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Tijuana River Estuary Endures In Face Of Many Ecological Challenges

Birds gather to feed in the Tijuana River Estuary on Sept. 5, 2017.

Photo by Erik Anderson

Above: Birds gather to feed in the Tijuana River Estuary on Sept. 5, 2017.

Brian Collins stands on a sandy beach near the mouth of the Tijuana River.

"This is the Pacific Ocean," he said as he spread his arms toward the open water.

The U.S. Fish and Wildlife Service biologist turns and focuses on a narrow channel that connects the ocean to the sprawling Tijuana River Estuary. Collins watched the salty ocean water flow inland. Two white birds are perched on the sand, staring intently at the moving water.

"Yeah," Collins said, "we have a couple of snowy egrets waiting for fish to come and go."

This is where San Diego's infamous raw sewage flows find the ocean. This past winter, hundreds of millions of gallons of sewage spilled through the Tijuana River Valley and out to sea. The brown water was so smelly at times that Imperial Beach residents felt like they could not leave their homes.

But while sewage flowed freely out of this river mouth, it is also a key part of the complex system that supports life in the estuary.

RELATED: Federal Officials Discuss Cross-Border Sewage Spills At Public Hearing

"This little river mouth feeds this entire wetland and this is the largest estuarine wetland left in Southern California," Collins said.

Water was flowing into the estuary through the narrow opening in the beach. The tidal-driven flow brings salt water to the marsh and mudflats that cover the valley floor.

"So this is a pinch point," Collins said. "It's kind of like your aorta. You know, you need that to stay open to stay alive. This estuary needs this river mouth to stay open."

The ocean flows keep oxygen levels up and that helps sustain the delicate ecosystem that supports endangered species like the Ridgeway rail. That is a rare bird that only thrives in muddy salt marshes. The bird's habitat is exceptionally green this summer because the estuary was flooded with nutrient rich sewage.

"We learned the hard way how fast this system can go into that sort of condition given the types of inflows that we have," Collins said.

Biologists do not specifically measure sewage or contamination in this habitat, but they do track the estuary's vital signs.

Researcher Jeff Crooks stood on the edge of the estuary and pointed to a post. The pole sits in the channel where open water flows. It is one of several permanent monitoring stations.

Photo caption:

Photo by Erik Anderson

The research station that monitors water conditions in the Tijuana River Estuary every 15 minutes, sending information to a satellite on Sept. 5, 2017

"And you can look and see, there's the little top hat thing that's a satellite uplink so this is being uploaded and we can look at the data in real time," said Crooks, research coordinator at the Tijuana River National Estuarine Research Reserve.

Just out of sigh is a two-foot long tube which contains instruments that dip into the open water. The instruments essentially measure the estuary's vital signs.

RELATED: Imperial Beach Poised To Sue Over Sewage Spills

"So that unit is sitting in there," Crooks said and points as he talks. "And every 15 minutes it's measuring how warm the water is, how salty it is, how cloudy it is, it's measuring water level. Really importantly, it's measuring how much oxygen is in the water."

Plunging oxygen levels recently alerted biologists there was a problem in the estuary. Sand had clogged the opening of the Tijuana River, stopping the intertidal exchange of water. Clearing that blockage gave the estuary a chance to recover. And biologist Brian Collins said recovery is an ongoing battle.

"I know that if we're smart and work with natural systems in ways that are science-based and intelligent, I know we can restore them. It's just a matter of us collectively choosing to invest in that," Collins said.

The estuary ecosystem has proven to be resilient even as it deals with extraordinary challenges. Efforts to control pollution during summer have largely worked allowing the renegade flows to be captured and treated. Even so, there are ongoing battles against invasive species, trash, sediment and those massive rain-driven sewage flows.

"Just in the last three years, there were 300 sewage spills just in the canyons alone. That's one sewage spill every three days," said Imperial Beach Mayor Serge Dedina.

Dedina got so frustrated this past winter that he is now preparing to take the federal government to court. The city announced last month it intends to sue the International Boundary and Wastewater Commission, or IBWC. That is the agency responsible for cross-border sewage issues.

The intention to sue gave the federal agency a chance to respond. Federal officials argued that they are active in the effort to control cross-border sewage flows, but they lack the resources to be more effective.

"The problem is that the IBWC doesn't have money so we need to get this in front of a federal judge and the U.S. attorney's office," Dedina said. "So they can actually sit down and force the IBWC to fix these egregious discharges of toxic waste and toxic sewage in the Tijuana River and canyons, that are impacting our beach and the beach in Coronado."

Imperial Beach has to wait 60 days after announcing the intent to sue before it can file a lawsuit. That deadline is in about a month.

Dedina is urging other cities to join their legal effort.

Coronado has discussed the possibility in at least two closed-door meetings. The Coronado mayor is directing the city council to consider, among other things, drafting a participation agreement with Imperial Beach.

KPBS reached out to San Diego City Attorney Mara Elliott. Her office indicated they have been contacted about the Imperial Beach litigation, however, the city attorney is not ready to make a recommendation to the mayor or city council.

Tijuana River Estuary Endures In Face Of Many Ecological Challenges


Lori Kuczmanski, spokeswoman, International Boundary and Water Commission United States Section



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Erik Anderson
Environment Reporter

opening quote marksclosing quote marksI focus on the environment and all the implications that a changing or challenging environment has for life in Southern California. That includes climate change, endangered species, habitat, urbanization, pollution and many other topics.

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