"A group of American and Dutch architects and urban planners will meet in New Orleans this week for a third session aimed at finding ways to better incorporate water into the city's effort to rebuild more safely after Katrina.
The participants will focus on a segment of the city stretching from the Lafitte Corridor abutting the French Quarter -- an abandoned railroad right-of-way that was once the site of a canal that connected the Quarter to Bayou St. John -- to the lakefront, including City Park and a section of Gentilly.
But in the 20th and 21st centuries, New Orleanians shut itself from the water, hemming in the Mississippi River with levees and draining the backswamp with massive pumps and drainage canals that hid the water from view.
The planners hope to spur redesigns of sections of the city where waterways, urban wetlands and green, open areas can be used to store additional rainfall or where developed areas are redesigned to better hold rainwater through use of new absorbent street and sidewalk building materials or adoption of cisterns and other water-storage containers.
Planners from the Netherlands will share their knowledge of similar efforts adopted in that country, with a recognition that differences in New Orleans' geology and climate will require significant adjustments.
Former wetlands on which Gentilly and other suburban neighborhoods were built used to keep the city's geology buoyant, Waggonner said. Today, vast areas of the city have sunk to as much as 6 feet below sea level, the unintended result of those areas being drained by canals that suck up the water that had kept the soil elevated.
The trick, he said, is to find ways of reintroducing water into soils in ways to reduce subsidence, and in finding ways of transforming the canals into spaces attractive to the public.
Alternatives could include the adoption of plans already backed by state and city officials to turn the London and Orleans avenue canals into a gravity-fed drainage system by building permanent pump stations at the lakefront that would replace existing interior pump stations.
The Army Corps of Engineers already has decided to build a combination gate and pump station on the London Avenue Canal that would operate only in the event of a hurricane, and would pump in tandem with the existing interior pumps. However, its design for that and two other stations on the 17th Street and Orleans Avenue canals allow the stations to be adjusted if the gravity-fed system is adopted in the future.
New islands along Lake Pontchartrain could assist in reducing the risk of storm surge and protect levees, planners say.
The designers also will study ways to redesign the flow of water in City Park to allow storage of more water during storms, while also providing more access to water habitats for the public, similar to the use of canals in Amsterdam and other Dutch cities, Waggonner said.
In perhaps the most radical concept, the planners will look at ways to develop new islands along Lake Pontchartrain that can assist in reducing the risk of storm surge and protect levees, while adding public parks and green space to the city.
Sponsors of the dialogue include the Royal Netherlands Embassy in Washington, D.C., the Netherlands Water Partnership, Waggonner & Ball Architects and the American Planning Association."