Any irrigation experts in here?

[HX_Guy]

Starting to get the backyard landscaping project underway and trying to figure out the irrigation system.
This is the plan I've come up with, if anyone knows about this stuff, could you critique it and tell me what's good and what's not?

The backyard size is 60' wide X 43' deep (from the bay window edge to the back fence).
The blue lines are for sprinklers and I have it setup on 2 valves, 9 sprinklers per valve. The yellow lines are for bushes and trees (on 1 valve) and the red lines are for the palm trees around the pool and two pots (on 1 valve).

The brown areas are pavers and I tried to keep as much of the piping from not being under the pavers as possible. The wide area near the top I'm going to run a 4" sleeve and run the pipe through that. The grey area around the edges is gravel and the rest is grass (blue area showing the pattern of the sprinklers).

Few questions off the bat...is 1 valve enough for all the bushes/trees? Do I need the palm trees/pots on their own line/valve or should I just tie it into the yellow line? I'm going to run PVC pipe for both the sprinklers and the dripper system.

 

[sdv]

I am not an expert, but based on what I have seen and experienced, I would not put more than 5-6 sprinklers on one valve with 3/4" pipes. You may not get enough water pressure to properly run more than 6 sprinklers per valve

 

[Shane1]

I'm on my third DIY sprinkler system so.....I'm far from an expert but have learned from my mistakes. More valves and zones are better. 9 sprinklers on one valve is to much in my opinion. Like SVD says 6 is about right. If a sprinkler says you will get a 15' radius out of it you will get about 12ish. I would run all drips on one valve and just run that valve longer if need be. I personaly would not put a tree with a big root system in a grassy area. It's been my experience that the roots will come to the surface due to the shallow watering from the sprinklers. At least thats how its been for me in the past in my neck of the woods. Your layout looks interesting and eye catching I would love to see it when its all done and filled in. good luck.

 

[janthony]

I recently owned and operated a lscape and irrigation company and I have installed dozens of irrigation systems from 2 zones to 32 zones, although I am still probably not the most experienced on this site. I'll give you my two cents though. You need to know how many gal per min of volume you have on your main lines. It is not how many heads are on a zone, it is how many gal of water per zone. A 3/4" water meter will allow around 15-18 gal/min after any distance of pipe to the house. For example-large lawn rotor heads use around 2.5 gal/min, so to be safe 6 heads x 2.5 gal = 15 gal/min. Most spray heads accept many different nozzles for each need. Lets say 1.5 gal/min average. So on these you could safely go 10 heads x 1.5gal = 15 gal/min. While pressure is a factor, as long as it is 55-60psi at min you will be fine. Also consider precipitaion rates. As you see on your drawing, some heads overlap and some areas dont get enough h20. Replace nozzles in the heads accordingly to fine tune a balanced precip rate. One other problem I see is all your valves are in the same location and you are basically end feeding the lines. This causes the first head in line to get more water than the second, and the second more than the third and so on down the line. When you get to the last head, it may only put out half the water that the first does. If you are able, carry the main line to the center of each zone and center feed the lines so it balances the volume and pressure. If this is not possible, you will definitely need to adjust nozzles later to restrict flow gradually down the line. Sorry if this was to confusing. And by the way they are right, more valves just give you more control so don't skimp on valves now-trust me way harder to change after the work is done. TEST EVERYTHING WITH WATER BEFORE YOU COVER!!! Feel free to message me if i can help more.

 

[janthony]

By the way, I'd run 1" PVC, not 3/4". Waaay more water volume for not much more $.

 

[HX_Guy]

Thanks for the replies guys.

The situation with the valves is that I already ran a 5 wire line to the backyard from the front (irrigation controller is already installed and a 3/4" line is coming from the main supply to the backyard and capped off right now).

In the front yard, I have 12 sprinklers on one valve and it runs great so even though the backyard will be a longer run, I was hoping I can do 9 sprinklers per valve.
I'll be using spray head sprinklers, an assortment of 4', 6' and 10'.

About the trees..I am going to use two of these perforated stakes per tree to get the roots to grow deep vs at the surface, hopefully they work well. Anyone have experience with them?

