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XII. Commercial LandscapeIrrigation Basics

Dave DeWolf – Consultant

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Lake County

Photo provided courtesy of Christie Cooper

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WATER EFFICIENT LANDSCAPE

(AKA)

WEL GARDEN

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WEL???

Photo provided courtesy of GardenSoft

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WEL - Benefits

oEnvironmentoWater and air qualityoScreens noises/unpleasant sightsoRefuge for people and wildlifeoModerates temperature

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WEL - ReduceoDaily & Seasonal peak water demandoGreen waste productionoRun-offoSoil erosionoHardscape damageo$$$$

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Lake County WEL

Photo provided courtesy of Christie Cooper

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What is a Water

Budget/Allocation?

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Landscape Water Budget

Most commonAmount of water required to maintain a healthy

landscape Landscape Size (sq/ft) Water requirements of plants. Inches of precipitation per sq/foot of soil.

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Landscape Water Budget

Result of a comprehensive Landscape/Irrigation Audit

Landscape observations Irrigation system evaluation Scientific calculations/Formulas

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ObservationsWater source

ControllersSensors

Plant Material/ConditionDensity

Micro Climate(s)Soil

Sprinklers/Application DevicesMaintenance/Condition Issues

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Water source

MetersPotable or ???

WellsPumps

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Controllers

Manual ValvesManually Programmed

Smart ControllersSensors

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Smart Water Irrigation Technologies(SWAT)

Climate Based Irrigation ControllersSoil Moisture Sensors

Weather Sensors

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Signal, Weather and Web Based Controllers

Photo by RainBird

Photo by WeatherTrak

Photo by Weathermatic

Photo by RainBird

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Soil Moisture Sensors

Photo courtesy of Irrometer

Photo courtesy of RainBird

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Tensiometers

Washington State UniversityCooperative Ext., Pub#PW0475 James, GJ Principles of Farm ISD

John Wiley, 1988

IPM News. Michigan State University, Pascal Nzokou

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Plant Material/Condition

What is being irrigated?How do the plants look?

What’s a WUCOLS?

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Density Factor

Photo provided courtesy of Dave DeWolf

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Low Density

Photos provided courtesy of GardenSoft

Medium Density

High Density

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Micro ClimateWhat is constantly influencing the landscape?

Photo provided courtesy of GardenSoft

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Soil

Soil Category / TextureSlope

CompactionStanding Water

23<Coarse Medium Fine >

Soil Texture

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Saturation

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Soil Moisture

Diagram provided by COMET UCAR

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Irrigation SchedulingSandy / Coarse

Faster applicationLonger durationSchedule more

frequentlyLoam / Medium

Moderate applicationSchedule less often

Clay / FineShorter durationsMultiple start/stop

times

Image provided by www.dripdepot.com

Coarse Medium Fine

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Sprinkler Type(s)How is the water getting to the plants?

Rotor

Spray

DripOR ???New Technology

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Maintenance and Condition Issues

Photos provided by Dave DeWolf

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Simple Fixes

Photos provided by Dave DeWolf

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Irrigation Terminology

EvapotranspirationIrrigation Efficiency

Distribution UniformityPrecipitation Rate

Hydro-Zone

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Water converted

from liquid to vapor

that does not pass

through the plant.

Evaporation

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TranspirationWater passes from

soil Into plant root hairs

Up through the stemExits leaves into the

airDiagram provided by courtesy of COMET UCAR

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EvapoTranspiration (ET)

Sum of water lost from Evaporation and water used

by plant Transpiration

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Reference ET (ETo)

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CIMIS – Station 13

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WEATHER Solar radiation, air temperature, relative humidity, and wind speed

SOIL FACTORSSoil texture, structure andchemistry

PLANT FACTORSPlant type, root depth, density, height, and stage of growth

If, ETo = 0.25 inches/day (for July 15, 1985) and, Kc = 0.55 (for an orange tree in July) then, ETc = ETo x Kc = 0.25 inches/day x 0.55 = 0.1375 or 0.14 inches/day.

Transpiration RateETo Climate Indicators

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Distribution Uniformity (DU)

Properly sized and matched sprinkler heads

Sprinkler spacing

Photo courtesy of El Dorado Irrigation District

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Precipitation Rate (PR)

Rate that irrigation water is applied per unit of time Measured in inches per hour (in./hr.)

Photo courtesy of the Center for Irrigation Technology at California State University, Fresno

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Irrigation Efficiency (IE)

Influenced by things you can and cannot control

Photo courtesy of Dave DeWolf

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Hydro-Zone

Photo courtesy of GardenSoft