WETLAND RESTORATION GOT UNDER WAY in earnest last winter at Tijuana Estuary, just north of the Mexican border at the town of Imperial Beach. A new 1,000-foot-long tidal creek and intertidal marsh, the Oneonta Tidal Linkage, now connects two previously separated wetland areas in the northern part of the 2,500-acre Tijuana River National Estuarine Research Reserve. It was built to improve tidal circulation in about 200 acres of the estuary's least disturbed and most productive wetland complex, known as Oneonta Slough.
The Oneonta Tidal Linkage is a small pilot project for a much larger estuarine and intertidal wetland restoration program planned for an area south of the Tijuana River mouth. Nearly 500 acres of former salt marsh will be brought back in a multiphase program first outlined in the early 1990s. Working under the auspices of the Reserve, the Coastal Conservancy is coordinating this undertaking with several partners, including the U.S. Fish and Wildlife Service, San Diego State University's Pacific Estuarine Research Laboratory, and the local nonprofit Southwest Wetlands Interpretive Association.
The pilot Oneonta Tidal Linkage is anything but ordinary. It was planned, funded, and built by a Conservancy-coordinated team of wetland scientists, land managers, and environmental educators. Unconventional construction methods were used, including a dredge afloat on a temporary artificial pond and a mile-long slurry pipeline that transferred silty sand from the project site to the ocean surf zone, to nourish the depleted barrier beach.
Hemmed in by a tangle of environmental regulations, including severe seasonal restrictions aimed at protecting nesting conditions for the endangered light-footed clapper rail, the project was so demanding that many wondered whether it could be built at all. It was finally completed in midwinter, largely on schedule, within budget, and with only minor snafus.
An extensive horticultural dimension is part of this project, including a research site with experiments designed to answer a number of questions about the requirements for re-creating a natural regime of marsh flora. Although the sun-drenched winter helped with the channel excavation, it presented challenges for project horticulturists. Such challenges were anticipated, however, and temporary irrigation proved invaluable.

Jim King begins his tenth year of work as the Coastal Conservancy's representative at Tijuana Estuary. He remains patient and optimistic.

Two Nations Meet on a Troubled Creek

The Coastal Conservancy's proposal for a binational project to address erosion and sedimentation in the 4.6-square-mile Goat Canyon/ Cañon de los Laureles watershed is a step closer to reality. As reported in last summer's Coast & Ocean (Vol. 12, No. 2), this small creek is the westernmost tributary to the Tijuana River, originating in the coastal hills above Tijuana's La Playa district, just south of the border. Destructive floods and soil loss in the watershed had become chronic, and conditions continue to worsen.
The U.S. Environmental Protection Agency (EPA) has proposed providing the Conservancy with a $55,000 "start-up" grant for a project that will look at erosion control and stormwater management solutions in this Tijuana River subwatershed, both in the United States and in Mexico. As this issue of Coast & Ocean goes to press, the Conservancy is set to consider at its July meeting whether to accept the funding and to authorize staff to proceed with the work.
This project would be among the boldest initiatives yet undertaken by the Coastal Conservancy in the interest of Tijuana Estuary's beleaguered wetlands. It is likely that the Conservancy will work with a unique group of dedicated organizations, including several offices of the EPA, the California State Parks Department, the International Boundary and Water Commission, the Municipio de Tijuana, the Colegio de la Frontera Norte, the Border Environmental Education Project, and the San Diego Natural History Museum.
Goat Canyon Creek flows from Mexico directly into Tijuana Estuary's south arm. In big winter storms, great waves of sediment wash down into the wetlands, filling them in. Staff have long contemplated actions to control sediment flow, both from the U.S. and from Mexican sources, with a "hands-across-the-border" project. With the successful completion of the Oneonta Tidal Linkage, which has provided valuable experience in multipartner collaboration, the time may be ripe for such a binational project. Look to upcoming issues of Coast & Ocean for further news. --J.K.

What's So Important about This Estuary?

The estuary has a sullied reputation, based on a very real, very troubled history. Now, though, much of the pollution that once overwhelmed parts of the estuary is controlled, and the sad games of the Border Patrol and the illegal immigrants are played out mostly to the east, in the Otay wilderness and other inland areas. Except for the almost constant presence of thumping helicopters, the estuary is a very quiet and truly serene place (The helicopters are not associated with the border, but part of the age-old U.S. Navy helicopter training facility just next door, at the Imperial Beach Landing Field).
Tijuana Estuary is important to naturalists because it's been left alone. While much of the landscape does look scruffy, and big areas of prime salt marsh have been lost to silt and sand, large intact remnants of several different habitats once common to the southern California coast can still be found here. There's no Pacific Coast Highway here, no railroad, no bridge across the estuary, no high-speed roads of any sort.
By some measures, the habitat here is more intact than anywhere else in coastal southern California. Intertidal wetlands join large tracts of willow-dominated riparian forest where the National Wildlife Refuge and Tijuana River Valley Regional Park meet. These, in turn, have not been cut off from the remnant coastal sage scrub communities on Spooners Mesa and the other highlands that border the valley to the south. And perhaps most surprising, native dune habitats--rare anywhere in southern California--still exist along the barrier beach, although the dunes themselves have been reduced to a fraction of their historic size.
Wildlife thrives in Tijuana Estuary and its surrounding natural areas in a classic demonstration of the interdependence of all these ecological types. There are buffer areas and areas for retreat during times of flood; there's food in times of drought. For a lot of species there's elbow room at the Estuary, unlike anywhere else on the urban southern California coast. Imagine how fragile it all is. Seasonal closures are designed to protect sensitive habitats and can affect trail access. Check in at the visitors center for information and a listing of interpretive programs.
--J.K.