £423.62
Detached houses and Other household premises £157.78 £179.81 £337.59

Careful users can make much savings by having a water meter fitted. The details listed below will let you compare both methods of payment

Water meter rates



Standing Charge

Price per m³

Standing Charge

Fixed charge

Price per m3






The average bath takes 150 litres to fill. A cubic meter of water has 1000 litres. From the prices above the average bath has 20 pence worth of water. A five-minute shower uses about 90 litres of water which costs about 12 pence.

Don’t forget to add the cost of what goes down the drain! Bath waste water costs 16 pence to get rid of and 10 pence for a shower.

Now total costs for comparison are Bath = 37 pence = £259.00 per year* 5 minute Shower high flow rate = 22 pence** = £154.00 per year* 5 minute Shower standard flow rate = 12 pence** = £84.00 per year*

* based on 2 instances per day for 350 days per year

**Note the shower flow rate is based on at best 18 litres per minute. Many use about 10 litres per minute. This reduces the shower costs to 12 pence [7 pence for water and 6 pence for waste water to sewer]

Green Deal Ecologic Take control of your water don’t pour money down the drain

About aimhome
All aspects of energy efficiency and help with saving money spent on utility bills. Home visits undertaken to assess what is used and explain what can be done to save money. Central heating control upgrades, central heating system power flushing. Energy saving lighting surveys and installation of low energy lamps and lighting. Every day that action is not taken is an added cost in hard cash terms. Call today to see what can be done. Green Deal Ecologic Ltd, improving your world without costing the earth.

2 Responses to Water Supply and Use in Your Home

  1. Dani A. says:

    This is very informative and would be great if I lived in the UK. I’ll definitely share it with my English friends.

    • greendealeco says:

      Hi Dani A.
      Thanks for the comment. It’s great that you share the water saving information in this post. Please contact me if you have any ideas or tips on what energy saving tips and tricks are going on in your area. We all need to get smarter as money spent on wasted energy isn’t refundable!

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