Lawn watering gallons

Asked August 9, 2015, 4:37 PM EDT

Here's a new one for you. When reading about how much to water a lawn, usually you will see that you should water so many inches of water. Or, many people will say they water for a certain number of minutes.

How about gallons of water? How many gallons of water would it take to sufficiently water a 225 sq. ft. lawn assuming average draining, average everything, and bluegrass.

Or, how many gallons per square foot would be average to use to water a lawn?

Jefferson County Colorado lawns and turf

3 Responses

Here is an easy way to convert inches of water to gallons for your lawn.

An acre of water covered in one inch of water (called an "acre-inch") is 27,154 gallons. This translates to 0.62 gallon per square foot to apply one inch of water.

So, for your lawn of 225 square feet, you would apply 140 gallons of water to supply one inch of water.

When temperatures are in the 90s and it is sunny, a bluegrass or fescue lawn will need about 1.5 inches of water weekly to stay green and healthy. So, your 225 square feet lawn will need about 210 gallons of water weekly - best split into 2 equal applications about 3 days apart.


Dr. Koski, Thank you so much! I thought I would have stumped you. I should have known better. You have really made me happy, and I want you to know that.

I have a "smart meter" water meter that reports usage automatically during the day to the water dept. I can log into my account and see pretty bar charts showing when I have used the bathroom and flushed the low flow toilet, when I have showered, and when I am probably not home. We all know our privacy is invaded everywhere, but I used to think I could pee in my own home without others knowing it. Nope. Not true.

I am going to use the information you gave me to try to get a benefit from this invasion of privacy. I can water using the sprinkler attached to the hose - say for 15, maybe 20 minutes and then look at my water dept. account and see how many gallons it used (as long as I am careful not to use any other water during that hour period).

After a bit of experimenting, I hope to determine how many minutes to water my lawn to get the needed gallons. I will divide it up as you recommend. I usually also try to split up waterings, letting some soak in and then finishing 30 minutes later or so.

Thank you again.

You are welcome! I'll bet that somehow Google knows about your water use too!? LOL!