I want to hit on an irrigation maintenance task that I feel is missed too often. I do not believe that I have ever met someone that enjoys wasting water, but not everyone wants to save water. Usually, these are seen as two sides of the same coin, but I believe they are different all together.
During our irrigation system maintenance last week, I found a head that was shooting into the road a little. This is an obvious example of wasting water. It was not wasting much, but a gallon is a gallon. I made a quick adjustment to the head and everything was right again. Did I save water? Not to me. I did not change the nozzle, or lower the run time. The same 245 gallons of water will come out of that head during its cycle tonight as it did last week. This is an example of the first step in saving water. Stop the waste, just like you would in LEAN management.
It is the next step that I want to hit on. While we were doing this same check, I found a zone that we had corrected the waste, but not saved the water. We have some areas that have heads on the dividing line from low maintenance areas to high maintenance areas. Typically, we do not irrigate our low maintenance turf. Most of these heads were changed to part circle last year, but a few mysteriously were not. Not only that, but the same nozzles were in the heads as the full circle heads on the zone. We forgot to change them. So we took the step to stop wasting water going into our low maintenance areas, but forgot to actually save the water. We dropped the nozzle down to match the precip rates, and when I ran the math on the projected water savings, I stopped dead in my tracks. We changed 5 nozzles from a 12 to an 8 (not perfect from a precip stance, but we lost coverage with #6 nozzles). This saved us 3.6 gpm/head X 5 heads. So we had a total savings of 18 gpm. I like to confirm this through flow meter data, but I have found the manufacturers data to be very accurate. This zone runs for 20 minutes, saving 360 gallons per cycle. With an average of 3 cycles a week over our 25 week irrigation season, this saves a staggering 27000 gallons of water!
If 5 simple nozzle changes can save that amount of water, what other potential areas are hiding right under our nose? We are starting to go through the system again looking for these areas where a nozzle is not right, or could be lowered. Cutting waste is an important first step in saving water, but you have to remember to actually save the water.