What's at stake:
A billion dollars has been pledged to restore the San Joaquin River.
Just north of Fresno, a multi-national company wants to build a gravel mine on a riverbank that holds many ambitions.
CEMEX, the $15 billion mining behemoth headquartered in Mexico, is asking the Fresno County Board of Supervisors on Thursday for permission to blast the riverine area into a 300-ft-deep pit whose girth would almost span the Golden Gate Bridge.
State and federal agencies have a more bucolic vision in mind. The State of California wants to turn the neighboring area into the biggest park system in Fresno. And the Bureau of Reclamation plans on restoring the river right next to the mine so that salmon can spawn there again. All told, about $1 billion in taxpayer funds have been pledged to achieve the park-and-salmon idea.
This vision for the San Joaquin River corridor is under existential threat by the CEMEX proposal, according to UC Berkeley professor and fluvial geomorphologist Mathias Kondolf.
It’s practically guaranteed that a flood will cause the gravel mine to spill into the river, said Kondolf, an expert in managing flood-prone lands, harming the salmon run and potentially altering the course of the river that downstream farmers and the parkway rely on.
“It’s not a matter of if, but when those levies separating this massive pit from the river are breached,” he said. “There will be all kinds of chemicals that wind up in the water.”
“This eventuality is threatening the viability of the huge restoration project which is of national importance. This national investment is now being threatened,” he added.
The Bureau of Reclamation and the State Department of Fish and Wildlife have written letters to Fresno County speaking to this exact risk. However, the county dismissed their concerns, according to the county’s environmental analysis documents for the project.
County planners responded to the letters calling the scenario unlikely and said only that CEMEX would cooperate with regulators.
“In the unlikely and unforeseeable event that the Quarry Site is ‘captured’ by the SJR… the operator would work with several local, state and potentially federal agencies for any necessary remediation activities.”
CEMEX’s lawyer, Patrick Mitchell, did not respond to multiple requests for comment.
The impacts of a river breach on the mine could be so significant, its harm to the river so irreparable, Kondolf said he didn’t know whether the river could even be brought back to its current state.
“Can you restore?” he wondered.
Fresnoland asked Fresno County to clarify what damages, if any, CEMEX would be responsible to pay for if the spill were to happen.
The county declined to answer.
“Our Public Works team is receiving many public comments and questions daily and don’t have enough time to respond to them,” wrote County communications director Sonja Dosti in an email on Tuesday.
‘A real red flag’ that was ignored
The outer edge of CEMEX’s mine is in the federally designated floodplain for the San Joaquin River.
But the company wrote their own flood map which claims their mining site is not in the floodplain.
In the case of a big, serious flood, the river’s water line will come within inches of breaching the top of the pit’s protection berms, CEMEX’s analysis from this year shows.
The river’s water could be moving so fast that, according to the Bureau of Reclamation, the berm’s wall risks collapse from erosion. In such a case, water deliveries to farmers in the area would be thrown into doubt, too.
“Breaching of the proposed project sites by high flows,” the Bureau of Reclamation wrote, “could cause long-term impact to fisheries, the ability for Reclamation to provide water to Holding Contracts below the proposed project site… and potentially the ability of Reclamation to deliver water to Mendota Pool for the Exchange Contract.”
The planning team for Fresno County has said they did not consider putting the mine in a different location, claiming it wasn’t their responsibility to search for one.
Ultimately, for the only location that the county has reviewed for the mining proposal, there simply aren’t enough safeguards in place to guard against these far-reaching impacts to the region, Kondolf said.
“It seems like a real red flag to me. It should have been a disqualifying approach,” said Kondolf about the decision to rewrite the flood maps.
“If you’re talking only 7 inches of freeboard, that’s not much. It’s as good as over top,” he added.
It is unclear why CEMEX would go forward with such risks to their mine. Again, Mitchell, CEMEX’s did not respond to multiple requests for comment.
There have been two major gravel mining breaches on the San Joaquin River near Fresno. One of the biggest is the big lake on Milburn Avenue, on the river bluffs. The “lake” was actually an old gravel pit that got breached in the 1990s. The state and federal government have spent millions trying just to seal off the old mine from the river system.
A second breach in 2005 was covered by taxpayers, too.
“Sycamore Island was $4.5 million,” said Kari Daniska, the chief executive officer of the San Joaquin River Conservancy. “It was the Conservancy (which is funded by taxpayers) – we footed the entirety of the bill.”
Such a breach of CEMEX’s berms has happened before in California. For example, one Bay Area site was breached in 2023, during one of the wettest years in California history.
Kondolf cautioned that these mines are surface mines — not very intensive. A blast mine like CEMEX is proposing “is a whole different animal,” he said.
When gravel pits get very deep, they can have very large consequences if breached in a flood. For example, in 2021, when floods hit Germany, a raging river overwhelmed a 200-foot-deep gravel mine operated by German mining company RBS. The massive pit eventually cut a canyon hundreds of meters long and swallowed up homes.
“Already the lower San Joaquin is impacted by aggregate mining. This takes it to another level,” he said.
“It seems like a pretty absurd proposal to me.”
Fresno County Supervisors will be taking a final vote on the CEMEX proposal on Thursday at 9:30 AM, at the Hall of Records in downtown Fresno.
