An unseasonably dry March and lack of sufficient water supplies have foiled a proposed water release by the Oakdale and South San Joaquin Irrigation Districts that would have boosted Stanislaus River flows beginning this past week for the benefit of out-migrating salmon, and also supplied water to farms and communities in the San Joaquin Valley most vulnerable to extreme drought conditions.
The plan would have sent up to 100,000 acre-feet of water down the river between April 15 and May 15 in what are known as “pulse flows” to help young salmon navigate their way toward the Delta and, eventually, out to sea. The extra water, once it reached the Delta, would have been available for export to south-of-Delta farms and communities in dire need of supplies this year.
A lack of snow and rain in the winter and a less than desirable showing in March and April played a major part in scuttling the pulse flow. State water supply projections by the California Department of Water Resources published earlier this month – which includes the Stanislaus River basin – were revised downward from previous estimates.
“That change was significant and took away any options to provide water for a pulse flow,” said OID General Manager Steve Knell.
The lack of water supply is forcing both Districts to look at possibly implementing operational changes this year to meet their own customers’ water needs.
“It’s going to be a challenging irrigation season,” Knell added. “I’m confident our crews are up to the challenge of meeting customer needs even with supplies being tight.”
A smaller pulse flow will still occur, albeit at a lesser rate without the Districts’ water added and far less than pulse flows that the Districts historically provided and made available based on their own investments in conservation and efficient water delivery practices.
“The current pulse flow is far smaller than what we were proposing,” explained SSJID General Manager Peter Rietkerk. “The fish really could have benefitted from the additional shot. I’m also concerned for the communities in the San Joaquin Valley who have endured more than a year of COVID-19 and now are heading into the irrigation season with little or no water supplies.”
Another factor in torpedoing the proposed pulse flow was the unwillingness of the U.S. Bureau of Reclamation to participate. The irrigation districts sought concurrence in early March from the Bureau to release surplus water stored at New Melones Reservoir that OID and SSJID have historic rights to.
The Bureau of Reclamation – which controls releases at the reservoir – refused to participate, despite weeks of negotiations and the pleading of their own Central Valley Project customers.
The South San Joaquin Irrigation District was established in 1909 and is located in Manteca. It provides agricultural irrigation water to about 55,000 acres in Escalon, Ripon and Manteca. In 2005, SSJID expanded into providing domestic water service to selected cities in southern San Joaquin County.
The Oakdale Irrigation District was created in 1909 and provides agricultural water to about 62,000 acres in northeastern Stanislaus County and southeastern San Joaquin County. OID and SSJID hold senior water rights on the Stanislaus River. For more than 100 years, the Districts have responsibly delivered surface water to farms in San Joaquin and Stanislaus counties, and for SSJID, thousands of homes in San Joaquin County.
The Districts are committed to sensible water policies, innovative irrigation techniques, prudent conservation practices, and important investments in biological studies of the river and fish habitat.