Pajaro Valley Water Management Agency

AG MOBILE LAB PROGRAM

-- IRRIGATION Efficiency EVALUATIONS --

(Attachment B)

Summary

This is one of four Mobile Lab services offered by the PVWMA. An Irrigation System Efficiency Evaluation estimates the water use efficiency and the “distribution uniformity” (DU) of an irrigated block of land. The DU measures how evenly the irrigation system delivers water throughout the field.This service is usually completed at the same time as the pump tests (see “Attachment A”). The test is done according to standard Cal Poly/DWR methodology. Written results are prepared which show the DU. Detailed information on systems pressures, pressure losses, runoff problems, leaks and plugging problems are provided. Recommendations are included for both the current and following irrigation seasons.

What can be expected during the test

  • After the work is authorized by the PVWMA, the consultant works directly with the owner/grower to arrange a date, time and meeting place.
  • The test is run at the same time as a planned, regular irrigation. No special start/stop procedures are needed.
  • The consultant will arrive before the test starts and set up. Catch cans are placed throughout the block to be irrigated, and then are picked-up after the irrigation stops. The test starts with the system off. Measurements are taken before, during and after the irrigation.
  • The test lasts as long as that block’s irrigation is run and is completed by one technician.
  • After the field visit, the written evaluation is prepared, usually within two weeks.
  • A post-evaluation meeting is set up with the consultant, the grower, the irrigators and PVWMA staff to discuss report and related recommendations.

what is needed from the owner/grower:

  • Sign a “cooperators agreement” form
  • Notify the consultant whether translation services will be needed for the field meeting(s).
  • Schedule a day and time for a standard irrigation, and coordinate with the consultant to be on site before the irrigation begins.
  • Meet the consultant on-site before the irrigation begins to show them the system and how that day’s irrigation will be run.
  • Attend a field meeting for about an hour after the evaluation to hear the results. If possible the irrigators should also attend this meeting.
  • Complete a follow-up survey form after the evaluation

other Details

  • Growers are encouraged to schedule an evaluation as early in the season as possible so that adjustments can be made and water savings start as soon as possible.
  • If a Fertilizer Management Evaluation will also be completed, an initial meeting will usually be held with both consultants who will answer questions, learn about the system, and to help choose which block will be tested. The timing of both evaluations should be scheduled to start around the time of planting and first irrigation.

Consultant INFORMATION

Power Hydrodynamics; Power Services, Inc., Modesto, CA (209) 527-2908 or (800) 808-9283