How Much Does It Cost To Water Your Lawn?

 Have you ever wondered or been curious how much it costs to water your lawn?

So to answer this, I'm first going start with a football field as an example. The reason I'm using the example of a football field is because wit is easy to visualize. We know what a football field looks like. At the end of this video, I'll break it down to how much it costs to water a 1/4 lot.

So let's go ahead and start with a football field. We know that a football field is approximately 360ft by 160ft. When we multiply those two numbers, we get a total of 57,600 square feet. But for this example, I also want to convert it to acres because if we know the acreage of a football field, then we can run these numbers backwards. And if you have a smaller yard, like a 10th of an acre, you could calculate that out, etc.

So let's convert a football field over to acres. The first thing we have to do is know how many square feet are in an acre. This is a well known number and is exactly 43,560 square feet. When you divide 57,600SF (football field) by 43,560SF (acre), you get 1.32 acres; that is how many square feet are in a football field. So that's what we're talking about here. How much does it cost to water 1.32 acres of turfgrass.

Now what we're going to do is assume that we are watering grass. On the average, 1-inch of water per week is typical throughout a season, and is close to the plant water requirement. This is going to be more in the peak summer, and it will be less in the spring and fall, also known as the shoulder seasons.

This can vary depending on what area of the country you live in, what type of grass you have, and the weather. But a general rule of thumb is about 1-inch of water per week, and using 1-inch actually helps make the math easier because in order to understand how many gallons it takes to cover a football field (1.32 acres), we want to first calculate how many gallons are in one acre.

How many gallons of water are in one acre inch?

There are 27,154 gallons in 1 acre inch of water. So to understand how many gallons is required across the football field (1.32 acres), we just multiply 1.32 by 27,154 gallons, and we get, 35,843 gallons. There it is, folks, 35,843 gallons to apply one inch of water across the football field. And again, that's for one inch of water.

Next up, let's talk about water cost. For this example, I'm using the city of Ann Arbor, Michigan, because I'm in Michigan and the University of Michigan football teams are doing pretty good this season.

So let's just assume for this example that we are the football field at The University of Michigan, alright?

A lot of water agencies have two rates. One is the water rate, one is the sewer rate. If you have a deduct meter on your irrigation systems, oftentimes you don't have to pay the sewer rate. So in Ann Arbor, Michigan, the water cost $11.17 per CCF, and the sewer rate costs $6.33 per CCF.

What is a CCF?

A CCF is a hundred cubic. Again, it's a number that doesn't mean that much unless you're in the water business. What we do need to know is how many gallons this is, and we need to know the price per gallon. What we know is that one hundred cubic feet is equal to 748 gallons. So that's our magic number, 748 gallons.

When you run that math, the water only rate in Ann Arbor is $0.015 per gallon and the sewer rate is $0.008 per gallon. For this example, we are going to combine the total, because not everybody has a sewer deduct meter on their irrigation system. So the combined cost of water in Ann Arbor, Michigan is $0.0235 per gallon of water. That is the cost per one gallon of water.

When you think about it, it's pretty amazing, right? How much do you pay for a bottle of water at Starbucks? It's like 3000% markup. 

So now let's run our math, and we know that we were using 35,843 gallons for the football field, right? That was our total consumption for one acre inch. And we know that the price of water is $0.0235/gl, so the total cost of the water, when we multiply that out together, we get $842.31, and as a reminder, that is the cost per week.

Crazy, isn't it? $842.31 per week to water a football field.

If that was the cost to water a football field, and the football field is 1.32 acres, how much would it cost to only water 1/4 acre?

Okay, I already ran the numbers backwards for you, and a 1/4 acre lot would use 6,788 gallons. When we multiply that number times the $0.235, the price per gallon, we get a combined total of $159.52. Again, this is for one week, to apply 1-inch of water, across 1/4 acre lot. If it was just turf grass and we applied one inch of water, 6,788 gallons for a total cost of $159.52.

The final thing that I want to review with you is what its costs per irrigation cycle if you watered 3-days a week. If we had three watering days: Monday, Wednesday, Friday and your system comes on at 9:00 AM and it waters, and at the end it applied one inch of water.

You would have three watering applications and we had our total, remember of $159.52. We divide that by three. We have a daily or an application total of $53.17. That's every application, $53.17 each watering day.

Now, the reason that this is important is because there's a lot of talk about rain sensors, and do rain sensors save money, etc.

What I can tell you is that, using this example, if a rain sensor skips a cycle, you could now save $53. Every time your irrigation system runs, it's going to cost you $53.17, so if it doesn't run, you save that money.

Let's say your irrigation professional wants is going to charge you $200 to install a rain sensor.....that means if it skips four times, it just paid for itself. What this also means is that if your contractor comes and start your sprinkler system in late April, maybe in May, maybe even in June, and they turn that dial to auto, it's going to start watering like this...

So every time it runs, it could be costing you $53. So keep in mind that every time your sprinkler system operates, water is money, and every time your system doesn't water, you save money.