1. Irrigation Evaluation
Dotty Woodson
Extension Program Specialist
Water Resources
Texas A&M AgriLife Extension
Dallas Research and Extension Center

2. Water Issue – Is there Enough?
Population and development will double by 2060
New water resources will cost billions of dollars
Conservation is the easiest and least expensive way to make our water resources sustainable

3. Efficient Irrigation
Future sustainable landscapes must use water as efficiently as possible

4. Current Situation
Water usage increases 35 to 70% during the summer

5. How Many Gallons One acre = 43,560 square feet
▪ One-acre feet of water = 26,136 gallons
▪ Every time you apply one inch of water to your landscape, you apply gallons of water per square foot
1/5 acre = 8,712 square feet
8,712 x 0.6 = 5,227 gallons
5,227 x 16 irrigations = 83,632 gallons
This calculation show water used in 3 months watering once a week.
The point to make is not all parts of the landscape require 1 inch of water a week.
Plant water requirement is the main factor to reduce landscape water use. There are plants once established require very little supplemental water except in July and August

6. Efficient Irrigation How Often How Long When Seasonally
How often – every 5 to 7 days during summer; 7 to 10 days spring and fall; 10 to 20 days during winter
How long can only be determined by precipitation rate/catch can test because each system and soil is different.
When: after 6:00 pm and before 10:00 am

7. Efficient Irrigation

8. Even Distribution of Water
Even distribution is necessary for good growth

10. Irrigation System Evaluation vs Irrigation System Audits There is a difference
Even distribution is necessary for good growth specially on the lawn

11. Irrigation Evaluation
Most irrigation systems are not efficient
60% or less
Poorly maintained
Leaks, Misaligned heads, etc
Rain and Freeze senor
Adjust controller each season
Conserve water
Save money

12. Irrigation Evaluation
Purpose:
Check Irrigation Efficiency
Create an Efficient Irrigation Schedule
Identify Problems with Irrigation System
Potential Water Savings
Potential Dollar Savings
Improved Water Distribution
Increased Quality of Landscape
Excellent Neighbor Relations
Most Accurate Method to Determine Run Times

13. Irrigation Evaluation
▪ Site Inspection with Home or Business Owner/Representative
Run each Zone/Station
Identify Problems
▪ Irrigation Scheduling
• Irrigation frequency
• Run times per zone

14. Most Common Problems Clogged nozzle Misaligned heads Misdirected heads
Mismatched heads
Leaking or Broken pipes/heads/valves
Too high or too low water pressure
Irrigation head too low
Grass too high
Tree, shrubs, groundcover grown to block irrigation
Poor Design
Dry landscape areas or poor coverage
Water bubbling, dripping or gushing all the time
Runoff occurs before adequate water applied
Area along road, driveway or sidewalk stays too dry
A leaking pipe may not be obvious but will effect performance by lower the pressure that makes the system work well whereas a broken pipe or head is obvious.
Too high pressure causes overspray which create a huge loss due to evaporation and does not distribute the irrigation water properly.
Low presure does not allow the system to work properly. Create poor coverage.
Irrigation head too high will get run over by mower. Best to irrigate after mowing. Keep grass mowed or raise head.
Grass too high will out allow poor distribution. Lower head.
If tree or shrubs have grown in the way, adjust heads by rising or lowing.
Usually because landscape has changed since original design. In some cases sprinkler systems can be reworked for new designs, in other cases a new system using the old main lines or new main lines may have to be designed.

15. Same irrigation as in previous picture only on a rainy day
Same irrigation as in previous picture only on a rainy day. Spray irrigation is most inefficient because of water lost to evaporation and displacement. Replace heads with nozzles that put water out in haevt droplets like Hunter PM rotators or Toro Precision nozzles. It is a easy change such as just remove old nozzle and replace with new.

16. Irrigation water displaced by wind

17. Over watering causes erosion and loss of good turf

18. Grass too tall or sprinkler too low. Irrigate after mowing
Grass too tall or sprinkler too low. Irrigate after mowing. If sprinkler still to low, raise sprinkler head.

19. Tree blocking good coverage. Move sprinkler if need the coverage
Tree blocking good coverage. Move sprinkler if need the coverage. Under shrubs, either raise or lower sprinkler or better convert to drip irrigation.

20. Catch Can Test
Place 5 to 9 catch cans (tuna or cat food cans work great) in each irrigation zone or station.
Run each zone for 3 minutes To determine run time (time each station should run)
Some irrigation systems apply water faster than the ground will absorb 1 inch of the water so water run off. To this, you may need to run these stations several short times instead of one long time.
If the water level in each catch can varies greatly, go through the Irrigation Check to help identify problems
Test each zone. Water application and distribution can vary by zone.
Place 5 to 9 catch cans (tuna or cat food cans work great) in each irrigation zone or station.
Run each zone for 3 minutes to determine how much water is applied in each zone by measuring the amount of water in each catch can.
To determine run time (time each station should run) use this example: if there is ¼ inch of water in each catch cans after running for 3 minutes, to apply 1 inch of water set the run time for 12 minutes (This is just an example, your measurements could vary greatly). Some irrigation systems apply water faster than the ground will absorb 1 inch of the water. To avoid water running off the landscape into the street, you may need to run these stations several short times instead of one long time. With this example, set the controller to run 6 minutes 2 times. See ‘Soak and Cycle’ and ‘Aerate Lawn Area’ for more ideas.
If the water levels in the catch cans are equal or near equal, your irrigation system is working efficiently (distributing water evenly). If the water level in each catch can varies greatly, go through the ‘Irrigation Checkup’ below to improve distribution of water in that zone.
Test each zone. Water application and distribution can vary by zone.

21. New Irrigation Technology Saves Water
Replace wasteful spray nozzles with water saving multi-stream nozzles
Hunter Industries
MP Rotator
Toro
Precision
Rain Bird
Rotary Nozzle
New water efficient nozzles put water out in heavier droplets so not so much water is lost by evaporation and displacement.

22. Soak and Cycle
Determine how long to run each zone (see ‘Catch Can Test’)
Water these areas in 2 or 3 short cycles or 4 cycles if on a slope instead of 1 long cycle.
Wait 20 to 30 minutes between cycles.
Most irrigation controllers have a way to set different start times. If you have trouble programing your controller, visit the irrigation controller company’s web site or contact their customer service for instructions.
Some newer controllers have a soak and cycle settings, so this may be a good time to upgrade your irrigation controller.
Some irrigation systems apply water faster than the ground will absorb 1 inch of the water. This is especially true in lawn areas. Mulched areas absorb water more efficiently. To avoid water running off the landscape into the street, you may need to run these stations several short times instead of one long time. Use soak and cycle method by:
Determine how long to run each zone (see ‘Catch Can Test’)
Water these areas in 2 or 3 short cycles or 4 cycles if on a slope instead of 1 long cycle.
Wait 20 to 30 minutes between cycles.
Most irrigation controllers have a way to set different start times. If you have trouble programing your controller, visit the irrigation controller company’s web site or contact their customer service for instructions for soak and cycle. Some newer controllers have a soak and cycle setting, so this may be a good time to upgrade your irrigation controller.

23. Rain and freeze sensor. By state irrigation rules, a rain sensor is now required on all irrigation systems. By city irrigation rules a rain and freeze sensor is recommended in location where freezing weather occurs.

24. Resources http://irrigation.tamu.edu/

25. For More Information
Dotty Woodson
Extension Program Specialist- Water Resources
Biological and Agricultural Engineering Department
Texas A&M AgriLife Extension
17360 Coit Road
Dallas, Texas 75252