The flood next time

Photo by Callie Richmond for The Texas Tribune

If President Donald Trump’s wall is built in the Rio Grande Valley, the effects on wildlife in the next flood will be almost Biblical.

Santa Ana National Wildlife Refuge sits in the southern tip of Texas on the Rio Grande, 150 river miles from the Gulf of Mexico. Its 2,088 acres were set aside in 1943 because so much of the thick semi-tropical forest that lined the Rio Grande’s final 250 miles was already gone, cleared for intensive agriculture. It remains an island of original uncleared forest in an area, the lower Rio Grande Valley, that has been cleared of 95 percent of its brush and forest habitat. The decision to protect those 2,088 acres 75 years ago was a gift to the world. For its size, Santa Ana has a greater diversity of plants and animals that any other national wildlife refuge or park in North America, and tourists, more than 100,000 per year, come from all over the world to walk its trails and view its wildlife.

Visitors to Santa Ana walk over a sloping earthen levee as they enter a Spanish Moss-draped forest. The levee, and a similar one on the Mexican side of the river, form part of the floodway system that protects the Valley from floods that were once common before there were dams upstream on the Rio Grande and its tributaries.

Since the floodway system was built and Falcon Dam completed in 1953, there has been only one large flood in the Valley, from Hurricane Beulah in 1967. The only flooding that occurs now is contained safely within the floodway system, and that last occurred in 2010. To make room for floodwaters coming in from Mexico, Falcon Dam had to release huge volumes of water for 68 days. There was water from levee to levee, which put Santa Ana and most other refuge tracts along the river under water, and it took months more for the floodwaters to fully subside.

The effects on terrestrial wildlife couldn’t be measured but were surely severe. Rabbits were seen up in trees. Any animals that could, fled over the sloped earthen levee into farms and fields nearby. Adjacent landowners reported seeing more wildlife on their lands than they could ever recall seeing. Frank Schuster, who runs a large family farm surrounding Santa Ana, lost nearly his entire Blackbuck antelope herd.

“We could tell by the way they were eaten it was bobcats. We were basically feeding Santa Ana’s bobcat population. All their normal prey had either fled or were swept away,” he said. After the flood subsided wildlife gradually returned to the refuge.

Realizing that Santa Ana (and Laguna Atascosa on the coast) weren’t enough to sustain all of the Valley’s wildlife species, another national wildlife refuge, the Lower Rio Grande Valley, was established in 1978. The goal was to create a near-continuous corridor of forest and brush habitat along the river, a corridor that would save room for wildlife, including the endangered ocelot and jaguarondi, alongside a booming human population. Those tracts too, over a hundred of them along the river, were flooded in 2010.

Beginning in 2007, border wall construction had begun, and intermittent sections of the river levee got either a 16-foot-high steel “bollard” fence at the outer toe of the levee, or an 18-foot vertical concrete wall built into the river-facing side of the levee (“levee-wall”). Some refuge tracts were walled-off or were sliced in half, blocking all wildlife access to and from the river. These refuges were particularly hurt during the 2010 flood.

The Monterrey Banco refuge tract downstream from Santa Ana has a half-mile of levee wall. In 2010 there was no way for wildlife to escape the flood. When the water subsided months later, dozens of Texas Tortoise shells were found near the base of the levee wall. Reptiles, mammals, ground-nesting birds and the insect life that sustained them were all gone.

U.S. Customs and Border Protection talks about being good stewards and wanting input on the environmental impacts of Trump’s proposed wall. “They’re just moving their lips,” says Scott Nichol of the Sierra Club Borderlands Team. “It means nothing. If you need any evidence of that, just look at what they’ve done to refuge tracts already and what they’re planning to do to Santa Ana. It boils my blood. It breaks my heart.”

To date, there is no border wall at Santa Ana. But if Trump has his way and Congress appropriates border wall funding, Santa Ana is at the top of the list. It will get three miles of continuous concrete levee-wall, with a 16-foot steel fence on top. No wall design could be worse for wildlife. Nothing will be able to escape the next flood. And nothing will be able to get back in, to repopulate the refuge when the inevitable deluge subsides.

The very refuge that for 75 years has helped assure and sustain wildlife’s survival will become their deathtrap. Noah’s flood lasted 40 days. Santa Ana’s will last much longer. And there will be no ark.

Jim Chapman

Environmental activist