CLA Irrigation & Water Management Flashcards

What does 'ET' stand for in irrigation scheduling, and why is it important?

Answer: Evapotranspiration — the combined water loss from soil evaporation and plant transpiration

Evapotranspiration (ET) measures total water loss from the landscape and is the primary basis for calculating how much supplemental irrigation is needed.

Which irrigation head type delivers water directly to the root zone and is most efficient for water conservation?

Answer: Drip emitter

Drip emitters deliver water slowly at the root zone, minimizing evaporation and overspray losses and achieving application efficiencies of 90%+.

What is the purpose of a backflow preventer in a landscape irrigation system?

Answer: Prevent irrigation water from flowing back into the potable water supply

A backflow preventer is a plumbing device required by code to protect the drinking water supply from contamination by irrigation system water.

What does 'precipitation rate' mean for a sprinkler system, and in what unit is it expressed?

Answer: The rate at which water is applied to the landscape, expressed in inches per hour

Precipitation rate describes how quickly water accumulates on the soil surface, measured in inches per hour — it must match or be less than the soil infiltration rate to avoid runoff.

A 'smart' irrigation controller adjusts watering schedules based on:

Answer: Weather data or soil moisture sensors to match actual plant water needs

Smart controllers use real-time ET data, weather forecasts, or in-ground soil sensors to automatically adjust run times, reducing water waste.

What is the minimum recommended operating pressure for most standard pop-up rotary sprinkler heads?

Answer: 25–30 PSI

Most rotary sprinkler heads require 25–45 PSI to operate correctly; below 25 PSI, distribution uniformity degrades significantly.