Army Corps to shore up LA River with 'HESCO' barriers, but what are they?

This week the U.S. Army Corps of Engineers will start flood-proofing sections of the L.A. River by clearing vegetation to improve water flow and lining some of its banks with what's known as a HESCO Bastion barrier.

You may have never heard of the HESCO barrier, but it is a go-to flood control method for the Army Corps.

The thinking is, with more El Niño rains on the way, water levels could jump the banks. These barriers would be crucial for keeping nearby homes  and businesses safe.

But what exactly is a HESCO barrier?

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Imagine a steel wire crate, four feet tall and three feet wide, lined with a plastic canvas and then filled with dirt. Line up several of these in a row and you have a quick and sturdy wall.

The plastic in the canvas is felted, not woven, meaning it’s much stronger than typical construction tarp, according to Aaron Ackley, who works for HESCO and is advising the Army Corps.

"It stretches evenly in all directions when it stretches, that's a key element to prevent runs" he said.

The canvas also has a sort of baked-in sunscreen that keeps ultraviolet rays from degrading the polypropylene in the material. That means the barriers can last five years or longer.

"We want to protect them as long as possible," Ackley said.

The Army Corp plans to lay about three miles of HESCO barrier along sections of the L.A. river between Griffith Park and Elysian Valley.

(This map show the section of the L.A. River the Army Corp of Engineers plans to secure from flooding.)

Crews will be clearing plant growth from high-risk areas of the river around Riverside Drive and the Zoo Bridge, since vegetation can impede the flow of water.

“The flood fighting has just begun for this winter,” said the Army Corps' Col. Kirk Gibbs in a statement.

Unfortunately for joggers, cyclists and walkers, construction teams may close parts of the L.A. River bike and pedestrian path while they place the barriers. The HESCO walls will likely stay up though spring.

The Army Corps of Engineers is providing $3.1 million in federal funding to help secure the river. Every 15 feet of HESCO wall costs about $240.

This style of barrier was developed in the late 1980s by an English coal miner named Jimi Heselden. Heselden later gained fame as the owner of the company that produced the Segway. He died in 2010 after an accident on a Segway scooter.

Aside from flood control, HESCO barriers are very popular with the U.S. Military.

They are used to barricade bases. Larger HESCO walls can even resist rocket propelled grenade attacks.

According to the company that makes them, close to 30,000 miles of HESCO barrier has been used in Iraq and Afghanistan. That's enough to wrap around the entire Earth at the equator.

They are also currently being used by the Army Corp to prevent flooding in Mississippi and Louisiana.