SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I only see one question about the irrigation meter. You would need to get a rough idea of your GPM and watering time for your zones and do the math of cost vs savings.

Anyway, plan to winterize the system. It only takes one cold night to burst an above ground pipe or PVB. Your static pressure seems really good. Mine is only about 50.

Your lot is very small. My lot is 75' x 100'. For comparison, I have my zones designed to use about 8GPM. A 1" copper pipe from the street (about 45ft) into a 5/8" Badger water meter. From there it goes to my 1" Sched 40 PVC for another 30ft, through the PVB and into my 1" Sched 40 main manifold. 1" zone valves feed 1" poly laterals. I am using Hunter MP2000, Hunter MP3000, Hunter PS Ultra 12A's for the main yard and Hunter Side Strip nozzles for the sidewalk strips. All of them cover very well. The 12A's throw down so much water I have to do a very short run time on them.

I have 7 zones, but two of them are just to do the sidewalk strip, one on each side of the driveway. Since I run those two zones at the same time, I run at as if I have 6 zones. I think you could easily cover your property with that number of zones.

I would suggest using 1" instead of the 3/4" for your main trunks. You never know what the future holds for your water pressure. If they build in your area and tap into your water main you could see that pressure drop.

On the subject of the meter, it's not just the cost of installing. You have to get the details from YOUR water company. Most usually have a minimum charge per month for each meter. I know our city it's something like $8/month, and that pays for the 1st 5000 gallons of water. But if I only use 1000 gallons in a month, I'm still charged the $8 minimum.

I know that in my case, when I ran the numbers, I found that the saving in sewer charges during the summer pretty much matched the cost of the minimum during the winter. (I also later found out that you can get the service for the 2nd meter turned off during the winter months).


On your choise of main line pipe, I would recommend you upside to 1" PVC. There isn't much of a price difference between 1/2", 3/4", and 1" PVC pipe and fittings. Yet a 1" pipe has twice the capacity of 3/4" (or only 1/4 the pressure losses). You don't see a (relatively) major difference in prices until you get into the 1-1/4" stuff.

I'd also recommend you look more into 10"-12" deep for burying the pipe. The deeper, the better it's protected (from both unexpected cold temperatures, but also from any "heavy" equipement that might ever come accross your yard.

Better yet, I'd suggest that you spend this fall and winter reading over the web site Irrigation tutorials.com. It's loaded with lots of good information, and you've got the time to try to digest it.

The closer you can tie in after the meter, the less of an impact it will have on the water supply for the house. If you can find out your make and model of your meter you may be able to find the flow rate and psi drop for it online. Mine is a 5/8" Badger rated at 15GPM continuous and 25GPM peak. At 7.5GPM it is rated for a 1PSI drop in pressure. Having two meters would definatly decrease the PSI drop but the question is... is it enough of a drop to justify the price? Probably not if you design your system properly and take a conservative approach. Just by going from 3/4" to 1" pipe for your main line, valves, and manifold you can easily offset that.

Definitely read irrigationtutorials.com over and over until you understand everything he is talking about. LOTS of good information there.

I rented a 1.5" wide by 12" deep trencher from Home Depot for the day. It was a BEAST to run. Basically, it was a large diameter disk spun by a gas engine, I think it was called Ground Saw by EZ Trench. Nearly impossible to make curving trenches with unless you're strong enough to man handle it.

By far running the trencher (or should I say dragging it through the dirt) was the most tiring. It went great through soil but clay and hard packed dirt was brutal and slow. I wanted to use a pipe puller but I have no experience running them so I opted for the trencher. If your soil has large chunks of wood or concrete, plan on stopping often to clear out the cutting disk.

Quoted from "ReddHead"

I rented a 1.5" wide by 12" deep trencher from Home Depot for the day. It was a BEAST to run

I rented Ditch Witch. It goes 4" wide and 24" deep. We did like close to 600' of trenches in 4 hours. You can only go in straight lines.

Whether or not you need the outside meter depends on your water
department. I have an outside meter for the irrigation and the outside
spigots. There is no monthly charge for the meter only the cost of
installation. We pay big water bills in my area and the majority of the
charge is for the sewer charge, so with the outside meter they subtract
the sewer charge from the second meter. I couldn't afford to not have
one but for you it depends on your jurisdiction.
The 10-12 gpm that
you have with 70 psi is pretty good. You will want to leave a few gpm's
for the residual gallonage. About 3 gpm's is good to leave some room so
that leaves about 7-9 gpm's for the irrigation system. You will need to
check out the heads/nozzles that you plan on using to find the different
gallonage usage for a given nozzle/pressure. Most rotary type heads
like Hunter or Rainbird come with a chart that shows what the gallonage
output will be for the different nozzle types at a given psi, as well as
the coverage area. I have similar specs to yours as far as my gallonage
and psi service to my house. I have 5 or 6 rotary heads per zone for my
lawn zones as well as several spray zones and drip zones for flower
beds. Some people use the same nozzle type in all of their rotary heads.
I find that the best way to set up the rotary heads is to use as an
example a 2 gpm nozzle in a full circle pattern, a 1gpm nozzle in a 180
degree pattern, and a .5 gpm nozzle in a 90 degree pattern. This leaves a
little headroom for changing your nozzles either up or down. From there
you
can adjust according to soil type and grade etc. You should definitely
use 1" pipe. You can use a Ditch Witch or a trencher it is up to you. As
some have said a large trencher can be a bear to use. I used a large
trencher only because I was also running underground electrical runs to my garage and also to a post light. Also the lawn was in tough shape anyway so I had to reseed and repair the whole thing anyway. If I didn't have to do that I would have rented the
Ditch Witch. The Ditch Witch does a lot less damage to the lawn.