Officials at the U.S. Army Corps of Engineers say they're making progress on repairs and improvements to the levee system protecting New Orleans from hurricane storm-surge flooding. USA Today reports that contractors for the Corps are working double shifts to boost the levees' capacity to handle this year's possible crop of storms ("Army Corps: Flood work around the clock in La.," by Cain Burdeau, Associated Press writer). The Times-Picayune covers the story in more detail ("New Orleans region's levee system is making strides," by Sheila Grisset). The Corps has spent $2.5 billion on levee work since Hurricane Katrina hit in fall of 2005, and has another $8 billion on tap for further construction. But all the planned improvements will not be in place until 2011 — and even then, the system will fall short of protecting against some possible hurricane strikes. In any case, officials say, the system is designed to protect property, not life. So even when the levees are finished, south Louisiana and New Orleans residents should heed evacuation warnings and leave the city if a dangerous storm approaches. Westward along the Gulf coast, meanwhile, there's discussion of a whole new system to protect the city of Houston and its vital port facilities — along with the barrier island of Galveston, the Bolivar peninsula, and low-lying mainland rural counties. Dubbed the "Ike Dike" after last year's Hurricane Ike, which drowned much of the Bolivar Peninsula and parts of Galveston, the proposed structure would consist of elevated levees along the edge of the barrier island system, plus moveable floodgates across the shipping channel that allows entry to the Houston harbor. The idea is the brainchild of University of Texas oceanographer William Merrell, who got his inspiration from the civil engineering works that protect the low-lying Netherlands against the waters of the North Sea. Merrell pitches his concept in a Dallas Morning News editorial ("William Merrell: Why Texas needs the 'Ike Dike' ”). The Wall Street Journal also covers the story ("Planning the 'Ike Dike' Defense," by Ben Casselman). Ike's destruction, impressive though it was, could have been multiplied tenfold or more had the storm veered just a few miles to the west and pushed its surge up the waterway toward Houston. In that scenario, instead of flooding a sparsely populated island and some barely inhabited swamp and range land, the surge could have knocked out shipping facilities, petroleum refineries, and chemical plants that play a significant role in the national economy — along with the homes of a quarter million or more people in the seaward portions of Houston and vicinity. Proponents say the Ike Dike could block such a wave, potentially saving many more billions of dollars than the project would cost to build.

But the actual costs for a project that is still at the early idea stage are impossible to guess. And some detractors say that the project could even cause additional flooding in some situations, by trapping water behind it. Critics also point to potential environmental impacts, and they say the project could distract from simpler, less costly measures to reduce storm impacts by modifying individual sites and buildings. The basic engineering to accomplish the project, however, would not be an innovation. Proponents say the job could resemble floodgates installed at Rotterdam in the Netherlands in the 1990s, or a flood-protection system currently nearing completion at the Russian city of Leningrad, on the Baltic sea. And Houston is not the only American city considering similar flood defenses: New York City is a possible candidate for a similar seawall, intended to protect the city's low-lying boroughs from the kind of flooding that inundated Manhattan during an 1821 storm that flooded what is now the city's financial district. Ideas ranging from a series of short barriers at critical points, to a 5-mile-long wall extending from New Jersey to Queens, were raised at a March conference that drew 100 scientists and researchers to the New York University's Polytechnic Institute, according to an Associated Press report ("Hurricane barriers floated to keep sea out of NYC," by Jennifer Peltz). Ike Dike supporters say one way to fund at least part of the project could be to build the wall along the route of existing seaside roadways, tapping Federal highway dollars. And with Houston business interests, including the powerful chemical and petroleum industries, warming to the idea, the Ike Dike may prove to be politically viable. Says local politician Bill King, who served on Texas Governor Bill Perry's post-Ike hurricane commission: "This actually has more political legs than I ever dreamed it would have."