How Much Rain Water Will Roof Collect

If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year.

How much rain water will roof collect.

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. Colorado the state with arguably the strictest rainwater harvesting laws passed a bill in 2016 allowing for the collection of rainwater with a 110 gallon maximum capacity. 1 of rain on 1 000 sf roof will yield 623 gallons. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain.

Untreated rainwater collected from roofs is not safe to drink. To comply with colorado water law the container must be equipped with a sealable lid. Rainwater collection calculator in gallons. 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. The rain will collect in gutters that channel the water into downspouts and then into some sort of storage vessel. Roof area m2 x precipitation amount mm amount collected liters. Rainwater harvesting is collecting the run off from a structure or other impervious surface in order to store it for later use.

An average suburban roof of 200m 2 with such a rain fall can potentially harvest 100 000l of rainwater 200m 2 500mm 100 000l. Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. Rainwater collection calculation formulas and equations. If you have 1 000 square feet of roof on your house and it rains just 1 inch you can collect 600 gallons of water to be used in your garden for washing your car or just for drop irrigation around your property.

Any container capable of collecting the rain shedding from a roof or patio can be used as a rainwater harvesting system. Rainwater can be collected from the roofs using the rain water harvesting method. Take the dimensions of the footprint of your roof and convert them to inches. Keep in mind most rain falls over 2 3 months of a year.

Traditionally this involves harvesting the rain from a roof. To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above. To find how much rain you can collect in an average rain year multiply this number by the average inches of rain. The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area.

It isn t uncommon for an area to collect up to 350mm of rain in just one month even in rural areas. Roof area ft2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember. When you look at the numbers it s surprising how much water you can collect every time it rains.