# Irrigation Ideas for Large Lawn 2+ Acres



## Deltahedge (Apr 1, 2020)

This is a long post, so thank you in advance to those of you who read it!

We moved into our house on about 2.7 acres last year. Included with the house was landscaping beds and lawn around the house. We have about 20k sq ft (0.5 acre) of tiffway 419 Bermuda and 21 zones of irrigation to water the beds and the 20ksq ft of Bermuda. We currently use city water for the irrigation and have enough water flow and pressure to run 6 rotors per zone. (we use Rainbird 5000 rotors).

While I have 20k sqft of nice looking Bermuda, the other 2 acres of the property is just native grassy and broad leaf weeds, machinery ruts, and hog damage from before the lot was developed.

I would like to irrigate the entire 2.7 acre lot. Buying city water to irrigate 0.5 acres is already crazy expensive, so drilling a well is in my future. I'll drill a well regardless of my plan to irrigate the entire lot or just irrigating my 0.5 existing Bermuda. Just irrigating 0.5 acres, my well would pay for itself in less than 3 years.

Now you have all the background information. Here are some questions I have.

I've talked to some companies about drilling a well on the lot. All the quotes I've received for a well is for a design GPM of around 25-30 GPM.

To put 1/2" of water on 2.7 acres is about 36,000 gallons. If the well is producing 30 gpm, it would take an irrigation program 20 hours to run. (i water 0.5" twice per week, so I could split the land into 2 different days and run half the zones in the morning on day 1, and the other half on day 2)

It seems the options are to drill a bigger well with more capacity, or build some type of water storage onsite. The 30gpm well could pump into the storage for a long time, and then I could use higher HP pumps to from the storage into the irrigation system to water the whole lot in 5ish hours. Because I don't want above ground tanks, I will need below ground storage, or a pond. Below ground storage seems expensive, but I'm not against spending some money because I think this investment will pay itself off someday. A pond could be pretty nice and would potentially add to the aesthetics of the property.

Are there any other options I'm not considering? What pros and cons do y'all see? With something this size, am I into the scope of getting some golf course fairway rotors?


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## Mattsbay_18 (Aug 3, 2018)

With the well quote you received, is the well rated for a 25-30 gpm recharge rate or are they quoting you for a 25-30 gpm pump?

If they are quoting you for a 25-30 gpm pump, then why not get a bigger pump? I've been researching larger pumps myself and I've seen some high flow 4" well pumps that can produce 90 gpm.


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## Justin9314 (Jan 22, 2020)

I had a well installed for 3 acres. They installed a 3 HP variable speed pentair pump on a 5" well. Depending how your lot is laid out, depends on how you design the vacant land. Mine is wide open so I could space heads 35' apart and still get head to head coverage. Ultimately ended with 11 zones which included drip irrigation for the landscape beds. I am using simple Hunter PGP-ADJ rotors, $8/each. Total cost (except for the well) was $4,000 give or take. If you do pull the trigger, my one tip is to over order on your fittings. I mean like over over order. I got tired of taking trips the the store so I started just buying boxes of fittings and retuned them when I was done. I wasted so much time running back and forth on parts that I was missing.


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## Deltahedge (Apr 1, 2020)

Mattsbay_18 said:


> With the well quote you received, is the well rated for a 25-30 gpm recharge rate or are they quoting you for a 25-30 gpm pump?
> 
> If they are quoting you for a 25-30 gpm pump, then why not get a bigger pump? I've been researching larger pumps myself and I've seen some high flow 4" well pumps that can produce 90 gpm.


The pump they're quoting me is a 2HP 30 gpm pump. That's a great idea. I don't know why I didn't think of that.


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## uts (Jul 8, 2019)

Even if you just use 30GPM in an open lot (e.g 200' wide) you can run 5 rotors (40' diameter @50psi)at 6 GPM, in an hour you will likely put down 0.33" in an hour (based on Hunter i20 blue nozzles #6 if arranged in a triangle pattern. You can probably cover the acre and a half in about 8 zones. Divide your watering over 2 days e.g Mon (Prog A Zone 1-4) and Tuesday (Prog B 5-8) and Thursday (A) and Friday (B). Run the system for 6h (1.5h each zone 0.33/h x 1.5 = 0.48" per cycle) and finish watering by 9 or 10am. This is an over simplification in my head. That said how is your lot configured?


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## bernstem (Jan 16, 2018)

Definitely get the biggest well pump you can. Talk to the driller and find out what the recharge rate on the well is expected to be and aim for more if you can. If you can get to 60GPM, it will only take 10 hours to water everything. 90 GPM would be under 7 hours. You can either run larger heads with more flow and range (some golf course heads will run 50+ GPM with 100 foot throw for one head), or run larger zones (at 50+ GPM, you could design a zone with a 0.5 inch/hr precipitation rate using Hunter I-20s with 10 heads and 40 foot throw radius). It will take more planning and require larger supply pipes, but either way is doable.

If you have space for a retention pond, your idea of filling that with a slower well pump and then using it for irrgation is sound as long as it is big enough.


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## uts (Jul 8, 2019)

uts said:


> Even if you just use 30GPM in an open lot (e.g 200' wide) you can run 5 rotors (40' diameter @50psi)at 6 GPM, in an hour you will likely put down 0.33" in an hour (based on Hunter i20 blue nozzles #6 if arranged in a triangle pattern. You can probably cover the acre and a half in about 8 zones. Divide your watering over 2 days e.g Mon (Prog A Zone 1-4) and Tuesday (Prog B 5-8) and Thursday (A) and Friday (B). Run the system for 6h (1.5h each zone 0.33/h x 1.5 = 0.48" per cycle) and finish watering by 9 or 10am. This is an over simplification in my head. That said how is your lot configured?


Edit: I realized for a good pattern you will likely need 2 extra zones running 180 degree with the 360 deg above as well. Add an hour to those times.


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