It's not long — just two pages — but a notice recently issued by the U.S. Army Corps of Engineers is a reminder of the challenges, legal and otherwise, facing President Donald Trump's promised border wall.
The corps issued a notice to contractors Friday saying it soon might accept bids to construct a 3-mile section of border wall in south Texas, with an estimated cost of $25 million to $100 million — if the corps gets the money.
The notice drew alarm from environmentalists, who say the wall undoubtedly will be built on the Santa Ana National Wildlife Refuge. The 2,088-acre parcel has been called "the jewel of the National Wildlife Refuge System" by the U.S. Fish and Wildlife Service,
"The Santa Ana National Wildlife Refuge proposal is truly an outrage," said Brian Segee, a senior attorney at the Center for Biological Diversity. "I don't say that lightly. It will effectively destroy the refuge because the proposed border wall will be built toward the northern part of the refuge so it will cut off not only wildlife, but also ... have ecological, economic and cultural impacts."
The debate over the refuge as a proposed location for a 3-mile section of the wall is a reminder of the complexities that face an attempt to strengthen border security from San Diego to Brownsville, Texas.
Here are some of the difficulties that come with Trump's "build the wall" campaign promise:
How long is the border? How many miles of wall already exist?
The U.S.-Mexico border, which is approximately 2,000 miles, has barriers that block people and vehicles along 653 miles of it, according to the think tank Washington Office on Latin America.
There's no fencing on approximately 1,300 miles of the border, but the Rio Grande forms a natural border along several of those miles. The river, however, can be crossed many ways — sometimes by boat, sometimes by floating on inner tubes. In places where it runs shallow, migrants can wade across.
How much funding has been requested for 2018?
The White House has requested $1.6 billion to build 74 miles of border wall this year, with 60 miles constructed in new areas. The other 14 would replace or enhance existing barriers. Additionally, the White House wants $18 billion for 722 miles of new or replacement wall in the next 10 years, according to WOLA.
Trump said in July there are enough natural barriers along the border that a 2,000-mile wall is not necessary.
"You have mountains. You have some rivers that are violent and vicious. You have some areas that are so far away that you don't really have people crossing. So you don't need that," Trump said. "You'll need anywhere from 700 to 900 miles."
What are the environmental concerns about the wall?
Border barriers have been proposed on local, state and federal lands that have been protected from development to ensure plant and animal populations thrive. The Santa Ana National Wildlife Refuge was established in 1943 to protect migratory birds. Now, 400 bird species, 450 types of plants and half of all butterfly species in North America can be found there.
Overall, there's concern about the impact a wall would have on the wide range of animals that live along the U.S.-Mexico border. For example, jaguars and ocelots have been making somewhat of a comeback in recent years, but the wall significantly would limit their range, affecting their mating and hunting habits, said Javier Sierra, an associate communications director at the Sierra Club.
The wall could keep Sonoran pronghorns and black bears from important food and water sources, especially during drought, according to the Wildlands Network, a Seattle-based conservation group. Additionally, a border wall permanently could divide Mexican wolf populations, leading to a lack of genetic diversity and an increase in the chance of local extinction.
"The wall would be a tremendous disruption in the flow of wildlife throughout not only Texas ... we're talking about the entire 2,000-mile border with Mexico," Sierra said.
What legal challenges has the Trump administration faced in building the wall?
One legal challenge argues that the administration violated the law in its rush to build a border wall and prototype projects near San Diego. Attorneys for environmental and wildlife advocacy groups say the federal government cannot ignore various environmental laws to proceed with the wall project.
A hearing on the case, which consolidates three lawsuits, was Friday in San Diego. Hearing the case is U.S. District Judge Gonzalo Curiel. He did not rule but asked the attorneys for additional information, due Tuesday, and likely will issue a written order later this week.
Curiel is a familiar face to the Trump administration. He presided over the lawsuit against Trump University and was heavily criticized by then-candidate Donald Trump, who questioned whether Curiel could act impartially in the case because he was "a member of a club or society very strongly pro-Mexican." Curiel, who is of Mexican descent, was born in Indiana.
What challenges are there in the location of where the wall would sit?
Building near the Rio Grande presents special challenges. A wall can't be built too close to the river in case of flooding. One delicate issue: Some people own land that abuts the river.
Some portions of a wall would have to be built on private property, prompting many Texans to oppose fencing not just on political grounds (the border area is largely Democratic and Latino), but also because barriers split their land. It's possible someone could own land that's north of the Rio Grande, but south of the border wall — cutting them off from their own property.
To the east in Brownsville, near where the Rio Grande meets the Gulf of Mexico, the federal government seized land in 2009 to erect a stretch of fence on Eloisa Tamez's ancestral home, a Spanish land grant from 1767.
Although she wants the area secure, Tamez complained she had no input before the fence was built and, in an interview with the Times, called it "a monstrosity."
What are the next steps in Washington?
Congress and the White House this month set aside immigration to forge a budget deal. Among the issues still to be addressed is the fate of Deferred Action for Childhood Arrivals, or DACA, the Obama-era program that allowed young people brought to the U.S. as children to live and work legally in the country. Some such immigrants crossed the border illegally, others entered legally but then overstayed visas.
This week the Senate plans an open debate on an immigration bill. Into the mix will be a new idea floated by White House officials: It calls for maintaining legal immigration levels at approximately 1.1 million a year.