Understanding Aquatic Treatments

  • Roza treats water in the canals to control algae and aquatic weeds under a permit issued by the Department of Ecology. Without these treatments water cannot be delivered efficiently.
  • Red dye is used at the beginning of a treatment to track travel of the chemicals in the water. Blue dye is used to mark the end of the treatment. The speed and travel time vary depending on the flow in the canal.
  • 11.0 mile on the Main Canal is 11 miles downstream of Roza dam. The mile markers get larger the farther they are down stream from Roza dam. If your delivery is at 49.7 mile you are only affected by treatments made upstream.
  • Treatment sites with a P indicates a pump lateral canal. Treatments on pump lateral canals affect only the lateral being treated and not the main canal.
  • When delivery point is listed as a treatment location, the treatment occurs immediately down stream and does not affect the listed delivery point.
  • If you need confirmation that your delivery point was ordered off during a treatment, talk to your ditchrider. Deliveries will not be closed unless ordered off.
  • Notices of treatments are posted on the Roza website a minimum of 24 hours prior to the beginning of treatment.
  • Check the Roza website frequently for updates.
  • If you have any questions or would like to discuss you particular situation do not hesitate to contact Elaine Brouillard, Water Quality Specialist at 509-837-6980.

"Working together proactively to preserve, protect and enhance our water and land resources."