1. Break !!!
Break Time
Cornell Short Course
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2. Proper watering techniques
Poor Plant Health
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3. Root Depth & Soil Type
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4. Active Root Zone
The depth of soil containing the majority of feeder roots
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5. Cornell Short Course
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6. Soil Infiltration Rates
Soil type Basic infiltration rate (mm/hour)
Sand > ( in./hr.)
sandy loam 20 – ( in./hr.)
Loam 10 – (.4-.8 in/hr.)
clay loam 5 – (.2-.4 in./hr)
Clay 1 – ( in./hr.)
Cornell Short Course
1/20/2009

7. Precipitation Rate How fast the system applies water
Measured in inches per hour (in./hr.)
Varies from station to station
Even varies within a station
Most system’s precipitation rates exceed the infiltration rate
Cornell Short Course
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8. Theoretical Precipitation Rate Formula (Gross Precipitation)
Where:
PRgross = Gross precipitation rate (in./hr.
Q = Flow of station (GPM)
A = Area (sq. feet)
= Constant (Space\Time Continuum)
96.3 x Q A
PRgross =
Cornell Short Course
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9. Infiltration vs. Precipitation
SANDY
LOAMY
CLAY 10 9 8 7 6 5 4 3 2 1
INCHES PER HOUR
10 minutes
20 minutes
Start
Precipitation
Rate
8 minutes
18 minutes
Cornell Short Course
1/20/2009

10. Available Water (AW) Amount of water held in the soil
Measured in inches of water per inch of soil
in./in.
Excess water drains below roots
Storage per inch of soil varies by texture
Cornell Short Course
1/20/2009

11. Permanent Wilting Point
The turf is not dormant, or restin’…
…IT’S DEAD!
It is acceptable to occasionally let the plants in a landscape wilt
This is defined as the Occasional Wilting Point
Extended drought conditions move a plant beyond occasional wilting towards the Permanent Wilting Point
Cornell Short Course
1/20/2009

12. Plant Available Water (PAW)
Amount of water stored in the active root zone
Formula:
PAW = AW x RZ
Where:
AW = Available Water (in. of water/in. of soil)
RZ = Average Depth of Root Zone (inches)
Example:
For loam soil with 7” RZ PAW = 0.17 in./in. x 7 in. = 1.19 in.
Cornell Short Course
1/20/2009

13. Management Allowable Depletion (MAD)
% Of PAW taken out of soil
% Removed; Not % remaining
Varies by soil type and plant species
Determines the amount of drought stress the plant will incur
MAD allows for a safety buffer
Broken mains?
Controller downtime?
Cornell Short Course
1/20/2009

14. Management Allowable Depletion (MAD)
A factor used to adjust the plant water use amount
Based on experiments on turf water use that define the limits of stress that can be applied to turf
Represent a percentage of water that can be subtracted from ET without affecting the health or appearance of the turf
Cornell Short Course
1/20/2009

15. Allowable Depletion (AD)
The amount of water that is used by the plants between irrigation
Formula:
AD = PAW X MAD
Where:
PAW = Plant Available Water
MAD = Management Allowed Depletion
Example:
AD = 1.19 x 0.50 = = 0.60 inches
Cornell Short Course
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16. Example of PAW, MAD,& ET
PAW 1 in.
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17. Effective Rainfall (in.)
Amount Rainfall Stored Rootzone
Fraction Due to Evaporation, Runoff
If Less Than 0.25”, Use 0.00”
Use 2/3’s of Amounts Greater Than 0.25”
Cornell Short Course
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18. Benefits of Scheduling
Water Savings = Money Savings
Healthier Turf
Reduced Chemical Use - Cleaner Environment
Less Strain on Distribution Systems
Cornell Short Course
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19. Base Schedule Based on Average Monthly Conditions
Number of Days to Irrigate
Number of Minutes to Irrigate
Number of Repeat Cycles
Base Schedule Must Be Updated at Least Monthly to Reflect Irrigation Frequency Changes
Cornell Short Course
1/20/2009

20. Microclimate Factor (Kmc)
Shaded part or most of day, courtyard, north building - LOW ( )
No influence from buildings, wind, slope etc. - AVERAGE (1.0)
South face, high wind, slopes, parking lot - HIGH (1.0+)
Cornell Short Course
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21. Key Irrigation Auditor Actions
Identify Equipment Problems
Determine Actual System Performance Based on Uniformity Tests
Adjust Run Times According to Season
Fine Tune Stations to Exposures
Trim Back System to Minimize Water Use
Cornell Short Course
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22. Uniformity POOR UNIFORMITY GOOD UNIFORMITY (NEVER PERFECT) Depth of
Water
(NEVER PERFECT)
GOOD UNIFORMITY
Depth of
Water
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23. Broken Sprinklers
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24. Bad Seals
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25. Improper Pressure
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26. Sunken or Blocked Sprinklers
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27. Existing Schedules
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28. Weeping Valves
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29. Mismatched Sprinklers
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30. Wind Distortion
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31. Misaligned Sprinklers
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32. Cornell Short Course
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33. Check Sprinkler Spacing
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34. Case Study #1
Description: 152 ac. 7 Sites Pre-Audit Water Use = 825,418 ccf (149.6 in.) Post-Audit Water Use = 694,695 ccf (125.9 in.) Water Saved = 130,723 ccf ( 23.7 in.)
Cornell Short Course
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35. Case Study #1 cont.
Value of Water Saved ,723 ccf X $0.46/ccf = $60,132
Cost of Audits ac. X $50/ac. = <$7,600 >
Net Savings
$60, , = $52,532
Cornell Short Course
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36. Methods for Water Conservation
Equipment selection
Proper Scheduling
Sensors
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37. Nozzle Technology
Larger water droplets for consistent performance - even in windy conditions
Effective close-in watering without seed washout
Uniform distribution over the entire radius
Cornell Short Course
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38. Pressure Compensation
Up to 40% water savings
Mid-range Rotors PSI
Athletic/Commercial rotors PSI
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39. Irrigation Central Controls
Act as a throttle for irrigation systems with 2- way communication between PC and system
Weather monitoring for time adjustments
Flow monitoring for for predefined parameters
Cornell Short Course
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40. Irrigation Central Controls
24/7 system monitoring and Feedback
Flow management
Multiple (>500) stations per site
Multiple (>100) simultaneous valves
Multiple sensor inputs
SEEF- Search for and Eliminate Excessive Flows
Map Import
Alarms
Weather stations, ET, Cycle and Soak, Water Window
Cornell Short Course
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41. Soil Moisture Sensors Electromagnetic pulse technology
Digital processing to controller
Measures soil temperature and soil conductivity
Averaging 35% water savings on test sites
Cornell Short Course
1/20/2009