# 620 gallons for 1" water per 1,000 SF?



## BXMurphy (Aug 5, 2017)

My word! I was reading that I would need 620 gallons of water to apply an inch of it to 1,000 SF. https://www.lowes.com/projects/gardening-and-outdoor/make-watering-easier/project

That seems a little over-the-top to me. Are people actually doing this? At city water/sewer rates? After reading that Lowe's article, I'm starting to get worried! Is the 1"/wk. rule etched in stone?


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## J_nick (Jan 28, 2017)

It's not etched in stone but it is a good guideline.

+/- 1" a week for summer. During spring or fall that 1" can be enough for a couple weeks. It all just depends on temperature and ET.

For my lawn I normally do around .5" every 4 days in the 100* heat. I have sandy soil and that seems to be about the max amount of water my soil will hold. I've tried watering the 1" all at once but it still shows signs of stress by day 4.

I have a well so I'm not the most water conscious person here, but I still try to do good cultural practices.


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## g-man (Jun 15, 2017)

Yep, that number is right. 623.376374 To be exact. Yes we do this. I mantain 5678 sqft with city water. I would love to have a well.

1000 ft^2 * 1in (1ft/12in)= 83.3333 ft^3.

1ft^3 = 7.48 gallons.

Therefore, 83.33 * 7.48 = 623 gallons.

Most water companies sell the water in 100 ccf. So 1000sqft at 1in of water will be 0.8 CCF.

For the rest of the world that has moved on to a better and easier system:

To get 25mm of water into 100 m^2 it will take 2500L.

The 1in per week is a guideline not a hard rule. A lot of variables at play (turf density, fertilization, ET (~evaporation from the soil), type of grass), but it is considered a good general practice.


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## BXMurphy (Aug 5, 2017)

Hmph. Thanks, gents.

I have 2,500 SF. Half full sun.

Now I'm curious how much water costs... more fun with math... maybe a separate meter to avoid the sewer charge (which will cut it in half)...

Boy, this gets funner and funner, doesn't it?


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## g-man (Jun 15, 2017)

No need to be curious.

Monthly water bill


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## Eric (Aug 15, 2017)

My water/sewer is .048/cu ft, so to put 1" down on 8k is gonna cost me $32/week! If I get a second meter that number drops to $14!


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## BXMurphy (Aug 5, 2017)

Man, in so many neighborhoods around here, our basements take water. Mine does. I have a sump pump.

Now I'm thinking... drill a well and lower the water table and... justify another new toy for Mrs. Murphy!

I'll play with the water bill app but if what Eric reports is true, I'm probably at $10 bucks a week which isn't the end of the world. And around here... We get humidity with our heat... We all know what a bug in a mayonnaise jar feels like. Our high heat and no rain lasts what, two months?... Maybe?

I'll be fine.

It's funny... I've never put a glass out to measure rainfall until getting bit with the lawn bug. Now? I'm all about the precipitation. Thanks?  But, you know, watching the weather and watching the lawn is really kind of relaxing. The results are really starting to show from my new-found knowledge.

I've been lurking another notorious forum for so long... since June... just dying to get an account to talk to people over there and... all the people i wanted to talk to are all over here... and... friendly!

I never did get an account and don't read there anymore, either! No sense if you can't ask questions like how much water are you using and how do you handle it...

This place is great for guys like me and... YOU! Thank you for being here.


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## BXMurphy (Aug 5, 2017)

Eric said:


> My water/sewer is .048/cu ft, so to put 1" down on 8k is gonna cost me $32/week! If I get a second meter that number drops to $14!


I think my town charges ~$200 bucks to change a meter. You might spend $500 for a plumber to cut it in. Figure $1,000 bucks all-in.... you'll recoup that faster than the ubiquitous solar panels for sure.

Anybody collecting rainwater from their gutter downspout? My little cottage sheds a TON that's just creating havoc at some corners. That could be showered on my flowers for sure!


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## Ware (Jan 28, 2017)

BXMurphy said:


> Are people actually doing this? At city water/sewer rates?


The volumetric rate for water through my irrigation meter is $4.28/1,000gal, so each 620 gallons costs me $2.65 (plus tax). This does not include the fixed monthly fees on the bill (e.g. meter charge), which total $11.54. If I was using the meter that serves my house for irrigation, I would also incur a wastewater rate of $3.80/1,000gal, or $2.36 per 620gal.



BXMurphy said:


> Anybody collecting rainwater from their gutter downspout? My little cottage sheds a TON that's just creating havoc at some corners. That could be showered on my flowers for sure!


I can understand the allure of rain barrels, but I don't think I could ever justify using them. This is just some quick napkin math, but let's say the roof of a home has a dripline that encompasses a 2,500 ft2[/sup] area and you put a 50gal rain barrel at each corner to collect water from the downspouts. During a 1/2" rain event, the roof would theoretically gather 775 gallons of water (if 1/2" of rain is 310gal per thousand ft[sup]2), but the 4 barrels would only have capacity for about 25% of that (200gal). Based on my water rates noted above ($4.28/1,000 gal), each 200gal "cycle" of the rain barrels would only save me about $0.86. If the barrels cost $100ea for something that was even halfway aesthetically pleasing, I would have to cycle them ~465 times to see a simple payback. Then there is the issue of demand - when it is raining enough to get the throughput you would need for them to be effective, your plants probably don't need the water you are gathering. Then when you save a batch for when you really need it, you only have 200gal (or $0.86 worth of water) at your disposal. All that said, I understand there are reasons beyond economics that people choose to use them. :thumbup:


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## BXMurphy (Aug 5, 2017)

Hah! Ware... Ware... Ware...

I got a kick out of that.

I've tended to let my math word problem-solving skills slip over the years. It was fun to watch a guy whip out a napkin and say... "Ok, an inch of water slips off a roof. Water costs..."

That was pretty slick!

I agree... the barrels are out. Just the thought of playing around with pumps and hoses left me cold.


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## dfw_pilot (Jan 28, 2017)

Four barrels definitely wouldn't be enough for much water, and living in the suburbs probably kills the idea of lots of barrels.

Growing up, we an old barn out back. My dad bought a bunch of surplus 55 gallon barrels from a restaurant supplier that held cooking oil. I think he paid a few bucks for each, and we had ~ 18 or 20. They were hidden behind the barn and sat on cinder blocks, with the down spouts pouring into the first and last one. Being elevated, he was able to connect them with a pvc pipe to make a manifold, and then used the water via a hose to water our 1/4 acre garden. It was a nice idea, but I can't imagine trying to water a lawn that way, especially for the price of water.


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## BXMurphy (Aug 5, 2017)

Heh! Just like Daddy to trick out some barrels into a Rube Goldberg machine, ehwhat? I can only imagine what your own children or even the neighbors think of you and your lawn obsession!


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## Jericho574 (May 24, 2017)

The irrigation rate here is the same as the sewer rate so it doesn't make sense to add a meter.


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## Iriasj2009 (Feb 15, 2017)

I used to use five 330 gallon totes to collect rain water ~ 1650 gallons, just enough for 2.5ksqft. Used a 1hp pump that was tied in to my irrigation system. .75" of rain would fill them up and worked great, but maintenance got old and I stopped using them. im just going to invest in a second water meter.


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