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Starting Member


Wednesday, July 25th 2018, 12:49pm

Two Water Sources Operation for Sprinkler System

My Patio home is irrigated twice weekly by my HOA off of their water header. I have two zones and have located both valves. I want to tap into each zone downstream of the current control valve and add a new valve supplied from my water supply (with appropriate vacuum breaker) and control box. This will allow me to water at additional times. Is this possible or will the back pressure caused when I operate my valves damage the existing control valves and vise versa?


Active Member

Posts: 42

Location: Washinton


Wednesday, July 25th 2018, 8:35pm

I am guessing you want to use the same heads, just add an additional valve that you control?
Essentially what you would be doing is pressurizing the "Zone" side of a valve. When that happens the valve just does not operate, it stays sealed.
So no you will not hurt any control valves, you can T into the zone line anywhere and add another valve.
There might become an issue if one of the 2 valves fail, which may result in finger pointing and a contractor could push the issue with the HOA to possibly hold you liable.
Why not just have the HOA water more frequently?


Supreme Member

Posts: 5,331

Location: Metro NYC


Thursday, July 26th 2018, 6:23am

For your application, the backflow preventer must be an RPZ, and it's just too bad that they cost hundreds of dollars. Save your money and buy some hose-end sprinklers, if you must have watering beyond your allotment. Much more simple and economical.

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