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Louisiana builds new land with river mud

August 8, 2006

By Peter Henderson

PILOTTOWN, Louisiana (Reuters) – Louisiana is mining a new
type of black gold: Mississippi River mud.

A pilot project at the river mouth shows how the
hurricane-ravaged state may be able to rebuild its vanishing
coast with fertile river bottom soil now dumped by dredges into
the ocean.

Louisiana continuously clears the bottom of the Mississippi
River to aid navigation, then dumps far offshore sediment that
the river carries from tributaries in more than 30 states.

But recently a dredge clearing a few miles of the river
moved the mud into nearby shallow water, rather than dumping it
off the continental shelf in the Gulf of Mexico.

The result: New terra, though not quite firma.

At the spot where the dredged sediment is being dumped, a
roughly half-mile-square (1.3-square-km) patch of land has
risen and a few wisps of green are struggling to take hold. The
dredge has poured a combination of dark soil and river water
through a pipeline to a monster version of a garden hose that
releases the mess into the shallow brackish water.

Rebuilding such wetlands could help New Orleans absorb the
blow of a future storm like Hurricane Katrina which devastated
the city last year. Congress is considering bills that could
pour a few billion dollars into coastal restoration in the
state.

Louisiana’s predicament is urgent. The state, which has 30
percent of the continental U.S. coastal marshes, is losing a
football-field-sized piece of land to salt water every 38
minutes, according to the America’s Wetland organization.

Human activity is largely responsible. Levees have
prevented the Mississippi River from flooding and replenishing
low-lying areas with silt and fresh water, while salt water has
been invited in by canals cut through the marshes for logging,
navigation and pipelines for the original black gold — oil.

Louisianans have started to notice the loss of the buffer
that the marshes provided. “A tropical storm used to be a nice
breeze around here. Now everybody is flooded by it,” said Dean
Blanchard, conservationist at the Barataria-Terrebonne National
Estuary Program a state-backed group that promotes wetland
conservation.

Ancil Taylor, vice president at Bean Dredging, which
started the pilot dredging project at Pilottown at the mouth of
the Mississippi, argued that using pipelines for redirecting
river sediment was cheap and easy and said similar projects had
been done around the world for decades.

“You just all of a sudden start saving marsh,” he said.
“We’re a Louisiana company, and it breaks our heart to see
these opportunities get away from us year after year.”

MANY IDEAS

But that’s not the only idea on how the state can tackle
the problem. Louisiana’s history is studded with projects that
never took hold. In most cases, after a few years of
inactivity, a new studying process would begin.

Other ideas include building a new outlet branch of the
Mississippi — the $8.7 billion so-called Third Delta that
would empty into some of the fastest-disappearing land,
bringing soil and fresh water to the wetlands. Another idea
calls for redirecting the outlet of the entire river. Finally
there is the plan to build vast pipeline networks that would
expand the current experiment using dredged sediment.

The Louisiana Department of Natural Resources commissioned
a study on the Third Delta idea and alternatives, and the
preliminary results show sediment pipelines would be relatively
cheap and quick — though the total price tag would be steep.

Pipeline projects across southwest Louisiana would cost
between $9.4 billion and $31.7 billion over 50 years. The
biggest version would actually expand Louisiana’s coast, which
the Third Delta would not do over that time, at a cost per acre
of up to $116,000 or a fifth of the Third Delta project,
according to preliminary figures by engineers CH2M Hill.

Moreover, pipelines can start slow and build up, while the
Third Delta is an all-or-nothing project, said department
Deputy Secretary Randy Hanchey.

But he projected it would be 2008 before a state dredging
project might begin. In the meantime, there is still debate in
the state as to the best plan. Sydney Coffee, Gov. Kathleen
Blanco’s adviser on coastal activity, said that the idea of
diverting the mouth of the Mississippi was promising.

“We’ve got to think long-term sustainability,” she said.

That lack of consensus is a warning sign for Kerry St. Pe,
director of the Barataria-Terrebonne National Estuary Program
and a longtime wetlands advocate who is pushing pipelines.

He recently showed off hundreds of acres of solid land
built in the middle of a deteriorating wetlands with dredge
material from a nearby port.

“We need to rebuild land, quickly. And a diversion of the
Mississippi River is not going to do that,” he said.

St. Pe ticked off a half-dozen plans that were made and
abandoned over the decades. His own group’s plan has been
waiting for years, and while he is steadfast in its pursuit, he
is not about to call victory based on recent interest in
wetlands.

“When the estuary plan was created, there was a lot of
momentum. I’d say more than now. It never happened,” he said.


Source: reuters



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