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Rapid Growth, Border Fence Threaten Fragile Tijuana Estuary

When it comes to environmental issues, living in the border region poses a unique set of challenges. The Tijuana Estuary's environmental health has been a source of contention between our two countrie

This segment originally aired November 27, 2006.

When it comes to environmental issues, living in the border region poses a unique set of challenges. Case in point: the Tijuana estuary, which runs along the U.S.-Mexico border. Its environmental health has been a source of contention between the two countries for decades. But now it’s viewed as a model of cross-border environmental cooperation. Independent producer Marianne Gerdes takes a look at the threats to this fragile and valuable estuary habitat, and how both countries are working to save it.

The Tijuana Estuary is one of the most complex pieces of real estate in San Diego County. It’s a salt-water estuary, a breeding ground for ocean-going fish and birds, a research center for biologists, and, it sits on the front lines of border security with Mexico. 

This six and a half-square-mile marsh is among the most biologically productive ecosystems on earth. It is also one of the most polluted.

Tijuana, a city of a million and a half residents, sits on the hills and canyons that drain directly in to the estuary. Polluted run-off inundates the marsh during the rainy season, and has kept the communities of San Diego and Tijuana at odds for decades. 

Oscar Romo: What we now call problems is just a natural process that happens when two areas are related to the level. The flows from the Tijuana River watershed have to end up somewhere and that somewhere is across the border right here.

Historically, the problem has been sewage run-off. Tijuana grew faster than municipal services could keep up. But beginning in the 1990s, growth reached unprecedented levels. 

NAFTA brought thousands of new jobs to Tijuana and attracted migrant workers to fill them. Today, 1.6 million people live in the city.

Paul Ganster: Tijuana is growing at an annual rate of five to six percent, it’s population is doubling every twelve to fifteen years, 80 to 90,000 people arrive every year. Paul Ganster: Mexico is making a great effort to manage pollution, but it’s a very difficult job to keep pace with the demand for services much less keep ahead of the demand.

Oscar Romo: The Tijuana authorities are trying, but they don’t have the resources. Only a couple of cents from every peso that the city collects in taxes stays in Tijuana, the rest goes to Mexico City to support some other projects.

This is Punta Bandera, Tijuana’s largest sewage treatment facility. At U.S. insistence, this facility was built ten miles away from the fragile border estuary. More than half of the city’s raw sewage is treated at this state-of-the-art facility. 

Hector Valarez: We have about seven treatment plants along with Tijuana, and those plants treat 95 percent of water collected. Two years ago, it was updates from 750 liters per second to 1,100 liters per second right now. So we are looking to reuse so we can discharge a small amount of the water into the ocean as we possibly can. 

It’s more expensive for the city of Tijuana to pump and treat its waste so far away from the source. But the effort drastically reduces the sewage problems in the estuary.

The real threat to the survival of the estuary comes from these ramshackle colonias that have sprouted out of the hillsides to house the city’s ever-growing population.

This is Los Laureles Canyon, directly upstream of the Tijuana Estuary. Dozens of canyons like this one surround Tijuana. 

In the winter, rain-swollen run-off containing tons of sand and silt from these canyons runs down the hillsides and crosses the border, literally choking the estuary below.

Clay Phillips: Sediment laden material came down from Mexico, blasted through the road and came upon this area that used to be salt marsh and now is covered by five feet of fill. Imagine the road was three feet above this area and now it’s two feet below. Not only is this lost estuary habitat, which is very significant, but it also means that whenever it rains, this road is the low spot, it’s where the water collects. So the whole problem of sedimentation also affects the public’s enjoyment of this beautiful spot.

The City of Tijuana is changing its development practices. New, affordable housing units are springing up by the thousands, built using best management practices adapted from the U.S. construction industry. On the U.S. side, sediment basins at the upper end of the estuary capture sand and debris before they reach low land.

Clay Phillips: The problem is, so much sediment comes out of Mexico these sediment basins will never be big enough to handle all the sediment.

Restoring the saltwater estuary costs the U.S. taxpayer between 100 and 500,000 dollars an acre, a small fraction of the tens of millions of dollars that have, and will continue to be spent to preserve this one saltwater marsh.   

That such great beauty and biodiversity manages to survive at all is remarkable. It’s an example in international environmental cooperation with a simple message: that helping your neighbor is the best way to help yourself.

Oscar Romo: There’s definitely a benefit by investing some of U.S. resources in Mexico, it’s in the best interest of California. The water flows this way, the sediment flows this way, the trash as well. So why not help your neighbor to solve your problem.

With so many millions of dollars invested to preserve and protect the threatened marsh, it’s ironic that the U.S. government may be the source of the estuary’s next big threat. The fortified border fence project will introduce a major construction to the estuary expected to add to the sediment flow and further damage the fragile habitat.