Cordova Island

 

“This day will be remembered in El Paso as ‘Flood Friday’. Just after dinner an alarm sounded to warn the town that the canal banks had broken. . . . The lower part of town is at the mercy of the flood. Tonight there must be in the neighborhood of 3,000 people homeless.”
—Richard Fenner Burges, May

El Paso Public Library

As a naturally flowing river, the path of the Rio Grande was continually shifting through gradual processes of erosion and deposition as well as quick changes from flood waters suddenly carving out a new channel (known as avulsion).

In the Convention of 1884, Mexico and the United States reaffirmed the river’s deepest channel as the international boundary. For the first time, the new treaty also acknowledged the river’s changing course. If the river channel moved gradually over time, the boundary moved with it. If the river shifted suddenly, the boundary remained along the previous course.

By the 1890s, the Rio Grande made a dramatic bend that caused flooding in both El Paso and Ciudad Juarez.

In 1899, engineers from both countries dug a channel across the bottom of the meander to reduce the impact of flooding. The international boundary remained along the former riverbed. This left an “island” of Mexican land jutting north into US territory.

 

 

The International Boundary Commission placed 19 monuments around the perimeter of Cordova Island to mark the international boundary. During American Prohibition in the 1920s-30s, the area attracted drinkers and cross-border smugglers. In response, Mexico erected a fence along the perimeter in 1940.

As US and Mexican negotiators drafted the terms of the Chamizal Convention, sketched the path of a new channel that would be a clear boundary with the United States to the north and Mexico to the south. Instead of following the boundary around Cordova Island, however, the straightened channel cut the area in half. The northern half was transferred to the United States, and an El Paso neighborhood further east was transferred to Mexico to compensate.

 

Aerial view of Chamizal zone showing the planned relocation of the Rio Grande in blue and the lands to be transferred (630 total acres to Mexico and 193 acres to the United States) to implement the Chamizal Convention of 1963

University of Texas at El Paso Library

 

Today, the part of Cordova Island now in the United States comprises Chamizal National Memorial, the Bridge of the Americas port of entry, and Bowie High School.