Mara Cordero passes a border fence twice to get to her home in La Posada, one mile north of the Rio Grande, which divides Mexico from the United States. Customs and Border Protection erected the steel beam barrier that cuts through her neighborhood nine years ago, slashing through private property and an ecological reserve.

The Texas resident didnt like it then, and shes not happy that President Donald Trump signed an executive order Wednesday mandating the construction of a physical wall on the Southern border.

The wall is completely illogical, Cordero, a Mexican-born community organizer for the ACLU, told The Huffington Post. We need those billions of dollars for schools and clinics.

Trumps order to greenlight more border barrier, at a projected cost of $16 million per mile , delivers on a central campaign promise in a race that centered on the subject of illegal immigration.

But those who live on both sides of the U.S.-Mexico border, where in many places the wall has been a reality for years, often view it as an impractical and expensive gesture of hostility toward Mexico.

Michael Seifert, a three-decade resident of the Rio Grande Valley in South Texas, lives a mile from the border in the city of Brownsville. Putting up more walls doesnt do much to restrict unauthorized immigration these days because many arrivals now are seeking asylum and turn themselves in at legal ports of entry. And he says hes seen students scale the fence at Brownsville in eight seconds, just to see if they could.

But while Seifert doesnt see any practical benefits to the wall, he sees costs in the undermining of our relationship with Mexico.

Its certainly a symbol of where [Trump] wants to take the country, Seifert told HuffPost. But those of us who live on the border know its bad for business, its bad for relationships. Ive never met a single official who says it works.

Trump defended his order for the border wall at a speech before immigration agents Wednesday, saying that it would improve the U.S. relationship with Mexico by stemming unauthorized immigration.

But Jorge Bustamante, a professor emeritus at Colegio de la Frontera Norte in Tijuana, said it would have the opposite effect.

Its not necessary, said Bustamante, who who specializes in immigration and human rights. Its an ideological issue. The symbolic effect is to present Mexico as if the country were an enemy.

Gilberto Hinojosa, the Texas state chairman for the Democratic Party, lives seven miles from a bridge connecting Mexico to the United States in the Rio Grande Valley. He says he sees a Border Patrol vehicle or bike pass by roughly every 15 minutes. On top of that, state agents from the Department of Public Safety are parked along the road to help patrol the border as part of a multimillion-dollar effort signed by Texas Gov. Greg Abbott (R) last year to crack down on illegal immigration. Theres no question that we have reached our maximum capacity in enforcement down here, Hinojosa told HuffPost.

Like many other border area residents, hed prefer to see the money poured into schools, highways and hospitals.

We cant get industry to relocate to South Texas because theres not enough water, Hinojosa told HuffPost. We cant get industry to relocate to South Texas because theres not an interstate highway. And were wasting our money building a freaking wall that nobody needs or wants?

Rep. Will Hurd, a Republican who represents borderlands that stretch from San Antonio to El Paso, also decried the executive order as wasteful and misguided. Border fencing might be effective in highly populated areas, he said, but rough terrain or protected natural areas present challenges best addressed with a more flexible approach that makes better use of technology.

Big Bend National Park and many areas in my district are perfect examples of where a wall is unnecessary and would negatively impact the environment, private property rights and the economy, Hurd said in a statement.

The El Paso Hispanic Chamber of Commerce took a more diplomatic view. Communications Director Pablo Aguirre said the chamber does not take a position on the issue but hoped that when the fencing gets contracted, local companies will benefit.

We already do have some sort of wall here, Aguirre said. If this is something thats going to happen, we want to see that they get contractors and let them bid on the project and it stays local.

How will Trumps first 100 days impact you? Sign up for our weekly newsletter and get breaking updates on Trumps presidency by messaging us here .

Sign up for the HuffPost Must Reads newsletter. Each Sunday, we will bring you the best original reporting, longform writing and breaking news from The Huffington Post and around the web, plus behind-the-scenes looks at how its all made. Click here to sign up!