CSLB C-27 Landscaping ContractorIrrigation SystemsHard
A landscape contractor is retrofitting an older irrigation system with more efficient components. The existing system uses standard spray heads, resulting in significant overspray onto paved areas. To achieve the greatest water savings and reduce overspray in an irregularly shaped turf area, which type of emission device is the most appropriate upgrade?
- AFixed-pattern spray nozzles.
- BHigh-pressure impact rotors.
- CMulti-stream rotating nozzles.
- DBubblers with adjustable flow.
Show answer & explanationAnswer & explanation
Correct answer: C. Multi-stream rotating nozzles.
Multi-stream rotating nozzles (often called rotary nozzles) are designed to apply water more slowly and uniformly than traditional spray heads, typically at a lower precipitation rate. Their multiple streams and slower rotation reduce misting, are more wind-resistant, and allow for more precise edge control, significantly reducing overspray and leading to greater water savings, especially in irregularly shaped areas where precision is key.
Why the other options are wrong
- A. Fixed-pattern spray nozzles are what the existing system likely uses, and they are known for higher precipitation rates and overspray, especially in irregular shapes.
- B. High-pressure impact rotors are designed for large areas and often have high flow rates and can be prone to overspray if not carefully managed.
- D. Bubblers are designed for concentrated watering of individual plants or small areas, not for broad turf coverage.
Multi-stream Rotating Nozzles
Emission devices that deliver water in multiple, rotating streams, providing a lower precipitation rate and better uniformity than traditional spray nozzles.
- Reduces runoff and improves water absorption, especially on slopes and clay soils.
- Greater wind resistance and reduced misting compared to standard sprays.
- Excellent for retrofitting older systems to improve water efficiency and reduce overspray.
Memory trick: Rotating streams gently land, saving water across the land.