The Merced River Ran Dry… And Nobody Knew About It
A dry Merced River bed, where it would have flowed under Hatfield Bridge, September 14, 2022. Credit: CA Dept. of Fish and Wildlife (CDFW).
It’s difficult to believe that it really happened, but during the summer of 2022, the Merced River, the 14th largest river in California, ran completely dry for four months near its confluence point with the San Joaquin River. The river, which serves as essential habitat for listed species including spring-run Chinook salmon and steelhead, originates in Yosemite National Park, flows out of the Sierra Nevada Mountains, through the Central Valley, and then into the San-Francisco Bay Delta. The river was completely dry and impassable for four miles.
The Merced River at Hatfield Bridge, May 9, 2022. Credit: CDFW.
This issue ended up buried in bureaucratic correspondence, so this story of a major California river running dry was unknown to the general public—until I got a tip about the issue in December 2023. I knew that this was news of national significance, so I pitched the story to the New York Times, which ultimately dropped a bombshell article about the dry river in January 2024 (1). In response to the New York Times investigation, the California State Water Resources Control Board (Water Board) issued its first public statement since the river ran dry in 2022, claiming that water users drained the river legally.
“A dry river is a catastrophe, the water board should anticipate, manage and prevent this from happening.” – Keiko Mertz, Policy Director, in the NYT article
2022 wasn’t the first year of severely dry conditions on the lower Merced River. A cursory analysis I performed found that the river ran dry in August of four out of ten years (2014, 2016, 2021, and 2022). I looked only at flows during August of each year to generally represent mid-summer flows on the lower Merced. Additional analyses could reveal more dry periods. I think they would.
In June of 2016, the final year of a severe drought, a small water district on the lower Merced asked the Water Board to investigate water theft. In the letter, the author stated, “I do not want to become a very unpopular whistle blower with my neighbors, many of whom are in my church every Sunday, [but] something must be done.” The letter then provided parcel maps that highlighted non-riparian parcels (not located along the river), and their corresponding riparian diversions. State data shows the river ran dry as early as May of that year(2).
Graph of streamflow on the lower Merced River showing flows at 0 for nearly 4 months straight. Credit: CDEC.
What happened when the state found out?
The Water Board didn’t respond until July 2021, when it sent a response letter stating that its resources were overwhelmed during the drought and that “It is impractical for staff now to investigate alleged violations from the previous drought.”
In January 2024, Friends of the River sent a letter to the Water Board(3) urging it to prevent the Merced River from running dry again by adopting minimum flow regulations. We have not received a formal response. In the interim, the Water Board created a web page dedicated to the 2022 Merced River dry conditions(4), noting that staff is working to better understand the cause, and will update the web page when that information is ready.
Further reporting by the San Francisco Chronicle(5) revealed the myriad obstacles to guaranteed instream flows, including poor reporting, lack of timely data, lack of clear information, and importantly, limitations on the Water Board’s authority—both legally and politically. Some of the water users on the Merced River have “pre-1914” water rights, which have priority over almost any other type of water user, and are extremely slippery to regulate. But, hey, they stole that water fair and square.
Is anybody paying attention to the Merced River?
The mighty Merced River originates in the high country of Yosemite National Park, flowing down through the valley beneath towering, snow-draped granite walls, and ultimately joins the San Joaquin River in the Central Valley… most of the time. 1969. Credit: CA Dept. of Water Resources (DWR).
Friends of the River has no plans to back down from our work to protect and enhance the Merced River, in collaboration with local Merced River activists.
Last year, we signed a Memorandum of Understanding alongside Merced River Tribes, government agencies, and other environmental organizations to work on reintroducing salmon and steelhead into the upper Merced River, above the major dams—with the ultimate goal of salmonids one day swimming into Yosemite Valley again.
Last month, FOR and other environmental organizations filed comments on the Water Board’s draft water quality certification for the Merced River hydropower projects. The water quality certification is a permit that places conditions on hydropower projects that ensure they do not negatively impact the water quality of the State. In our comments, we advocated for:
Minimum flows that protect fish and wildlife, the ecosystems on which they rely,
Salmon reproductive habitat enhancement (addition and maintenance of spawning gravels),
Responsible reservoir management, which ensures resources for future times of need,
Inclusion of Merced River Tribes in local river and watershed management forums, and
Supported riparian and floodplain habitat improvements, among many other things.
Because the risk of drying up the lower Merced River persists, we will be monitoring the State’s flow gauges during summer to look for red flags and abnormalities. We intend for there to be no more long delays between flow hitting zero, and public awareness.
Friends of the River has a long history of defending the Merced River. Our portfolio of work on the Merced includes, alongside the Merced Canyon Committee, leading a successful campaign to designate a stretch of the Merced River as a federal Wild and Scenic River, participating in hydropower relicensings through the Federal Energy Regulatory Commission, and successfully litigating Merced Irrigation District’s attempt to weaken the power of the federal Clean Water Act (for water wonks – the litigation was to prevent waiver of the State’s authority to issue a water quality certification pursuant to § 401). We work in coalition with many passionate organizations. We’re not going away – and we’re continuing to explore ways to prevent the river from disappearing again in future summers.
How do YOU feel about the Merced River? Drop a comment below.
McClure Reservoir on the Merced River at extremely low levels during drought conditions in 2015. The reservoir is used as storage for hydropower operations and irrigation. Credit: CA DWR.
Resources
(1) New York Times: They Abducted a River in California. And Nobody Stopped Them
(2) See California Data Exchange Center, Station ID=”MST”, timeframe: May 1, 2016 through May 30, 2016
(3) FOR, CSPA letter to the State Water Board urging instream flow protections
(4) Water Board “Merced River Conditions in 2022” web page
(5) San Francisco Chronicle: A major California river dried up below Yosemite. The reason was a mystery — until now
