Last week, Lenny Theobald of Rain Bird gave a talk about efficient irrigation during customer appreciation day at Shemin Landscape Supply in Morrisville, NC.
I’m all about efficiency in the landscape. Water is critical but so often improperly used, wasting this precious resource and wasting money. I’ve posted a couple of articles on proper watering, see here and here.
Rain Bird emphasizes the Intelligent Use of Water (click for their publication). Lenny focused on some of the most efficient products Rain Bird recommends.
I’m most excited about their new Copper Shield drip lines. These drip lines are specially designed to be used for subsurface drip irrigation. One of the biggest problems with drip irrigation underground is that roots can clog up the in-line emitters. Root inhibiting chemicals can be used in the lines, but these have copper inserts at each emitter that naturally inhibits roots with a localized effect. It’s been tested for 15 years and is expected to have a 16 year lifespan. Subsurface drip is perfect for devil’s strips (the area between the curb and sidewalk) and for other narrow areas of turf where overspray is hard to reduce with overhead irrigation. I suppose it could also be used for groundcover plantings as well. I’d love to find someone in the Triangle, NC area who’d like to give this product a shot. Correct installation is critical, spacing of lines and emitters depends on the type of soil.
Have you ever seen soil erosion or water leaking around a head on a system, especially at low areas? Water will drain out of the lowest irrigation head due to simple gravity. This water loss is a complete waste that can increase the chance of water hammer in lines and means the zone needs to run longer to recharge the empty pipes and irrigate the area. Check valves can keep this from happening. Some municipalities require check valves at heads near curbs and sidewalks–it’s a good idea to use them to save water.
Did you know that sprinkler heads run best at certain water pressures? Too much pressure results in tiny water droplets that can easily evaporate and drift. There are sprinkler heads with pressure regulating mechanisms that help make the heads more efficient–most can save you 50% more water if the pressure is too high.
More savings can be found with nozzles that allow better close in watering at the heads. Have you ever noticed that grass close to the head doesn’t seem to get much water? It’s easy to just make that zone run longer, but then you are overwatering other areas and wasting water. Using the most efficient nozzles can save up to 30% more water.
There’s a lot that can be done with proper scheduling of irrigation systems to save water. Lenny said that, on average, most irrigation systems are adjusted 1.5 times per year. Usually systems are set for the highest water demands of the year. Or maybe they are set for that new landscape installation and never adjusted. Both mean a lot of wasted water. Ideally, systems should be adjusted weekly weekly, or at least monthly. Minimally, systems should have rain sensors to keep them from running when it’s rained a predetermined amount. Rain Bird has a soil sensor that should be even better than a rain sensor. Both types of sensors will shut off the system until enough of the water disappears (from the rain sensor or the soil). Sensors can be used on any system.
Rain Bird finally has a smart controller I can recommend. Until now, I’ve only recommended the Toro Intelli-sense controller which uses downloaded ET data to schedule waterings. Other smart controllers are available, but I haven’t liked the on-site weather stations. Rain Bird has a rain gauge that calculates how much and how fast rain falls. That data is combined with historical weather data for your area to schedule watering more efficiently. Smart controllers have been shown to save at least 35% more water than regular controllers.
I worked with clients that had a new irrigation system installed. The couple was expecting a child in August. The system went in in July with a smart controller installed. When I took a look at the system in September, the watering schedule had adjusted itself to water no more than once or twice a week (in summer it had been watering 3 times a week). While adjusting to new baby schedules, my clients had no time to adjust irrigation schedules. If they had installed a old style controller, they’d have wasted a lot of water and money!
Now, all of these water saving products will increase the cost of your system. But remember, a cheap system will cost you a lot of money over time. Most of these extra costs will be made up in the first couple of years in water savings. Also, if you have an existing system, it can be updated with new technology. Whether you are installing a new system or upgrading an old one be sure to find an irrigation contractor that is familiar with these products.
If you make sure your irrigation system is as efficient as possible there is no doubt you’ll save water and money. Plus, you’ll have a healthier landscape better able to withstand drought if the water needs to be turned off. Our most visible water use (and water waste) tends to be in our irrigation systems. It’s often the first water use attacked during droughts. If we can all save water, maybe we can keep those attacks at bay.