View Full Version : Watermain Size
04-14-2007, 12:59 PM
I have never done a sprinkler system before and I am trying to do a design for a sprinkler system and am stuck at the beginning. How do I figure out the watermain size without digging up my front yard?
04-14-2007, 02:24 PM
What size is your water meter? Where is it located?
04-14-2007, 04:48 PM
You have two considerations here. First the size of the meter and then the size of the line out of the meter. Older homes often had a 5/8" meter which is really too small for running much of a sprinkler system. It would also adversely affect the supply in the house if you were irrigating and trying to shower or wash clothes. When I installed my system years ago, I replaced the 5/8" meter with 1" meter and then ran a new 1" copper supply line out of that. The irrigation tees off about 4' after the meter and goes into a backflow preventer. There is a shut off valve at the tee so I can blow all of the water out in the fall. The sprinkler portion of the system goes from the backflow preventer across the yard about 30' to the side of the house where the valve box is located for the sprinklers. That line is 1-1/2" PVC. My home water is unaffected by sprinkler use, but I still normally irrigate in the wee hours of the morning to avoid as much evaporation as possible. I seriously doubt that the existing supply line will be satisfactory for both yard and domestic use.