 

[Divin Dave]

I installed my own irrigation system. 14 zones. I found this irrigation tutorial online. This BY FAR explains the ins and outs of lawn irrigation more than any other website out there. I followed to a tee and my irrigation system works flawlessly.
I swear by this and refer back to it all the time. It explain why in somewhat simplistic terms things are they way they are. And its also entertaining.

http://www.irrigationtutorials.com/landscape-sprinkler-system-design-tutorial/

 

[HX_Guy]

Thanks Divin Dave, I will definitely read up!

Going off the advice on here and a couple other forums, I've rearranged the system a bit to have the trees on their own line and the bushes/ground cover/pygmy palms on the same line. The sprinklers are still split up between 2 valves.

I added in a landscape lighting run as well (white) from the side of the house to both sides of the yard. One run is ~155' and the other is ~200', using 10 gauge wire I think it should be fine. Not sure if I need two transformers or one bigger one.

Nice thing is I designed it in Photoshop so I can show individual layers for each valve, and it's also to scale with the backyard so I can easily measure distances without actually going outside.

Trees valve...

Sprinkler valve...

Bushes valve...

Lighting...

 

[Shane1]

I have no experience with those perforated stakes. You might want to take a look at established yards and common areas in your city that have the same type of trees you are planting. If they dont have roots at the surface I would try and figure out what they did and copy it.

 

[anonapersona]

About the trees..I am going to use two of these perforated stakes per tree to get the roots to grow deep vs at the surface, hopefully they work well. Anyone have experience with them?

At that website they describe those as drip watering stakes. One needs to be careful trying to mix heads, that is, the balance of volume and pressure is important to making it all work.

Furthermore, some trees always want to put out surface roots. The best thing is to pick your trees to avoid that problem, or give up the grass and mulch where the roots are, then allow some sort of ground cover to fill in where it will.

You can help the tree at the start by digging a proper hole that encourages deep rooting, then by watering properly to allow water to percolate down into the ground rather than running off the surface. That is, run a short cycle of 5 or 10 minutes then return for a second round or even third round to get the watering time you need. The first burst of water will soak in then move deeper. Local experts (master gardeners connected to the county office) can tell you what sort of soil you have and what the water penetration time might be. Clay locks up tight and requires a huge time to soak down into the soil.

Studies show that high quality compost added to the soil in a very thin layer improves soil permeability while encouraging beneficial fungi and bacteria which aid root uptake of water.

I did not look at the tutorial posted but you seem to have been pointed in the right direction with the instructions to determine the delivery pressure and volumes for that math is what makes the system work. All too many systems are done by "rule of thumb" when the math should have been worked out properly.

I do note that you do not have complete coverage in your head spacing. You need to have coverage from two directions wherever possible. Head to head coverage. So on the left half of the drawing, there are large parts in the center of the grass that do not have sufficient coverage. The grass on the right side has proper spacing. Space those heads closer together so that the circle from one head touches the next head. Easiest to arrange a tracing paper grid of the max spacing (15' triangles or whatever) and move it around to see what works best.

 

[jblizzle]

Are you sure it is within code to put low voltage lighting that close to the pool? I thought it had to stay at least 10 feet away. ... or maybe it is allow with some special equipment on the transformer.

 

[stebs]

Just my thoughts...

First off, the number of heads on a zone is worthless. like Janthony said, total # of gallons per zone is the info you need. Just because you have 12 heads per zone up front tells you nothing. how many gallon per minute do those heads use? My front yard is running a 5/8" meter on a 1" line and I think my biggest zone is around 30gpm. It hammers like a mother**** in the house when each zone shuts off and its only a matter of time before we have a major plumbing catastrophe in the house. Other problem is, is that when something using water in the house comes on like a toilet flushing, my pressure to my heads drop considerably and I have no pressure in the house when the system is running. To make a long story shorter, you need to focus more on how many gal per minute per zone.

Before you get crazy doing the design, you need to figure out what your water pressure is and how much flow you can get.

In all honesty, looking at your drawings, you're gonna have problems. In my opinion, since you have all those curves, go to smaller heads and use more of them, even if it means adding extra zones. spray nozzles are a little more forgiving than rotors when it comes to water volume and pressure. look at how the colors darken as they overlap. when the really dark areas look good, the really light areas are gonna look like ****. If you overwater to compensate, then the dark areas are gonna turn into the wetlands. "head to head" coverage is key.

