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How much water can I collect from my rain gutters?

Updated: Dec 17, 2021



When we watch the evening news, the weatherperson will oftentimes say things like “Your city received an inch of rain today”, which does not really sound like all that much. We imagine a single inch of rain in a small puddle somewhere & it seems rather insignificant. But what if you knew that a single inch of rain could allow you to collect hundreds and hundreds of gallons of water, if not more? Now that one inch of rainfall seems like an ocean!



So, if you have 2,500 square feet of roof available for water catchment, and a single inch of rain falls one day, we see that:

2,500 X 0.6 = 1,500 gallons of water can be harvested for future use…from only one inch of rainfall!


On average, Americans use about 69 gallons of water per person per day for bathing, cooking, cleaning and flushing toilets – and that is just for indoor water use and does not account for any watering /car washing going on outside. That amounts to about 2,100 gallons a month for each person – or only slightly more than you might be able to collect off your roof in a single rainstorm. Sure, you might not want to use that water for your showers or drinking water, but it can be done…and many people are putting cisterns in their yard and systems in their house to be able to do so.

Just using a rain barrel or two under your downspouts can make a big difference in your monthly water usage and bill. Let’s take a look at one more example to see how much of a difference collecting rainwater can make – If you live in Boston, Massachusetts, which gets an average of 42.53 inches of rain per year, and you live in a house with 1,000 square feet of roof space…

1,000 X 0.6 X 42.53 = 25,518 gallons of water collected each year in Boston, MA.

That’s a lot of water that you can save (and money!) by hooking up and using rainwater collection systems at your house. It’s a big return for a very small investment. I bet you will hear something different the next time the weatherperson says, “your city received an inch of rain today”!


Contact Dovetail Rain gutter for more information on rain collection systems.

OR CALL US 406-585-2979



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