C27 License - C-27 Landscaping Contractor License Irrigation Systems Installation Questions and Answers

Question 1

A client notices consistently dry spots in their lawn despite the irrigation system running regularly.
The system has mixed types of sprinkler heads (e.g., full-circle, half-circle, and quarter-circle) within the same zone.
What is the MOST likely cause of the uneven watering?

Accepted Answer

The system lacks matched precipitation rates (MPR).

Answer

The backflow preventer is malfunctioning.

Answer

The main water pressure to the property is too low.

Answer

The controller is programmed for the wrong season.

Question 2

According to California regulations, what is the minimum requirement for backflow prevention on a new irrigation system connected to a public water supply?

Accepted Answer

A reduced pressure principle (RP) backflow prevention assembly.

Answer

An atmospheric vacuum breaker (AVB) on each valve.

Answer

A double-check valve assembly (DCVA) at the point of connection.

Answer

Annual inspection by a certified tester is sufficient.

Question 3

Which of the following factors is the PRIMARY determinant of friction loss in an irrigation pipe?

Accepted Answer

The velocity and volume of water flow.

Answer

The brand of the PVC pipe.

Answer

The time of day the system operates.

Answer

The elevation change of the landscape.

Question 4

A landscape contractor is installing an irrigation system in a non-turf area on a slope greater than 25%. Which type of irrigation is required to maximize water infiltration and prevent runoff?

Accepted Answer

Drip irrigation or other low-volume technology.

Answer

Impact-drive rotary sprinklers.

Answer

High-efficiency spray nozzles.

Answer

A hose-end sprinkler moved manually.

Question 5

If an automatic irrigation valve fails to shut off after a watering cycle, what is the most common component to investigate first?

Accepted Answer

A faulty solenoid or debris in the valve diaphragm.

Answer

A clogged sprinkler nozzle.

Answer

The master valve.

Answer

A tripped circuit breaker at the controller.

Question 6

What is the primary purpose of 'hydrozoning' in irrigation system design?

Accepted Answer

To group plants with similar water requirements onto the same valve circuit.

Answer

To group plants based on their mature height.

Answer

To ensure all pipes used are the same diameter.

Answer

To alternate watering days for different sections of the landscape.

A client notices consistently dry spots in their lawn despite the irrigation system running regularly.The system has mixed types of sprinkler heads (e.g., full-circle, half-circle, and quarter-circle) within the same zone.What is the MOST likely cause of the uneven watering?

A client notices consistently dry spots in their lawn despite the irrigation system running regularly.
The system has mixed types of sprinkler heads (e.g., full-circle, half-circle, and quarter-circle) within the same zone.
What is the MOST likely cause of the uneven watering?