End of the 2023 irrigation season

Roza Water Users:

  • USBR issued a new water forecast of 73% in September, which is an increase of 1%.
  • Roza will stop diversions for the season on Wednesday October 18th .
  • A limited amount of Tier II water is now available. This is possible because of a combination of the increased water supply forecast, reduced demand due to cooler than average weather, some growers not taking all the water that they order, and the restrictions implemented earlier in the season.
  • The Roza system was run the tightest it has ever been run this season, due in part to the availability of the Wasteway 5 re-regulation reservoir north of Sunnyside. Our Watermasters work very diligently to not have operational spills cause water going into the wasteways during drought years. When water is ordered but not taken operational spills can occur.
  • There have been 7,000 acres of conversions to drip irrigation since the 2015 drought.
  • With the shift into an El Nino weather pattern the long range forecast is for generally drier and warmer conditions in the northwest for 2024. Each El Nino is different and not all El Nino cycles are bad, but they certainly can create poor conditions for water supplies. Recent research shows that El Nino cycles typically reduce precipitation by 10% to 20% and La Nina cycles typically add 10% to 20% from the base weather pattern.