Two decades ago, the water coming out of the Yakima River during irrigation season was so muddy that researchers weren’t sure they could ever clean it up.
Today, the same river in Central Washington is producing water at levels of turbidity that scientists with the Sunnyside Valley Irrigation District previously considered elusive.
The difference? Collecting years of data, improving communication with area landowners and convincing them to buy in.
“We regularly provide data to the landowners, and this helps them comply with state standards for surface water,” said Elaine Brouillard, the water quality supervisor for SVID. “We’re one of the first labs in the nation that has done this level of testing, and the program has proven to be extremely effective.”
For example, the turbidity in the Granger Drain — one of four areas managed jointly by the SVID and Roza Irrigation District — has dropped from more than 220 NTUs (Nephelometric Turbidity Units) in 1997 to fewer than 20 NTUs during the 2018 irrigation season.
The other three drain areas managed by SVID and Roza have been at or below the state standard of 25 NTUs for more than five years, Brouillard said.
“Back when this research started, we weren’t even close,” she said. “But over time, and through best management practices, we’ve seen the situation completely turn around. Our districts are now in the 90th percentile for water quality standards, but there was a time when that seemed hard to attain.”
In addition to monitoring turbidity of water in the district, the SVID also tests for fecal coliform bacteria and E. coli bacteria.
The Roza-Sunnyside Board of Joint Control built a state-of-the-art lab in Sunnyside in 2015, which has improved efficiency and given researchers more room to complete their work.
The lab works closely with state and federal agencies, including the Washington State Department of Ecology, and the U.S. Geological Survey and Bureau of Reclamation.
“We have cooperative arrangements with all of the regulators, and all of the testing is based on standard methods,” Brouillard said. “We only do sampling at safe points of compliance, and only certain people are allowed to do it. The lab’s goal is to remain completely neutral.”
Cooperation from the lower Yakima Valley farmers has been equally critical to the turnaround in the region’s water quality over the past 22 years.
Brouillard said, at first, some landowners were skeptical about the water quality testing program. But once they started taking steps to improve the overall water quality in the area, they began to see the benefits.
By structuring the program as a partnership — as opposed to an enforcement mechanism — SVID found that more farmers were willing to go along with the plan.
“Our job is to make sure all surface water returns in the district are up to state standards, but our main function is to help people be in compliance,” Brouillard said. “We don’t cherry pick data or push any kind of agenda. Our decisions are based solely on the data we collect.”
The Water Quality Laboratory has been logging water quality data from the Yakima River since 1996, giving the two irrigation districts a perspective that few others have.
Brouillard pointed to similar research being conducted at Washington State University and at the University of California-Davis, but as far as she is aware, SVID’s efforts stand alone.
“The robust database we’ve collected is unequaled, and that is what has allowed us to make such major strides over the years,” Brouillard said. “We are setting goals and achieving them in a scientific, neutral way. It’s been a slow process, but it has been very effective.”