Plaquemines Parish, La. -- The Mississippi River, long held captive within its banks, has broken free in one spot on the east bank of Plaquemines Parish. In the Bohemia Spillway, the river has blown through the river bank and reconnected with an old canal.
"You can see here, the channel is at least 8-10 feet deep right here with a very steep edge," said Dr. John Lopez, poking a stick into the new cut.
Lopez, executive director of the Lake Pontchartrain Basin Foundation, began watching the area along with his staff during the spring flood a couple years ago. Then, on Mardi Gras Day last year, the river plowed through its bank.
"This is a natural process of the river reconnecting itself to the wetlands," Lopez said.
A couple of weeks ago, 2,000 cubic feet per second were pouring through the cut -- enough water to fill an average backyard swimming pool every second.
Lopez, marveling at the power of the river, points to change happening throughout the Bohemia Spillway, on the east bank of Plaquemines Parish below Pointe-a-la-Hache.
"It's the kind of thing that most scientists sit in their offices there, dreaming how it might happen," he told us. "Here, you can actually see it."
He views Mardi Gras Pass as one possible model for coastal restoration, reconnecting the river with the marsh and pushing back the saltwater that's eating at Louisiana's coast.
Lopez points out the state's Master Plan for the coast already includes a diversion several miles down river at a cost of $216 million.
"Here, we have one that is developing for free," Lopez said.
However, not everyone buys into the notion that nature, left to her own devices, has suddenly produced this phenomenon.
"You're not talking about a natural [distributary] of the Mississippi River," said Robin McGuire, vice-president and general counsel of Sundown Energy. "You're talking about a man-made event, a man-caused event."
McGuire notes, in the mid-1970's, man dug the canal as a river diversion, sticking a straw in the Mississippi to feed fresh water into the marsh. Controlled by a small structure with four gates, the diversion had long been abandoned before the 2011 spring flood.
"Nobody wants it," McGuire said. "It's been abandoned and nobody wants to take credit for even having it at one point in time."
Over time, part of the canal stilted in, shutting off the entrance to the river. Then, the Mississippi reclaimed it, making an end run around the control structure and blowing out a road that Sundown Energy uses to access an oil and gas facility.
The company applied for what it thought would be a routine permit to repair the damage. "What we wanted to do initially was put back the road the way it was," McGuire said.
Lopez argues, rather than simply rebuilding a road, they "would be damming a river."
"This is now an extension of the Mississippi River," Lopez said. "It's a free-flowing channel."
Sundown modified its original permit request to include four large culverts, but again drew opposition from environmental groups concerned that the culverts would dramatically cut the flow from the pass.
"These canals that were here are influencing how this is developing," Lopez conceded. "But it is the river that is driving the process."
The Southeast Louisiana Flood Protection Authority-East weighed in, firing off a letter to state officials suggesting they consider partnering with Sundown to build a bridge or some other structure to allow the river to flow.
"We should not try to defeat something that Mother Nature's delivered to us at our door," said SELFPA-East President Tim Doody.
McGuire insists Sundown is not anti-wetlands and would consider some kind of compromise. "We're not opposed to a bridge," McGuire said. "If they want to come in and put up some funds and be responsible, we'll give them the money it would take to build the road."
McGuire said the company might considering putting up addition funds, but he is concerned about potential liability if Sundown builds something on its own.
Altering the fresh and saltwater mix in the nearby marsh might invite lawsuits from commercial fishing interests, especially oyster fishers.
"We're a small oil company," McGuire said. "I don't know who sues us."
Even some engineers question how much value there would be to a diversion that far south, where the river carries less sediment.
Garret Graves, chairman of the Louisiana Coastal Protection and Restoration Authority, said the state is working with Sundown on a possible compromise. However, he said, "As we build more diversions, that's not going to be our best investment of fresh water."
While Mardi Gras Pass flows into a series of canals and bayous, Graves said the site chosen in the Master Plan would spread water more easily over the surrounding marsh.
Graves also raises navigation issues, concerned that if man lets the river run free, it might sometime in the future change course. He points to the West Bay diversion south of Venice, where the U.S. Army Corps of Engineers created a diversion with no control structure 10 years ago.
In the aftermath, Graves said the river scoured down to a depth of 60 feet or more.
In the future, he fears the Mississippi could "make a left turn."
If the state and federal governments decide at some point to realign the Mississippi River, Graves said, "That needs to be a very conscious, very deliberate decision."
Nevertheless, the site is drawing interest given the potential savings.