Drought in Texas? Who could have seen that coming? Seriously, various degrees of drought are a fact of life for those of us lucky enough to live in Texas. And while we can’t make it rain, there are sound irrigation practices that will help conserve water, an increasingly precious resource.
Environmentally-conscious (and cost-conscious) homeowners are tending more and more to smart controllers for their irrigation systems. Unlike the old-school irrigation clocks that regulate the start time and duration of watering, smart controllers do so much more. These devices are quite remarkable.
According to the Irrigation Association “smart controllers leverage the latest technology to ensure your landscape receives the precise amount of water based on a number of factors including plant material, soil type, slope, sprinkler type, temperature, humidity and rainfall.” A smart controller will automatically adjust the watering based on the temperature and rainfall; less water as the weather cools and more water on hotter, drier days. Some smart controllers will use historical weather data for specific areas, often by zip code, which require manual adjustment during unusual weather patterns. Others use their own weather stations to determine real-time conditions. Still others come equipped with their own rain and soil moisture sensors to prevent unnecessary watering.
Many of these controllers can be regulated and adjusted remotely with a cell phone or tablet app. These user-friendly apps will allow you to control up to eight independent water zones (you can even name each zone and have an image of it on your phone). These apps will also record watering cycles that adjust to real-time conditions, and will send alerts for such events as freeze warnings, delayed watering, and shorted valve switch (solenoid). And they are amazingly easy to program. Rain Bird has a user tutorial at http://wifi.rainbird.com/how-it-works/.
Smart controllers, though an important part of water management, don’t generate maximum savings all on their own. They are best paired with an efficient and properly maintained irrigation system.
Water Pressure and Nozzle Efficiency
Did you know that water pressure makes a profound difference in the efficiency of your irrigation system?
High water pressure atomizes the water and the more water is atomized, the lighter it becomes so more of the spray will drift and evaporate instead of being absorbed where you need it. This misting of the water can cause up to an estimated 25% water loss.
Misting is great for the patio on those hot, humid days and nights but when you’re watering your lawn and ornamentals, you want nozzles that will deliver large water droplets that cut through the wind and deliver the water to the target zone.
The high efficiency systems use lower water pressure that deliver streams of water, not mists. Water conservation is significantly enhanced with high-efficiency nozzles.
A flow sensor measures the volume of water flowing through the irrigation system, typically in gallons per minute. Too much or too little flow of water will alert you to a problem in the system such as broken pipes or valves, broken or clogged sprinkler heads, or underground leaks.
Some flow sensors will send the flow data to a central or stand-alone controller system. When low flow or excess flow conditions are detected, the controller will quarantine and shut down the problem area and continue to irrigate the areas that are not affected.
You don’t even necessarily have to manually enter flow rate data into the controller; the controller will learn it.
Check vales prevent drainage from the line once the system has shut off. Drainage can occur through the sprinkler head at a lower elevation than the zone valve in a sloped landscape. This drainage not only wastes water, it can also cause runoff and erosion of the area. Some sprinklers have built-in check valves.
Best Time to Water
Hours of the day during which watering is permitted varies according to local regulation, but many of the Austin area water restriction regulations do not allow watering during the hours of 10:00 a.m. to 7:00 p.m. This is not a bad thing.
Watering during the day is not recommended because evaporation or poor root absorption can result. Watering in the evening is not ideal as the water can cling to the blades of the grass overnight, promoting fungus and other lawn diseases.
Early morning is the best time to water. The air is cooler and there are usually not high winds to disrupt the spray pattern. Watering between the hours of 2:30 a.m. and 8:00 a.m. allows for maximum absorption and root penetration. Multiple start times, often referred to as “cycle and soak” allows the water to penetrate hard soil rather than run off.
Cycle and Soak
According to Dr. Richard White, a turfgrass management scientist in College Station of Texas A&M University AgriLife Research, most urban areas in Texas are clay-textured soils. He says that while these soils are fertile, they have very small pore spaces and are slow to accept water, with an infiltration rate of well below one-tenth of an inch per hour across most of the state.
Dr. White says that it’s not unusual to lose 30 to 40 percent of the water you apply. “It will end up going across the curb, down the gutter and into the storm drain.”
The AgriLife Research & Extension Center research recommends the cycle and soak method of irrigation, saying that it will “drastically reduce and in some cases eliminate runoff”.
In this method, the water is applied multiple times with a waiting period of between 30 and 60 minutes between applications to allow the water to soak into the soil.
The first watering cycle breaks the soil’s surface tension and saturates the top layer, allowing the second watering cycle to more efficiently infiltrate the soil. A third and even a fourth cycle is suggested for sloped landscapes or if runoff occurs after the sprinklers have run for just a few minutes.
Quite apart from water conservation and cost savings benefits of reducing or eliminating runoff, there is also a health benefit to this method of irrigation. Runoff from residences can contain concentrations of nitrogen or phosphorus that are swept into the municipal drain system. Runoff from residences that are home to, for instance, multiple pets can also contain fecal coliforms that also enter the municipality’s sewage system.
Cycle and soak captures more water in the soil and promotes deeper roots and healthier greenery.
There are many other devices, tips, and methods of irrigation that will increase the efficiency of your irrigation system to conserve water, give you a thriving landscape, and save you money. We will examine some of them in further articles.
Protect your investment in your home and landscape. Call Smart Earth Sprinklers at (512) 694-1147 for the very best in sprinkler system maintenance and repair.