Water Measurement Tips
Finding Your Water Meter
This does of course assume you have a water meter, you will normally know this from your water bill which will give the meter reading rather than an amount based on the rateable value in the UK. The first problem is to find the meter if you don't already know where it is. It will either be located outside under the ground, in a small enclosure attached to the wall of the property or next to the main water stop valve, often located under the sink. If it is underground it will be a found under a small metal or plastic cover in your drive, garden or nearby pavement and marked water often with the name or initials of the water company on it.. Open the small cover (you may need a large screwdriver to lever it open - look for lip or indentation to engage the screwdriver) and underneath you are likely to find a foam or polystyrene disc which helps protect the meter from frost. Lift the disc out to reveal the meter. It is vital to replace this disc after use.
Reading The Water Meter
There are various types of meter in use including ones that can be read automatically by the water company. In all cases the display will consist of a set of numbers possibly with a few rotary indicators. To read the meter you need to get the complete number of cubic meters of water used. Parts of cubic metres used are normally indicated by the red numbers and/or rotary dials which can be ignored for the purposes of reading the meter. Below are a selection of links with UK information on how to read a range of different meters:
How to read your water meter from Anglian Water
How to find and read your water meter from Thames Water
How to find and read your water meter from Severn Trent Water
Total Water Consumption
This is only possible if you have a water meter fitted. The best way is to keep a record of water used is to check the water
meter reading every few weeks, trying to keep as regular as
possible, calculating the amount of water used per day. To work out the amount of water used subtract the previous meter reading from the current meter reading and then divide by the number of days between readings. This will give the number of units of water used per day. Keeping a record of use will give a good indication as to whether water consumption is decreasing or increasing. A suitable meter reading record sheet can be found in the record sheet section. To reduce the effect of short term variations in the daily rate checking every three to four weeks
works best. To make this simpler and remove the need for manual calculations you can use EnCalcLU an electricity use calculator which is free for personal non commercial use.
Measuring A Leak From A Tap
This is a very simple task requiring a bowl or other suitable container and a measuring jug. Let the tap (turned off) drip into the bowl for one hour and then using the measuring jug measure how much water is in the bowl. The leak rate is the number of litres or gallons in the bowl per hour. Multiply the result by 24 to get the daily amount of water lost. For small leaks it may be necessary to catch the water for say 10 hours. In this case the daily loss is amount of water divided by the time in hours multiplied by 24.
Measuring The Flow Rate Of A Tap Or Shower
This task requires a bucket or bowl and a measuring jug. Run the item into the bucket for one minute and then using the measuring jug measure how much water is in the bucket. The flow rate is the number of litres or gallons in the bucket per minute. The accuracy of this measurement will not be that good. For more accurate measurements use a larger container and run the shower or tap for longer - say two or three minutes. The flow rate per minute is the number of litres or gallons in the container divided by the number of minutes. This method works very well to demonstrate the difference when for instance a normal shower head is replaced by an aerating shower head.
Measuring Water Pressure
To do this you need a suitable pressure gauge and adaptor to connect the gauge to the tap or shower you want to measure. The gauges can be obtained from good plumbers merchants but often it is difficult to find a suitable adaptor to fit particular taps. The only option in this case is to make something up which is not always as easy as it sounds. It is also useful to know the water pressure coming into the house since this can have a big effect on water use. The only option here is to fit a pressure gauge after the main water stop valve.