Vernon Smith can smell a sand boil 100 miles away. At least that’s what levee district sandbagger Samuel Williams said Tuesday morning as he lifted the bags to form a barrier around Smith’s latest find.

A crew from the levee district was working on one boil, while Smith waded knee-deep into a lake near Whitehall Plantation, aimed a small red flag and threw it like a dart at the tiny bubbles he saw on the surface.

Smith’s red flags mark the sand boils in need of sandbags.

The crew from the Army Corps of Engineers and the levee district started work early Tuesday to do damage control on 70 miles of levee from Vidalia to Tensas Parish. The number of sand boils, which started at six, and grew to eight after Smith’s checking, is small compared to the 533 found when the Mississippi River reached 56.3 in 1997.

The Mississippi’s waters are predicted to crest at 52.5 on Feb. 1. The river was at 50.3 Tuesday.

Smith, who works with the local Corps office, said the higher the river, the more sand boils form.

The boils form when water from the river pushes through the soil until it forms an opening somewhere on the surface. The danger in the boils is not the water, but what the water removes from underneath the levee.

If not stopped sand boils can cause the base to wash away and the levee to collapse.

The boils can form under lake water or on dry land. When the boil reaches the surface it leaves a pile of sand and materials in a cone shape. Smith said spotting them comes with experience and knowing what to look for.

&uot;I could see the muddy water,&uot; Smith said. &uot;And the white foam circling around.&uot;

The Corps and levee district starts looking for boils once the Natchez gauge reads 49 and they enter Phase 1 flood fighting.

At 53 on the gauge, Phase 2 begins and the engineers and workers do round the clock patrols.

&uot;A lot of effort goes into this work,&uot; Smith said. &uot;In 1997 I lost 30 pounds walking the levees and working around the clock.&uot;

In 1997 National Guard troops were called into to fill sandbags and do manual labor.

The Corps was using prison labor from the Concordia Parish Sheriff’s Office Tuesday.

Laying the bags around the boil is an art, though, Smith said. Williams and a crew of about five other men do the actual laying of the bags.

&uot;It’s a fine art,&uot; Smith said while the men worked. &uot;You don’t want to stop the water flow, but you want to restrict it so it stops the sand.&uot;

The only boils identified so far in Concordia Parish are near Whitehall.