As for the wire already being ran, that's no big issue. it can be extended, properly of course.

Remember this, the old adage of pay now or pay later comes into effect here. You can try and skimp on it as much as you can now, but you'll probably pay back more than what it would have costed to just do it right the first time down the road in repairs and re-working things. Might as well take care of it all now so you only have your yard torn up once rather than several times down the road.

 

[Richard320]

My observations from fighting with what I have to work with at my house:
1) Edge sprinklers tend to water the walkway as much as the lawn. They never work as well as you think they will. I wish mine were in the center of the lawn and then I could fine-tune the spray with the adjusting screw to just reach the edge.
2) Make a careful, detailed map of where your pipes are. Some day you may want to plant something different, or stake out a swingset, or install a clothesline tree, and you don't want to go pounding the sleeve through your pipe. And no, I didn't do it, but it's a real fear! One of these.

 

[HX_Guy]

I recently owned and operated a lscape and irrigation company and I have installed dozens of irrigation systems from 2 zones to 32 zones, although I am still probably not the most experienced on this site. I'll give you my two cents though. You need to know how many gal per min of volume you have on your main lines. It is not how many heads are on a zone, it is how many gal of water per zone. A 3/4" water meter will allow around 15-18 gal/min after any distance of pipe to the house. For example-large lawn rotor heads use around 2.5 gal/min, so to be safe 6 heads x 2.5 gal = 15 gal/min. Most spray heads accept many different nozzles for each need. Lets say 1.5 gal/min average. So on these you could safely go 10 heads x 1.5gal = 15 gal/min. While pressure is a factor, as long as it is 55-60psi at min you will be fine. Also consider precipitaion rates. As you see on your drawing, some heads overlap and some areas dont get enough h20. Replace nozzles in the heads accordingly to fine tune a balanced precip rate. One other problem I see is all your valves are in the same location and you are basically end feeding the lines. This causes the first head in line to get more water than the second, and the second more than the third and so on down the line. When you get to the last head, it may only put out half the water that the first does. If you are able, carry the main line to the center of each zone and center feed the lines so it balances the volume and pressure. If this is not possible, you will definitely need to adjust nozzles later to restrict flow gradually down the line. Sorry if this was to confusing. And by the way they are right, more valves just give you more control so don't skimp on valves now-trust me way harder to change after the work is done. TEST EVERYTHING WITH WATER BEFORE YOU COVER!!! Feel free to message me if i can help more.

Great info janthony, thank you. How do I go about finding out the gal/min of my main line and the rate of each sprinkler? In the front, I used Toro sprinklers, is that something I should be able to get from the manufacturer or the place I bought them from? I will be using spray heads, not rotary.

 

[HX_Guy]

At that website they describe those as drip watering stakes. One needs to be careful trying to mix heads, that is, the balance of volume and pressure is important to making it all work.

Furthermore, some trees always want to put out surface roots. The best thing is to pick your trees to avoid that problem, or give up the grass and mulch where the roots are, then allow some sort of ground cover to fill in where it will.

You can help the tree at the start by digging a proper hole that encourages deep rooting, then by watering properly to allow water to percolate down into the ground rather than running off the surface. That is, run a short cycle of 5 or 10 minutes then return for a second round or even third round to get the watering time you need. The first burst of water will soak in then move deeper. Local experts (master gardeners connected to the county office) can tell you what sort of soil you have and what the water penetration time might be. Clay locks up tight and requires a huge time to soak down into the soil.

Studies show that high quality compost added to the soil in a very thin layer improves soil permeability while encouraging beneficial fungi and bacteria which aid root uptake of water.

I did not look at the tutorial posted but you seem to have been pointed in the right direction with the instructions to determine the delivery pressure and volumes for that math is what makes the system work. All too many systems are done by "rule of thumb" when the math should have been worked out properly.

I do note that you do not have complete coverage in your head spacing. You need to have coverage from two directions wherever possible. Head to head coverage. So on the left half of the drawing, there are large parts in the center of the grass that do not have sufficient coverage. The grass on the right side has proper spacing. Space those heads closer together so that the circle from one head touches the next head. Easiest to arrange a tracing paper grid of the max spacing (15' triangles or whatever) and move it around to see what works best.

