SAN DIEGO (KGTV) - Construction on border wall prototypes is set to begin along the U.S.-Mexico border in the South Bay.

Work on eight, 18-30 feet-high wall prototypes, four made of concrete and four made of other materials, started in Otay Mesa Tuesday and should be completed within the next 30 days, according to U.S. Customs and Border Protection (CBP).

Via de la Amistad is closed down just east of Enrico Fermi Drive. About a mile and a half from there, in a dirt lot, is where construction of the prototypes will go in.

Watch Live: U.S. Border Patrol discusses border wall prototype construction:

U.S. Border Patrol to discuss border wall prototype construction WATCH #LIVE: U.S. Border Patrol to discuss the beginning of construction of border wall prototypes. MORE DETAILS: http://bit.ly/2hxmibe Posted by 10News ? ABC San Diego KGTV on Tuesday, September 26, 2017

The San Diego County Sheriff's Department will be patrolling the "free speech zone" once the location is established, according to the U.S. Border Patrol.

A fence was put up around that area recently, plastered with signs telling people to keep out. It’s about eight feet tall and work on the prototypes will begin behind it.

Construction on 8 wall prototypes began today in San Diego. The prototypes are designed to deter illegal border crossings. (1/2) pic.twitter.com/WB1rIojgLj — CBP (@CustomsBorder) September 26, 2017

Signs posted on Via De La Amistad show that the street will be blocked off from September 26 until November 10.

"We are committed to securing our border and that includes constructing border walls. Our multi-pronged strategy to ensure the safety and security of the American people includes barriers, infrastructure, technology and people," Ronald Vitiello, acting CBP deputy commissioner, said in a release. "Moving forward with the prototypes enables us to continue to incorporate all the tools necessary to secure our border."

Tuesday morning, the San Diego County Board of Supervisors passed an urgency ordinance allowing the ability to prohibit items known to be used as weapons (such as knives, shields, rocks, clubs, pepper spray, firearms, sticks, etc.) to be brought into defined areas. The ordinance takes effect immediately.

If the ordinance is enacted, the exact location and what is being restricted will be posted online at least 24 hours in advance. The penalty for violating the restriction could include a misdemeanor and/or fine up to $1,000.

In a vote of 4-0, the board passed the ordinance to address the possibility that "persons intending to engage in conflict and non-peaceful conduct may participate in these [protests] and these persons may be equipped with items intended to be used as weapons," referencing other high-profile protests that have led to violence in recent months.

Another ordinance was approved Tuesday by the board allowing the San Diego County Sheriff's Department to temporarily close off streets in unincorporated areas of the county if "necessary for the safety and protection of persons" using that area for travel.

A new ABC News poll reveals that 62 percent of Americans say they’re against a U.S. border wall with Mexico, while 37 percent are for it.

Local activist and founder of the group Border Angles, Enrique Morones, is against President Trump’s border wall plan, but encourages free speech on both sides of the issue.

Morones is concerned about the potential violence from any groups that could be coming from out of town or out of state and counter-protestors.

“A lot of people want to make their feelings very clear on both sides,” said Morones. “That’s what freedom of speech is all about. But not violence, not violence.”

Six companies will build a total of eight wall models. Half will be made of concrete, the rest will be made up of “other materials.”

“We just had an event a little while ago, in which we had people from the FBI, sheriff’s office, police, border patrol, and at that event I mentioned how worried all of us are about these protests that are going to be taking place because of the prototypes that are going to be built at Otay Mesa,” said Morones.