An automated irrigation system is the best way to keep your lawn and landscape looking beautiful and healthy. When well-planned, properly programmed and using the right components, a sprinkler system can be very water efficient. This can have a beneficial impact on your budget — according to the TCEQ (Texas Commission on Environmental Quality), lawn and gardening watering makes up 30-50 percent of total household water use.
An efficient system consists of the following:
Your irrigation areas should be separated into hydro-zones or sections where the plants need approximately the same amount of water. The zone size depends on the available flow rate and pressure available to the irrigation system, as well as the type of sprinkler used. Improper planning means some plant materials will be overwatered, while others will be underwatered in the same zone. Different watering zones must be created for:
- Sunny and shady sections.
- Areas with different wind exposure.
- Drip irrigation.
- Plants with different water requirements (e.g. lawns and shrubs) or soil conditions.
- Slopes, or different sections of slopes.
Proper Sprinkler Type and Layout
The different sprinkler types for lawns include pop-up fixed spray heads, rotors, and rotary or rotator nozzles, all with a wide range of throw distances and nozzles. Your choice of sprinklers and nozzles depends on your water pressure, zone shapes (e.g. long and narrow, curved or odd-shaped), and zone sizes.
Sprinkler heads should be placed as equidistantly as possible in each zone to achieve what is known as “head-to-head” coverage. This is where sprays overlap — each sprinkler throws water all the way to the next one in each direction so there are no dry spots.
Sprinklers should not spray water onto sidewalks, fences, driveways, and the sides of homes. This wastes water and creates slipping hazards. Appropriate sprinklers for the zone, along with properly adjusted nozzles should prevent this from occurring.
Spray heads, rotors, rotator nozzles and drip irrigation should never be combined in the same hydro-zone. Each of these has a different water application rate, which would cause wet or dry spots and waste large amounts of water if in the same zone. In Texas, the TCEQ has mandated that all sprinklers in a zone must have matched precipitation rates.
Wi-Fi weather-based controllers are among the smartest controllers available. They receive updated real-time weather information from online weather services that automatically adjust their irrigation schedules to meet the water needs of on-site plants. According to the Environmental Protection Agency (EPA), weather-based controllers can save an average home thousands of gallons of water a year when replacing a standard clock timer.
There are other types of weather-based controllers:
- Historic ET (evapotranspiration) controllers.
- Historic ET controllers with a sensor (temperature or solar radiation).
- Sensor-based controllers (mini-weather stations, or weather sensors monitoring temperature, rainfall, solar radiation, or soil moisture).
There’s also a soil sensor-based controller that uses sensors to measure the moisture content of the soil to determine the watering schedule.
Older scheduling controllers can be upgraded to “smart” with add-on sensors such as rain, wind, or freeze sensors that interrupt the irrigation cycle as needed.
Other efficiencies offered by irrigation controllers:
- Seasonal adjust feature on many controllers that reduces or increases run times in all zones based on a percentage of programmed time.
- Ability to run different schedules for zones to account for plant type, sprinkler type, and landscape conditions. Applying the correct amount of water for each zone is crucial, as too much water encourages fungal diseases. Soil that’s too moist also creates an environment ideal for white grubs to lay their eggs. Underwatering doesn’t give grass the opportunity to develop deep, strong roots to stay healthy. It’s then vulnerable to disease and pests that do damage in dryer conditions, such as sod webworms and chinch bugs.
- Some controllers have a “cycle and soak” setting where you can water in multiple shorter cycles. Even if your controller doesn’t have this setting, you can set up the total run time for each zone and divide it into several cycles. This prevents runoff by allowing the water to soak into the soil, creating deep, healthy plant roots.
- Ability to choose the time of day to irrigate. It’s better to run your system early in the morning when the temperatures are cooler and there’s little or no wind. Less water is lost due to evaporation, and water doesn’t sit on the grass all night. Lawns left wet overnight are more prone to disease such as leaf spot and pythium blight.
In Texas all new automated systems or replacement controllers must include a rain sensor or other shutoff device approved by the TCEQ that’s “designed to inhibit or interrupt operation of the irrigation system during periods of moisture or rainfall.” A rain sensor is valuable even to weather-based smart controllers using local weather data to adjust schedules. The rain sensor, being on-site, can give more timely and accurate information to the controller than the weather station can.
Often a rain sensor is combined with a freeze sensor. In some Texas cities both are mandatory.
Replacing traditional spray irrigation with drip irrigation for planting beds, and tree and shrub areas can greatly increase water efficiency. Drip irrigation can reduce water loss by 60 percent or more compared to spray irrigation because it applies water just where it’s needed. There’s little chance of waste due to runoff or evaporation, and the minimal water contact with plant leaves reduces the possibility of disease.
Regular Maintenance and Inspections
An efficient system is regularly inspected and maintained. Broken components or other equipment problems waste water and increase your water bill. For example, an ignored system leak, even one as small as 1/32nd of an inch in diameter (about the thickness of a dime) can waste about 6,300 gallons of water a month (EPA). A neglected broken sprinkler head can waste 480 gallons a month (Austin Water).
During inspections look for the following equipment problems that are wasting water or not distributing it evenly:
- Broken sprinkler heads.
- Broken or clogged nozzles.
- Spray heads misting due to high pressure.
- Wrong sprinkler head(s) or nozzle(s).
- Heads not popping up or spraying very far due to low pressure.
- Heads too low.
- Tilted heads.
- Obstructed heads.
- Mis-aligned heads.
- Leaking valves.
- Leaking pipes.
- Low head drainage
By keeping your system in peak condition, you’ll save yourself additional time and labor maintaining the plant life on your property. Your grass will put down deep, healthy roots that will help it better tolerate drought conditions and cold weather, and be more resistant to weeds, pests, and disease.
Benefits to Your Property and the Environment
There are also benefits to your property and the environment when maintaining an efficient irrigation system:
- Prevention of runoff. Runoff occurs when water is applied too rapidly, or in too great an amount for the soil to absorb. It carries soil, pesticides, and fertilizers from the landscape into the street, and eventually ends up in lakes, rivers, and streams via storm sewers. It can also flood sidewalks and driveways, becoming a slipping hazard, and accelerating the deterioration of asphalt surfaces.
- Prevention of overspray. Overspray is water that lands beyond the grass area. It can run into the street and storm sewers as well, carrying debris, oil, and other pollutants along the same path as runoff into local waterways. As well as being a safety hazard by flooding areas around the home, it can cause damage to fences, sidewalks, siding, patios, and garden structures.
- Prevention of overwatering. Overwatering leaches fertilizers and pesticides into the groundwater and contaminates it. It can also result in runoff.
To keep your sprinkler system in top running condition, call the experts at Smart Earth Sprinklers at (512) 694-1147 or contact us online.