Lawn and Garden

Overwintering Your Irrigation System

Ted W. Tyson, Extension Agricultural Engineer

Larry M. Curtis, Extension Agricultural Engineer

Irrigation system maintenance is always important, but especially so at season end. Following is an end-of-season checklist of procedures to protect the system and ensure that it will be ready for next season:

1. ENTIRE SYSTEM

    Super-chlorinate to clean out entire system. Backflush sand filters; then inject liquid bleach (5.25% chlorine) at a concentration of 500 parts per million (see ANR-651, Chlorination to Prevent Clogging) . Allow for a minimum of 30 minutes contact time at the farthest emitter. Shut the irrigation system down for 24 hours and then flush the system in the following order:
      • filters
      • mainline and submain
      • lateral lines

2. FILTRATION EQUIPMENT

      • Flush and drain filters
      • Inspect interior components of media filters, centrifugal separators, and screen filters for wear, damage, corrosion and other signs of deterioration
      • Check condition of seals, gaskets, and valve seats.

3. VALVES

      • Completely drain all valves
      • Clean corrosion, dirt and other foreign matter from valves
      • Lubricate valves
      • Make sure all valves are open

4. CONTROLLERS AND SENSORS

      • Clean controllers and sensors
      • Check condition of controller panel seals
      • Remove and store batteries
      • Flush and drain hydraulic control conduits
      • Disconnect field wires
      • Check for frayed, worn or broken electrical conductors

5. CHEMICAL INJECTION EQUIPMENT

      • Thoroughly flush and drain injection equipment
      • Clean interior and exterior equipment surfaces
      • Lubricate pumps, motors and gear reducers
      • Examine condition of check valves and backflow prevention equipment
      • Cover shaft and other exposed metal with protective lubricant to prevent corrosion
      • Check condition of gaskets and seals

6. ELECTRIC MOTORS

      • Clean dust, debris, and caked-on dirt and oil from motor
      • Visually check motor windings insulation
      • Lubricate all bearings
      • Cover motor to protect against rodents, insects and dust being sure to provide ventilation to prevent condensation

7. CENTRIFUGAL PUMPS

      • Drain all water from pump and piping.
      • If possible, remove suction lines from water source and store.
      • Make sure all oil- or grease-lubricated bearings are well covered with lubricant.
      • Cover shaft and other exposed metal with protective lubricant to prevent corrosion.
      • Remove suction cover or volute of horizontal centrifugal pumps to check wear ring and impeller wear, and to clean debris from impeller and volute.
      • Remove packing gland and packing to check wear on shaft sleeve.
      • Repack pump (do not tighten).
      • Make sure all passages for liquid are not obstructed.
Publications included in the Alabama Micro-irrigation Handbook present up-to-date information on practical irrigation methods that save energy and water while protecting water quality. For more information, see your county Extension agent.

Publication No.

Micro-Irrigation Handbook ANR-655
Jan. 1999

Larry M. Curtis, Extension Agricultural Engineer, Professor, Biosystems and Agriculture Engineering, and

Ted W. Tyson, Extension Agricultural Engineer, Biosystems and Agriculture Enginneering.

Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability.

This document is author-produced (unedited).