East Grand Terre, Louisiana (CNN) -- On a coastal barrier island off the Louisiana coast, several bulldozers are busy spreading sand, building land where there once was water.
Construction of emergency sandbars to protect the state's shores from oil is expected to begin later this week, Louisiana Gov. Bobby Jindal said.
An existing beach restoration project already shows the construction techniques that are likely to be involved.
At the tip of East Grand Terre Island, a giant pipe comes out of the sea and snakes across the beach. It ends in a 90 degree angle, sending a geyser of sand and seawater erupting into the air. Buzzing around that geyser, several bulldozers with their tracks half underwater are pushing the sandy mud, spreading it out to form a new embankment.
A journalist arriving by boat, landing on the new beach, finds the sand is squishy under the toes.
The sand is dredged from the seabed far offshore -- where a barge dangles a giant hose into the water -- and is pumped as far as a mile through metal pipes to reach land. A string of buoys, laid out like bread crumbs, marks the underwater pipeline.
To keep it flowing, the sand is mixed with seawater at a ratio of 75 percent seawater to 25 percent sand.
The East Grand Terre project was started long before the BP oil spill began, as part of a long-term coastal management plan. But it could serve as a model for the new construction.
Elected officials, including Jindal, have pushed the idea, saying building the sandbars -- also referred to as berms -- would protect the inland bays and marshes by collecting oil on the sandy beaches, which are easier to clean up.
But there are also several drawbacks to the project, experts caution. The dredging could contribute to erosion of the area's already-depleted coast; the barriers could affect fish by changing the water's currents or salinity; and the six-month work could be finished so late that it doesn't do much good.
On top of that, a hurricane could undo in a day what took months to build.
But given the risk of the damage that unchecked oil could do to wetlands and inlets, state officials are pressing ahead.
"There's always upsides and downsides," said Coast Guard Lt. Cmdr. Dan Somma. "This sand naturally moves, because these are natural barrier islands. So during a hurricane, these sands would be moving naturally anyway. This process just speeds that along."
BP has agreed to pay up to $360 million for the construction, and after weeks of pressure from Jindal and others, the government has approved much of the plan.
"We've said all along, either help us or get out of the way," Jindal told CNN this week. "We didn't wait for BP. We're moving equipment. You'll see dirt moving this week."
CNN's Brian Todd contributed to this report.