### Rain water harvesting

Posted by stephenhinton on August 4, 2010 · Leave a Comment

Rainfall varies throughout the world and per season. For this little problem we are going to explore whether we can use rainwater. We’ll use Scandinavian figures.

GIVEN that rainfall is 500mm per year.

And

Given a house 25m by 10 meters.

CALCULATE how much rain falls on the roof.

GIVEN that the average person uses 180 litres of water a day.

ANSWER THE FOLLOWING:

Would the rainfall on the house above be sufficient to supply a family of four persons all their water needs?

Further work.

GIVEN that a new kind of pump powered by the force of people stepping on it ( a so-called step action pump) pumps one litre per step.

AND

GIVEN that A fit human can produce 80 steps a minute.

ANSWER THE FOLLOWING

How long would a person need to spend per day pumping water from a rain tank to a roof tank to satisfy their daily needs?

FURTHER WORK

Calculate, for your area if the rainwater falling on your

- school
- home
- or other building you spend time in

is sufficient for your daily needs.

Filed under Supplying water