CPH CPH Irrigation and Water Management 2 — Questions and Answers
Question 1: What is the primary advantage of a 'smart' or weather-based irrigation controller over a standard timer?
- It requires no electrical power source to operate
- It automatically adjusts watering schedules based on real-time or historical weather data (Correct answer)
- It completely eliminates the need for a backflow prevention device
- It costs significantly less than conventional programmable timers
Correct answer: It automatically adjusts watering schedules based on real-time or historical weather data
Smart controllers use ET data or on-site weather sensors to automatically adjust runtimes, preventing overwatering and conserving water without manual reprogramming.
Question 2: What causes 'water hammer' in an irrigation system?
- Elevated water pH corroding pipe walls
- Sudden changes in water velocity creating damaging pressure surges (Correct answer)
- Clogged sprinkler nozzles restricting normal flow
- Operating the system below the recommended minimum pressure
Correct answer: Sudden changes in water velocity creating damaging pressure surges
Water hammer occurs when rapidly closing valves cause sudden velocity changes that produce destructive pressure surges, potentially cracking pipes and fittings.
Question 3: What is the typical minimum operating pressure required for most standard pop-up spray heads to function correctly?
- 10 PSI
- 15 PSI
- 30 PSI (Correct answer)
- 60 PSI
Correct answer: 30 PSI
Most pop-up spray heads are engineered to perform at a minimum of 30 PSI; operating below this threshold reduces throw radius and distribution uniformity.
Question 4: The application rate of drip emitters is most directly determined by:
- The diameter of the supply pipe feeding the drip line
- The emitter's rated flow rate in gallons per hour and the spacing between emitters (Correct answer)
- The texture and water-holding capacity of the surrounding soil
- The depth of organic mulch applied over the drip line
Correct answer: The emitter's rated flow rate in gallons per hour and the spacing between emitters
Application rate depends on each emitter's rated flow (GPH) and the spacing between emitters; both must be matched to soil infiltration rate to prevent runoff.
Question 5: The purpose of 'zoning' in irrigation system design is to:
- Satisfy local zoning and permitting requirements for water use
- Group plants with similar water requirements into the same irrigation circuit (Correct answer)
- Divide the property into equal-area sections for efficient coverage
- Alternate drip and sprinkler circuits on separate days to reduce pressure
Correct answer: Group plants with similar water requirements into the same irrigation circuit
Zoning groups plants with similar water needs into the same circuit so each zone receives the precise amount of water its plants require.
Question 6: What is 'cycle and soak' irrigation scheduling?
- Alternating drip and overhead sprinkler zones within a single program
- Running multiple short irrigation cycles with rest periods between them to improve soil infiltration (Correct answer)
- Cycling through all zones once per day followed by a deep soaking every week
- Manually soaking new transplants daily for the first month after installation
Correct answer: Running multiple short irrigation cycles with rest periods between them to improve soil infiltration
Cycle and soak splits a full irrigation run into two or more shorter cycles separated by rest periods, allowing water to percolate into the soil and reducing surface runoff.
CPH CPH Irrigation and Water Management 2
What is the primary advantage of a 'smart' or weather-based irrigation controller over a standard timer?