The Irrigation System: How it Works
I like to have the lawns at Springmoor aerated, and re-seeded by the first week of September. I can count on high germination rates mainly due to the lawn irrigation system. Now with the push of a few buttons, we can program when, how long, and how often we irrigate. The lawn irrigation system consists of the following components:
Backflow Preventers: These tie into the city water main, and prevent dirty water from entering our drinking water. Our larger North Campus has two, and the South Campus has one. These are brought out of storage in March, and put back in storage by December. They cannot be left installed permanently because they hold water, which would freeze and crack the units during a cold winter.
2 and 3 Inch Main Lines: These always have static water in them. They flow when the valves open up when they are programmed to do so. Both the North and South campus main lines form a loop around their prospective sides of the streets to ensure water is carried everywhere.
Valves: Sometimes called zones, Springmoor has over one hundred valves which tee off into 1-inch laterals. The valves are wired all the way back to a control box that is programmed to open and close the valve. So with all the miles of piping there are miles of underground wiring as well. Hot, common, and ground wiring is placed underneath the main lines. Someone digging is more apt to stop once they hit the main line, so the wiring is protected.
Controllers: These are the brains of the system, and as mentioned earlier, allow us to control the watering. We have twelve control boxes at Springmoor and they are programmed for different watering durations during different seasons. In the spring and fall, we water for about 1 inch a week, or each valve stays on for about ten minutes. During the summer, we water for 1 ½ inch a week to make up for evaporation. Valves can stay on as long as sixty minutes in some cases, but most average twenty. I program all watering to be done between midnight and 6 a.m.
When debris gets stuck in a valve, the diaphragm fails to close when the watering is finished. When sprinklers are seen operating during the late morning and afternoons, the Landscape Department should be notified. I test the system twice a month, but sometimes you can’t always catch a problem. Another reason for watering during off hours is lightening strikes. We have four controllers that go out of timing during electrical storms. Sometimes valves won’t open at all, in which case the solenoid (where the wiring leads to the valve) has gone bad and needs to be replaced. This problem is usually discovered during the bi-monthly irrigation audits.
1 Inch Lateral Lines: This is where water pressure is created by restricting water from the 2-3 inch main lines down to 1 inch. Lateral lines only have water in them when the valves are programmed to open. Water is further increased as the laterals lead off into the sprinkler heads.
Sprinkler Heads: Sprinkler heads come in three basic types: spray, rotor, and oscillating. Spray heads can be divided into full, three quarter, half, quarter, adjustable circle and split spray nozzles. All of these nozzle types can also have a ten-foot, twelve foot, and fifteen foot spread. Spray heads are used for smaller lawn areas. Split spray heads can be used for thin lawn strips such as along Springmoor drive. Rotors can cover lawn areas up to thirty feet in diameter, and more so on golf courses.
Oscillating sprinkler heads are a hybrid between spray and rotor heads, as they cover medium sized lawn areas of twelve to eighteen feet in width. They actually rotate a spray in full, three quarter, half, and quarter circles. Sprinkler heads can become plugged up with dirt and grass, and must be monitored to see that they are operating efficiently, or haven’t been knocked out of adjustment.
That’s our irrigation system, its basic components and how it works. I am sure glad to have it!
Crape Myrtles and Rose of Sharon will be in their final bloom period but shrubs such as Abelia, and Butterfly Bush will bloom until frost. Look for Encore Azaleas to bloom for the second time this year, and they bloom just as well as they did back in the spring. You might see an early Sasanqua Camellia in late September, but they usually bloom in October.
- Aerate and Seed fescue lawns
- Apply 10 10 10 or 8 8 8 to your fall vegetable gardens
- Apply BT or Dipel to your fall crops. This stuff works great in combating white cabbage butterfly worms. Plus, it’s non–toxic to us. It’s bacteria that only target the worm.
- Plan ahead for your winter annuals- we install ours at Springmoor the first week or so in October.
- Cover Crop If you have given up vegetable gardening for the winter, it’s a good idea clean up your garden and add red top clover, annual rye, or just mulch with wheat straw.