Category Archives: Activities & Projects



West Extension Irrigation District will be applying the aquatic herbicide “Argos” (chelated copper) in its main canal in 3 treatments:

  1. Upper Canal (Phase 1 Inlet to Division) – Wednesday July 17
  2. Middle Canal (Division to I-84) – FRIDAY JULY 19
  3. Boardman Canal (Siphon to end) – THURSDAY JULY 18

Treatments will start at approximately 7 am and last for 6 hours.

Argos targets algae and is applied at the rate of 1 ppm for a 6 hour set.  This low rate of application means there are no holding restrictions on the water.  This compares to the Copper Sulfate Crystals which are applied at a 5-6 ppm rate and have lengthy holding time.

Please call the office if you have any questions at 541-922-3814.

Canal Treatment Scheduled

West Extension Irrigation District will be applying the aquatic herbicide Cascade with active ingredient Dipotassium salt of Endothall  to its Main Canal on Tuesday, June 19, 2019.  The canal will be presumed to have treated water for 24 hours.

It is labeled safe for all uses EXCEPT:  NEWLY PLANTED ANNUALS, ORNAMENTALS, GRASS, and SOD.  It is also likely to be harmful to fish in ponds (contained areas).

If you require further information, please contact the district office at 541-922-3814.   

Tentative Canal Treatment dates

West Extension Irrigation District has tentatively scheduled the following canal treatments. Regular notifications will go out for each treatment as date is confirmed.

June 19 – Cascade (Endothall)

June 26 – Copper Sulfate

July 10 – Magnacide H (Acrolein)

July 17 – Argos (Chelated Copper)

If you wish to be placed on the notification list, email with your request. You will be placed on the list until you notify the office in writing that you no longer wish to be notified, or until you sell your property.

If you have any questions, call the office at 541-922-3814.