April 1, 2012
I'm Dan Hounsell, editor of Maintenance Solutions magazine. Today's topic is, water-efficient irrigation.
The primary goal in irrigation for institutional and commercial facilities is reducing use of potable water in landscapes — ideally, by about 50 percent from established baselines. Inefficient irrigation is a big culprit in water waste. Most irrigation systems installed more than five years ago operate at less than 45 percent efficiency. WaterSense guidelines from the U.S. Environmental Protection Agency (EPA) require a minimum of 70 percent efficiency.
The first step in improving efficiency is to conduct a water audit. Call a licensed landscape or irrigation contractor who can pinpoint waste and recommend strategies for savings. These strategies likely will include installing flow meters to monitor and control water use. Most systems have automatic shutoff features, so if a line happens to break, water flow will cease.
From an efficiency standpoint, drip-irrigation systems are an excellent option. The lines run about 2 inches below the surface, and water drips directly into the roots of plants. Drip-irrigation systems have an efficiency of 95 percent, compared to 50-65 percent efficiency of a traditional, overhead system.
If an existing irrigation system requires optimizing, managers can use several strategies. One strategy involves replacing older irrigation heads. Newer models can greatly improve the accuracy of water disbursement. These models irrigate turf and plants based on the individual amounts required, rather than overwatering in some areas and under-watering in others.
Managers also can have irrigation systems designed and installed so trees, shrubs, and ground-cover plants are in separate zones. As plants become established, the system adjusts or discontinues watering by zone.