# New Guy! Need irrigation help



## scott in nashville (Sep 25, 2019)

Hello everyone!

New guy here, first post. I have the world's largest residential irrigation system on a 1.2 acre lot in Nashville, TN. 36 zones (16 grass, 20 bed) of pure 100% money burning watering glory. Probably 100 heads in the beds and 40 or so in the grass. In the summer months, my water bills can be over $800. After installing 3 Rachio units, that dropped to around $650.

When we bought the house, we noticed that it had a large irrigation system, little did I know it would become my arch nemesis. The system is somewhere between 10 and 20 years old, and it's had a leak somewhere since day one. When the system is on at the main valve, you can see the water meter churn a tiny bit. When off, it stops. I'm sure there's a valve somewhere that's leaking, but I have yet to find it.

All that aside, I'm thinking of redoing all of the heads to more of a water saving type. I'm a DIYer, so the labor is "free." With that said, here are my questions:
1) Most of my bed heads are rainbird 1800's. I'm thinking of swapping the nozzles to HE. Smart?
2) All of the grass heads are rainbird rotaries. Is there an HE equivalent? I have yet to see one.
3) Do I proactively go and replace all of the valves? I'd have to find many of them first, but is that wise?

I may just be stuck with the decision to have nice landscaping and lawn or not pay for water. I'd be happy to get under 450 a month in the dry season, that'd seem like a major win. Any and all suggestions are welcome!


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## wking (Jun 7, 2019)

Don't know much about the irrigation heads, but have you considered a well for irrigation only? Seems like it would pay for itself quick @ 800/mo.


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## Slim 1938 (Aug 24, 2019)

Wow! That's all I got. Wow!


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## cldrunner (May 14, 2019)

I also have a big yard to water (20,000 sq ft) plus beds. I am new to this forum and also struggle with Texas Bermuda lawn watering needs. In my town I pay $3.80 per 1,000 gallons, 2,001 to 8,000 gallons and $4.82 per 1,000 gallons in excess of 8,000 gallons.

Water requirements for Bermuda lawns are usually 1 to 1.5 inches of water per week(or 630 to 945 gallons of water per 1,000 square feet of lawn). My feeling is that if I want an A+ lawn I need to put down 1.5 inches per week either by rain(not much here in North Texas this summer) or irrigation. If I want a A lawn I need about 1 inch per week, B+ lawn about .5-.75, and a C lawn .25 inches.

I don't know about TN but in TX we have a website run by Texas A&M called watermyyard.org which gives me an e-mail and text every week with my watering requirement based on Evapotranspiration (ET) which is a measurement of the total amount of water needed to grow different grass types.

Your Rachio system figures all this stuff out for you. The only problem is that unless you have a weather station in your backyard it is not going to know exact water requirements. In addition an A+ lawn is in the eye of the beholder. My neighbor may think an A+ lawn is his whole lawn covered in green weeds and not watering (hey he has groundcover).

Also, many of us do not have perfectly installed irrigation systems that have the same heads on each station, watering concrete driveways, neighbors that water my lawn with a strong north wind, and other variables. For instance my spray heads provide 1.83 inches an hour and my rotator heads provide .44 inches an hour. Some parts of my yard are partially shaded by the house during the day while other areas are in full sun in the same watering zone. It is really crazy to think of all the factors including soils and even slopes.

Given all that I have decided personally that If I were to receive no rain water in a whole month I will not put down more than 9K gallons a week which for me is about .75 inches. That means in the hottest hottest Texas summer month I am never going to spend more that about $160 in irrigation. I have tried to tweak each stations(16) minutes depending on the requirement of all these factors and how I want each part of the lawn to look. Take a reading of your meter before and after watering minus the beds. Most weeks I water 1-2 times based on my schedule and possible thunderstorms that never arrive when forecasted .

Good luck in your watering!


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## g-man (Jun 15, 2017)

@scott in nashville changing the heads will not reduce the amount of water your lawn needs and it should not save you $$$ unless you are having runoff. Getting a well might save you $ if it has enough capacity for 1.2acres.


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## scott in nashville (Sep 25, 2019)

Thanks for the replies guys. I have researched a well, but the ROI isn't there. Middle TN is built on bedrock, so you have to drill a long way to get to water. There is also no guarantee that if they hit water that it will be enough, so they recommend water holding tanks of 3000 - 5000 gallon to be buried as well. All in all, a $20k venture. Basically the months of July, August, and September are $650+ a month. When irrigation isn't running a lot, it can be sub $150 which I can manage.

I do have older PGP heads from Hunter which are known leakers around the stem. So, I think I will start by identifying those heads and replacing or fixing them. There are known HE heads that are supposed to water at the same rates with less waste, so I was wondering if anyone had any experience with them?


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## Ware (Jan 28, 2017)

scott in nashville said:


> ...There are known HE heads that are supposed to water at the same rates with less waste, so I was wondering if anyone had any experience with them?


As @g-man mentioned, there are heads that offer lower precipitation rates than others, but it takes ~625 gallons of water per thousand to put down an inch of rainfall or irrigation no matter how you slice it. Heads with lower precipitation rates can help prevent waste if runoff is a concern (e.g. on slopes), but modern controllers with cycle-soak functionality can accomplish the same thing.


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## adgattoni (Oct 3, 2017)

Might be able to get away with less total water through immaculate use of Wetting Agents FYI.


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## Delmarva Keith (May 12, 2018)

Irrigating 1.2 acres that includes an acre of turf on only $650 a month is pretty good. I have about an acre of landscape total, 20k is turf, and have an irrigation well, but my equivalent water cost would be around $575 per month in the Summer. I'd encourage you to really go over your entire system design and try to get the most even coverage you possibly can (and of course locate and fix any leaks) and really dial in what each zone needs versus what you apply to avoid water waste, but aside from that, you have a lot to water.


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## Slim 1938 (Aug 24, 2019)

Just a thought but maybe get rid of the heads in the flower beds and go with drip line. With the amount of heads you have I think it would save you tons of water usage. Just my 2 cents and not backed by any professional data.


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