If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year.
Gallons of water on roof.
There are 231 cubic inches of water in a gallon so using our example above divide cubic inches by 231 and you have a total runoff of approximately 1870 gallons of water or 432 000 231 1870 129.
If you capture the rainfall runoff from a storm that just produces 1 10th of an inch of rain onto a 20 by 30 foot roof you end up with a full 32 gallon container full of water with 5 gallons left over.
The answer is definitely yes.
Easy formula to remember.
To a depth of 1 in 1 hour.
Required roof drainage flow rate in gallons per minute 0 0104 x rainfall rate x roof area where rainfall rate is expressed in inches per hour and roof area is given in square feet.
Convert the amount of rain from cubic inches into gallons.
An online drip calculator that calculates the amount of waste from your leaky faucets.
So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.
When you look at the numbers it s surprising how much water you can collect every time it rains.
1 inch of rainfall in an hour will cover 1 sq ft.
Rain barrel supplies list.
Converting this to gallons per minute per square foot gpm ft 2.
Rainwater collection calculator in gallons.
To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above.
For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain.
In this example 600 x 240 x 1 144 000 cubic inches of water divide by 231 to get the number of gallons because 1 gallon 231 cubic inches.
Or maybe a low pressure cell has been napping overhead and your arm is hurting from holding that umbrella while you watch your basement fill up with water.
Take the dimensions of the footprint of your roof and convert them to inches.
A typical outdoor trash can holds 32 gallons.
Can you get enough water out of the gutter to make it worthwhile.
A service by the american water works association.
1 of rain on 1 000 sf roof will yield 623 gallons roof area m 2 x precipitation amount mm amount collected liters other water conservation calculators.
Rainwater can be collected from the roofs using the rain water harvesting method.