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Irrigation systems - Terms to know

Automatic controller 
A timing device that sends an electric signal to valves, telling them when to open and close as per a set irrigation schedule.

IA Certified Irrigation Auditor
An Irrigation Association (IA) Certified Landscape Irrigation Auditor (CLIA) analyzes landscape irrigation water use. These auditors collect site data, make maintenance recommendations and perform water audits. Through their analytical work at the site, these irrigation professionals develop monthly irrigation base schedules. Certification requires an examination and an Irrigation Association approved preparatory course.

Drip irrigation
Any irrigation system that applies water to the soil very slowly. Currently, this technology is the most efficient from a water and energy use standpoint.

Evapotranspiration (ET)
The loss of moisture from vegetation into the air. ET refers to a combination of the evaporation of water from Earth's surfaces and transpiration, the evaporation of water from the surfaces of plants. The deficit between water available and water needed by a plant is the amount of water you need to add by irrigation.

Flow sensor
Detects the amount of water moving through an irrigation system. In centrally controlled systems, the flow Sensor can detect leaks or possible breaks in the system.

Head to head coverage
The spacing of sprinkler heads so that each sprinkler throws water to the next sprinkler head. Simply put, where the spray pattern from one head ends there should be another head. That spray pattern should reach back to head one, so there is overlap in spray patterns from one head to the next.

An irrigation area where all the watering influences are similar. Factors to be considered when setting up hydrozones would be plant types, sprinkler precipitation rates, wind, soil type and slope.

Master valve
The main valve for the irrigation system. When this valve is closed water will not be supplied to the irrigation system.

Match precipitation rates
In your irrigation system, the flow rates have to be reduced in the quarter-circle spray heads in the corners and the half-circle spray heads to match the amount of water being put down by the full-circle heads. Simply put, this means corner nozzles should have a flow rate one quarter that of full circles. Half circles would need a flow rate double the quarter circle or half the full circle in order to run the same length of time and apply the same volume of water.

Rain switch/sensor
This switch prevents irrigation during and, sometimes after, precipitation.

Soil moisture sensor
Placing this sensor in the ground lets you know when water is needed at depth.

Irrigation system types

Central Control System
The most advanced type of irrigation system. It uses real-time weather data to calculate the watering needs of your landscape. The system is remotely monitored and adjusted and automatically detects and controls leaks. More than 25 per cent of Calgary's irrigated parks use this type of system. Though an up-front financial investment, these systems save 25 to 50 per cent in water use and are about one-third less costly to operate than manual systems.

Standard Automatic System
Operates similar to a clock radio. The start time and length of the watering operation is programmed and it runs this program, regardless of weather or damage. Running this system is less costly than a manual one but is less efficient and more money will be spent on water than with a Central Control System.

Manual Pop-up System 
A number of underground sprinklers connected to manual valves. Someone goes on site and turns the valves on and off to start and stop watering. They are susceptible to running too long and wasting water.

Download a list ofIn-ground Irrigation Systems.