New Orleans may let the water back in

As Louisiana struggles with a second huge natural disaster in five years, New Orleans' water management is being revised Dutch style.

Once again, Louisiana has been hit by a natural disaster in which man played a large role. And the damage done by hurricanes and the oil spill in the Gulf of Mexico reinforce each other: the oil slick is making the area even more vulnerable to flooding than it already was. Oil can destroy the marshes on the coast - the last natural line of defence against water. The marshes, that have already been receding for almost a century, also protect the pipelines that transport oil and gas from the Gulf to the refineries on land.

After a massive flood in 1927, the national government began to channel 3,000 kilometres of the Mississippi to make it easier to navigate. As a result, the sediment the river carries is no longer feeds the marshes, but disappears into the deep sea. The US Geological Survey has estimated that some 5,000 square kilometres of wetlands in coastal Louisiana have been lost in the last century, a process hastened by hurricanes like Katrina and Rita.

David Waggonner, an architect from New Orleans, sees more bitter similarities between Katrina and Deepwater Horizon. "It is unbelievable that there was no contingency plan for either situation," he said. "What do we do when the levees fail in New Orleans, what do we do when that one pipe under a drilling rig in the Gulf of Mexico breaks? It says a lot about how blind we are when it comes to water."

A lot to learn

Waggonner is the founder of ‘Dutch Dialogues’, a collaboration between Dutch and American landscape architects, urban planners and engineers that is supported by the Dutch embassy in the US. The architect is convinced that New Orleans, of which 75 percent lies below sea level, has a lot to learn from the Netherlands. Since Katrina, several delegations from New Orleans have come to the Netherlands, and a new group will visit later this month.

Days before the explosion on the Deepwater Horizon that caused the oil spill, designers came together in New Orleans to present new plans for the water system of the city. In their third series of workshops, designers looked at the internal water system of the city. The results were presented at the annual conference of American Planning Association.

The new storm surge barrier built by the Army Corps of Engineers together with the Dutch engineering firm Arcadis has to be finished in June of 2011, before the beginning of next year's hurricane season. Piet Dircke, the director of global water management at Arcadis, has been involved in the Dutch Dialogues. "We want to expand the issue of security with other aspects, such as improving the ecosystem, the experience of water in the city offers and the prevention of subsidence," Dircke said. "Furthermore, we demonstrate that water can add economic value. If the city is safe and attractive, it can draw people and businesses, and the value of property goes up. Residents here believe they need metres-high concrete walls along the outfall canals, but you don't see those anywhere in Netherlands."

One of the working groups has looked into designing these canals without the concrete barriers they have now. Neighbourhoods can be reconnected, people will be able to stroll along the waterfronts and the river bed should be expanded to create green zones that can flood intermittently.

A historical connection

"Do you know what they do here when it rains?" asked Lodewijk van Nieuwenhuijze, landscape architect at HNS. "Everybody gets in their car and drives to higher ground. They wait there for the storm to pass. That is how they keep their car dry. There has to be another way." In New Orleans, Van Nieuwenhuijze said, the water engineering has been put under ground, inside the sewer system. "Soil subsidence breaks the sewers and people solve that by pumping hard, which causes even more subsidence. The land is already a metre lower than it once was and it will subside at least another metre in the next century."

Five years post-Katrina, New Orleans has been rebuilt the way it was, but with even bigger water pumps. "The only change is that insurance companies demand that people build their houses on poles, or a mound. This may be good for the individual owner, but it is worse for the city as a whole. The Dutch belief that these issues should be dealt with collectively hasn't taken hold here."

Another working group looked at reconstructing the connection between Lake Pontchartrain and the French Quarter, via Bayou St. John. "This waterway is the actual birthplace of New Orleans," said Han Meyer, a professor of city planning in the Netherlands. "Here, the Native Americans showed the French they could carry their wares from Lake Pontchartrain to the shores of the Mississippi over water. That lifeline has been neglected: there are beautiful houses along the bayou, but today it is a dead end. If there is one place in this city where there is a historical connection to the water, it is here."

Let the water in

What the participants in Dutch Dialogues want is to create open water at various locations in the city, including parks and people's backyards, to absorb heavy rains and maintain stable groundwater levels in times of drought. One of the working groups suggested doubling the quantity of water in the City Park to keep it in the city's system rather than let it flow to the lake directly; this water storage can also make the city less vulnerable to flooding.

All the proposed measures demand a change in attitude from the citizens and the institutions involved, said Meyer. "Executive fragmentation is an even bigger issue here than in the Netherlands. The Army Corps of Engineers is solely responsible for security and doesn't look at integrated urban water management, that is up to the city to construct, and pay for."

What the initiatives from Dutch Dialogues all have in common is their focus on a measured, controlled entry of water into the city. The remarkable thing about New Orleans is that one knows water is everywhere, but it is nowhere to be seen. The water from the drainage canals is hidden behind walls three or four meters high. The water surface is covered with concrete slabs. The mighty Mississippi flows through the city in a deep concrete trench. There is no way to get near the water, let alone enjoy it from a pleasant public waterfront. For years, New Orleans has sought safety by keeping the water at bay. It will require a whole new mind-set for residents and local politicians to believe their city will be more pleasant and safe if they let it back in.