Irrigation System Performance

Transcription

1 Irrigation System Performance Observations from the MIL & the importance of DU Kevin Greer RCD of Tehama County

2 My Background Managed the MIL program since 2009 ITRC auditor training Cal Poly SLO 642 system audits: 10 counties, 23,600 acres Certified CLIA from IA 8 years of landscape irrigation installation Moved 1,000s of sprinkler pipes!

3 MIL Statistics

4 Key Ingredients of Efficient Irrigation Soil characteristics Weather and crop water use System application rate Scheduling Distribution Uniformity (DU)

5

6 Distribution Uniformity - DU A measure of how even an irrigation system applies water to an area. Getting the system close to 100% is the goal. Lower DUs = increased irrigation water. The lower the DU, the less efficient the distribution, and thus the more water that must be applied to meet the minimum requirement.

7 Similar to Irrigating Your Lawn What is the most common way to resolve this issue? Perform audit Check pressure Adjust sprinklers Run system longer!!! In ag irrigation these differences can not be seen! How can you tell this is overwatered?

8 Why is DU Important?

9 Poor DU s = Over & Under Irrigation

10 psi System details Netafim Supernet Jr. Micros with blue nozzles and 25 psi regulators

11 Pressure changes flow rates!

12 Compare Field Data to Sprinkler Specs PSI Flow, High Flow, Low Average Location Location Location Difference between high and low = 3.8 gph 3.8 x 36 hr run time = 137 gal x 20 cycles = 2736 gal

13 So What Are the Issues With This System? Unbalanced & low pressures Design? System not running up to original specs Possible changes in the pump Hardware specs not met Pump 24psi, Regulators 25psi Incoming pressure must be higher

14 GPH GPH Range on Micro Sprinklers 60 Sprinklers Tested, DU=75% gph.73 gpm gph.81 gpm gph.38 gpm gph.49 gpm gph.54 gpm gph.59 gpm gph.65 gpm

15 GPH Range on Micro Sprinklers 60 Sprinklers Tested, DU 87% gph.47 gpm gph.50 gpm gph.53 gpm gph.56 gpm gph.60 gpm gph.63 gpm gph.41 gpm

16 50.00 GPH Range on Micro Sprinklers 60 Sprinklers Tested, DU 96% gph.63 gpm gph.67 gpm gph.69 gpm gph.70 gpm gph.73 gpm

17 The Importance of High DUs? DU Low High Difference 24 hour Total 15 Cycles Gallons Gallons Gallons

18

19 What Does it Take to Maintain High DUs? System inspections Similar to checking oil in car or truck Check well and pump Water levels fluctuate Bowls wear Follow manufacturer specs Install flow meters Instant system feedback Consult design plans & check psi Design needs to be engineered! Good filtration Install gauges before & after filter Maintenance!

20 Flow Meter Use in NSV

21 How to check pressures and flows

22 Checking Pressure 3 tools Available at most irrigation suppliers

23 Where to Check? The key is knowing the design layout Inlets Closest/furthest hydrologically to the pump Ends of lines

24 Now Check the Flow Check in high and low pressure areas

25 Treat your irrigation system like a tractor! With maintenance it will last longer and perform better

26 Maintenance Tips, System Flushing SS, flush lines on a regular basis Use flush outs! Micros, flush lines at least twice per season Check most distance lines more frequently Be sure to open lines long enough (30-60 seconds)

27 Inlet screens Check regularly Maintenance Tips Most distant lines accumulate most frequently Install pressure gauges Possibly remove

28 Know Manufacturers specs Check, clean and flush regularly Dynamics of well can change Use pressure gauges! Maintenance Tips 2 way assembly recommended

29 Maintenance Tips Biological contaminants Can have dramatic effect on micro systems Good filtration can help May need chemical injection Check lines frequently

30 Sprinkler & Nozzle Tips Use one type of sprinkler! Use one size of nozzle! Small changes in sprinkler nozzles = large differences in flows Follow manufacturer's specs Replace nozzles on regular schedule Perform flow test Every 5-10 years Dependent on wear & tear

31 Maintenance Tips The Challenge of Leaking Leaks are sources of wasted water Common causes Old worn parts Poor repair practices Animals

32 Maintenance Tips Minimizing leaks Repair leaks promptly and properly Splice in new line if needed Replace deteriorating equipment At first signs Animals Strategies depend on severity of problem

33 More challenges More maintenance Frequent system checks are encouraged Parts break or malfunction on a regular basis!

34 So the DU Take home is. Any combination of Variations in pressure Lack of maintenance Mixing nozzles and sprinklers Changes in pump dynamics = Decrease in DU Poor DU = Variations in sprinkler flow rates = Lack of uniform water application = Crop health & yields are jeopardized!

35 Reach Me At Kevin Greer This presentation is available at: tehamacountyrcd.org