Water can be caught off roof areas and stored in rain tanks. Roof water is the least polluted and easiest to treat for drinking. We use plastic tanks (either 5000 or 10 000 litres) at schools. We build a base and fill it with rubble and then place the tank.

Here is how you calculate your water storage need:

Calculate the following:

Household consumption per day ____________________

Household consumption per week ___________________

Household consumption per year ____________________

Calculate the surface are of your roof         ____________________

Multiply the surface area of your roof by your average rainfall    _______________________

(This is the amount of rainfall it is possible for you to store each year)

Find out the average longest period of time between good rain fall   ___________________

Now if you work out how much water you will use in this dry period, you can calculate how many tanks you need.

Dry period x Water consumption                        _____________________________

 (This is a minimum amount as it is always best to have extra surplus)

Estimate the storage facilities you need to hold this amount _______________