A new study confirms the Atchafalaya River's sediment has stabilized much of the eroding wetlands just west of Terrebonne Parish.

But, lacking such a natural resource, Terrebonne, Lafourche and areas to the east are losing wetlands at an alarming rate.

What's new about this latest study, conducted by Louisiana Sea Grant, is a map that shows just how alarming the loss has been. Since 1932, it shows, the Gulf of Mexico has crept at least 10 miles closer to Houma. That fact is not surprising, but when you see just how much the Gulf has advanced, as indicated on the map, the urgency becomes crystal clear.

Among problems that become immediately apparent:

• Louisiana has lost its historic boot shape because almost all of the wetlands that formed the peninsula around the Mississippi River as it heads through Plaquemines Parish on its way to the Gulf are gone. Scientists, politicians and coastal advocates have discussed in the past changing official maps to reflect the change. For accuracy's sake, that probably ought to happen.

• Cocodrie is a beachfront community now -- any wetlands that once separated it from the Gulf have vanished, if not literally then at least functionally. Port Fourchon and the south Lafourche levee system have little buffering them from the Gulf either.

• One of the greatest threats to Houma is now less than 10 miles away. Locals call it Lake Boudreaux, but it has mostly become an open expanse of water leading directly to the Gulf.

All is not lost -- at least at this point. The Morganza-to-the-Gulf hurricane-protection system, along with south Lafourche's levee, are providing important flood protection to inland communities, and work is underway to strengthen both.

Louisiana's $50 billion, 50-year coastal master plan includes eight river diversions across the state, including two designed to benefit Terrebonne and Lafourche.

One $196 million project would channel more fresh water down Bayou Lafourche in an effort to keep salt from the Gulf out of the area's drinking water and nourish eroding wetlands. That project advanced last week as the state announced it will soon begin building a pump station where the river meets the bayou.

Another project will include a sediment pipeline and diversion of the Atchafalaya into western Terrebonne. The plan estimates the two projects, which would cost $681 million combined, would reduce land loss by 13,500 acres.

The latest study offers guidance as the state navigates a plan to save coastal communities like Terrebonne and Lafourche from vanishing into the sea. It makes the case that massive river diversions are essential, something scientists, coastal advocates and others have debated for years. And, for residents who still think they can stay high and dry and let the next generation deal with the problem, it includes a map that shows otherwise.

-- Editorials represent the opinion of this newspaper and not any single individual.