A few days back, the managing committee of our society implemented restrictions on the usage of water. Which got me to do an experiment I was meaning to do since a very long time. The aim of the experiment was to understand how much water does an average household consume.
This experiment is not scientifically correct, but can give us a general idea of the usage pattern.
- I used a regular plastic mug to measure water
- To mark the mug at the 500ml and 1L levels, I filled & emptied a 500ml cold drink bottle.
- I calculated the time it takes to fill the mug upto the 1L mark by fully opening the tap.
Water flow rates
- Wash basin taps: 17 sec/L (average of 9 readings taken across 3 wash basins)
- Kitchen tap: 15 sec/L (average of 3 readings)
- Shower: 5 sec/L (average of 3 readings)
- Flush: 4L / flushing (taken from jaguar website)
- Washing hands ~ 1 min = 3.5L
- Shower ~ 1 min = 12L
- Washing vessels ~ 1 min = 4L
For a family of four
- Hand washing : min. 4 times for ~ 1 min / day : 4 * 4 * 3.5 = 56L
- Toilet flush : min. 3 times / head : 4 * 3 * 4 = 48L
a. shower : min. 15 min / head : 4 * 15 * 12 = 720L
b. Bucket bath : min. 2 buckets of 15 L = 4 * 2 * 15 = 120L
c. Bath tub : Data Not Available with me
Washing machine : 55 ~ 70 L / load ~ avg. 60L / load
Dish washing :
a. Machine : 10 ~ 20 L / load ~ avg. 15L / load
b. House help : 25 min ~ 100L
Wet mopping of house (including terraces) : ~ 4 buckets of water ~ 4 * 15L = 60 L
- Watering of plants : 2 buckets * 15 L = 30 L
- Excluding 3a, 3b, 3c, 5a & 5b = 254 L / household
- Depending on usage, addition of 3a, 3b, 3c, 5a or 5b can be done.
- As per BIS 1172:1993, for a community population of more than 1 Lakh with a full flushing system is 150 - 200 lphd (Liters per head per day). From this 45L is assumed for flushing.
- if we assume that out of the 4 members, 2 members use a bucket and 2 use a shower for bath, ~ 420L is used for bath.
- Based on general perception, very few dish washers used, hence we add ~ 100L of water for dish washing.
- Total water consumption for a 4 member house goes to ~ 774 L
- We are hitting the upper level of BIS standards for water consumption.
- Internet search for water consumptions by washing machine & dish washing machine.
The real reasons for publishing the results of this experiment are aptly captured in this XKCD cartoon