Starting today, no more surface water may be used for irrigation in the Yakima Basin through the remainder of October. 

While the primary irrigating season is nearly over, the state Department of Ecology said the “unprecedented halt to surface water use” is necessary after three consecutive years of drought and historically low streamflows and stored water in reservoirs, which are expected to run out after Oct. 6. 

Ecology anticipates the cutoff may affect as many as 1,500 water right holders and that local communities may need to restrict residential watering. 

“We have not experienced a drought like this in over 30 years, and it’s forcing us to take actions we’ve never done before,” said Ria Berns, Ecology’s Water Resources program manager, in a statement. “We know that restricting water diversions will impact communities across the Yakima Basin, but this is a necessary step to protect water for fish and senior water rights in the face of continued drought conditions.” 

When water supplies are running low, Washington water law requires the most senior water right holders to receive their full amount before junior water right holders can access the remaining water. In the current situation, water supplies are so low that only the most senior water right holders in the basin can access what remains. 

Ecology will notify water right holders of the restrictions by mail this week. Water users in the Yakima Basin should be aware that Ecology staff will be checking to ensure diversions are off. 

In the Tri-Cities, Kennewick Irrigation District is scheduled to stop water delivery on Oct. 12. The city of West Richland has announced it would cease irrigation deliveries on Oct. 14. 

Columbia Irrigation District, which serves customers stretching from the Wanawish Dam on the Yakima River to where it enters the Columbia River and then areas east and south of Kennewick, said via its website it would provide irrigation water through Oct. 15. It also posted a notice that “due to unforeseen circumstances, Columbia Irrigation District will no longer be entering into an agreement with Ecology.”