Monthly Archives: September 2011


It seems simple enough. In order to have irrigation you need water.  In most places, water destined for irrigation MUST be isolated from the water we would normally drink.  To accomplish this neat little trick, most places in the country require some form of back-flow prevention. Something on the water supply that keeps the irrigation water (along with fertilizer, weed killers, dog poop, etc) from flowing backwards into the drinking water.

What does this have to do with making sure the water supply is on? Well, in most cases,  this back-flow thingee is also what’s used to turn off the water to the irrigation system. Most houses that are served by municipal water systems (a water meter) use a Pressure Vacuum Breaker or PVB for back-flow prevention. Below is a picture of a typical PVB.

Most PVBs look very similar to the ones above.   What’s nice about this picture is it shows how to turn the irrigation water off at the PVB.  Notice that there are 2 handles on each PVB. One set has yellow tips and one set has blue.  These are shut off valves or ball valves that can be used to shut off the water flow.  Also notice that both yellow tipped handles and one of the blue tipped handles are turned to line up with the direction of the pipe.  These 3 handles are in the ‘ON’ position.  The other blue handle (the lower one) is turned so that it is perpendicular to the pipe (crosses it).  This handle is in the ‘OFF’ position.

So here’s the situation, your grass looks dry and you wonder if your irrigation is running. You go to the timer and start a zone manually, the timer shows the zone is running but nothing is happening.  Somewhere around the house, normally next to the house you will find a PVB like the one shown above.  Look to see if someone (the lawn guy, your neighbor, the kids, whomever) turned off (crosses the pipe) one or both of valves (either one or both will shut off the water).  If so, turn it back on (in line with the pipe).  They are very hard to turn so you will probably need a pair of pliers of a wrench to turn it.  When you do, presto, the irrigation should start working.

I know it seems unlikely but I get calls from about 10 homeowners a year who can’t get their systems working because the water was turned off at the PVB and they didn’t know it. Of course this isn’t the only thing that can keep the system from running.  I plan to go over lots of other potential problems but the water supply shut off at the PVB  is the easiest to check and has the potential for the highest embarrassment factor.

Is it really broken?

Well that was short lived.  I do have a few things to say about solving problems with your irrigation system.  It may someday turn into an entire series of suggestions about how to diagnose problems and begin to tell the difference between what you (or your brother-in-law/neighbor/lawn guy) can fix on your own and what needs professional help to solve.

Most modern irrigation systems are surprisingly simple.  They consist of a water source (water meter, well, pump on a lake, etc), a timer or controller, some way to turn the water on and off and direct it to certain areas of the yard (valves and pipes) and sprinkler heads (sprays, rotors, drip, maxijets, bubblers, etc).  Get the water and get it to where it’s needed…simple, right?

Because I want to initially focus on troubleshooting let’s ignore the design and installation stuff and assume your have a ‘good’ irrigation system that’s just not working. Where do you start?  The easiest thing is to call me and I’ll come fix it, but that may not be the most cost effective thing to do.

Where I normally start by asking a couple of questions.  

  • Is the water on?
  • Is the timer on?
  • Is the rain sensor wet?


I don’t know how to blog.  I’m not completely sure what a blog is.  I originally thought it was some kind of ‘stream of consciousness’ narrative on the web that would be so entertaining that others surfing the web would  be drawn to read it.  Being a confirmed and dedicated curmudgeon, I’ve always wondered what could be so interesting about other people’s mindless blather.  I’m learning that blogs are a little more complex and nuanced, they can be anything from political mis-information to blatant commercialism. I don’t know where this missive will fit in the universe of blogation, but I intend to give it a try.

I have an obvious topic, a fancy appearance, several pages, and now for the hard part…those post things that make blogs blogs.