If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year.
Rain fell from a roof.
So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.
To calculate the runoff from any given rainfall.
It isn t uncommon for an area to collect up to 350mm of rain in just one month even in rural areas.
In the form below choose an area s and a rainfall amount to see how many gallons of water fell from the sky onto that area.
Block out distractions to.
However there is a way that you can redirect the rain off the roof so it falls harmlessly out of the way.
You might even want to know how many baths you could get from your rainstorm.
Take the dimensions of the footprint of your roof and convert them to inches.
In this example 600 x 240 x 1 144 000 cubic inches of water.
1 place a piece of standard metal drip edge onto a table or between a pair of sawhorses.
To find how much rain you can collect in an average rain year multiply this number by the average inches of rain.
An average suburban roof of 200m 2 with such a rain fall can potentially harvest 100 000l of rainwater 200m 2 500mm 100 000l.
Keep in mind most rain falls over 2 3 months of a year.