I'm not sure what you meant about mixing heads and the drip watering stages. Those stakes would be on a valve of their own for watering just the trees.

I'm trying to find trees that are not known for shallow roots and root suckers and honestly it hasnt been easy. I know I want a couple Fan-Tex Ash trees which seem to be ok but other trees I was considering, such as the Sissoo, are a no go and there aren't many options for the look I am going for...have to keep researching.

Thanks for the advice on the sprinklers, need to fine tune the left side a bit more like I said, seems like I need one more sprinkler there possibly to cover that area or maybe a different size for the middle left one to reach further out.

 

[HX_Guy]

Just my thoughts...

First off, the number of heads on a zone is worthless. like Janthony said, total # of gallons per zone is the info you need. Just because you have 12 heads per zone up front tells you nothing. how many gallon per minute do those heads use? My front yard is running a 5/8" meter on a 1" line and I think my biggest zone is around 30gpm. It hammers like a mother**** in the house when each zone shuts off and its only a matter of time before we have a major plumbing catastrophe in the house. Other problem is, is that when something using water in the house comes on like a toilet flushing, my pressure to my heads drop considerably and I have no pressure in the house when the system is running. To make a long story shorter, you need to focus more on how many gal per minute per zone.

Before you get crazy doing the design, you need to figure out what your water pressure is and how much flow you can get.

In all honesty, looking at your drawings, you're gonna have problems. In my opinion, since you have all those curves, go to smaller heads and use more of them, even if it means adding extra zones. spray nozzles are a little more forgiving than rotors when it comes to water volume and pressure. look at how the colors darken as they overlap. when the really dark areas look good, the really light areas are gonna look like ****. If you overwater to compensate, then the dark areas are gonna turn into the wetlands. "head to head" coverage is key.

As for the wire already being ran, that's no big issue. it can be extended, properly of course.

Remember this, the old adage of pay now or pay later comes into effect here. You can try and skimp on it as much as you can now, but you'll probably pay back more than what it would have costed to just do it right the first time down the road in repairs and re-working things. Might as well take care of it all now so you only have your yard torn up once rather than several times down the road.

So what causes the water hammer exactly? I had that at my old house and it was terrible...there was a faint noise as the system ran but when it shut off BANG! What do I need to do now to avoid that?

I asked a little earlier as well, but how do I go about figuring my gallons per minute per valve?

 

[Bama Rambler]

The best way to stop water hammer is to install an air chamber. The air will absorb the abrupt change in pressure so the pipes don't have to.

 

[stebs]

So what causes the water hammer exactly? I had that at my old house and it was terrible...there was a faint noise as the system ran but when it shut off BANG! What do I need to do now to avoid that?

I asked a little earlier as well, but how do I go about figuring my gallons per minute per valve?

Water hammer is caused when you have a very high flow velocity in the pipe that suddenly stops. To keep it in check, keep your pipe velocities down. Increasing pipe size helps. May have to add an expansion tank to help soften it.

As for the gallons per minute per valve, look up the flow rates for the nozzles you're using and add them up. So if you're using a .5 gpm nozzle in your heads and you have 10 of those on one valve, you have a zone at 5 gpm. Try and keep your zones under 15gpm. Your heads should say how much water they use. Just keep in mind that you may have to re-nozzle a head here or there to accomplish your goals, and the new nozzles should have a flow rate listed for them as well.

 

[HX_Guy]

I took a look at I actually have Hunter sprinklers, not Toro. The nozzles seem pretty efficient unless I'm not calculating this right. I did the figures for all 18 sprinklers with their respective arcs and have a total of 8.31 GPM @ 40 PSI for all 18 sprinklers. Does that sound right? That would mean I could run all 18 off of 1 valve if I wanted, though I would do 2 anyway.

http://www.hunterindustries.com/node/33106

I also took a look at my front sprinklers and I have 5.53 GPM between all 12 sprinklers on 1 valve.

 

[stebs]

That seems low but if that's what the math comes out to be, then that's what it is... Did you figure the correct radius as well?


Unless that pool is only 20' long, judging by your drawing, even at the max 6' spacing, its gonna take more than 18 to do it properly. going by your drawing, I would do at least 3 zones... I could be mis-interpreting your drawing though...