A Sustainable Water Strategy and New Urban Perspective for New Orleans

Motive

City in the Delta

In 2005, Hurricane Katrina caused extensive devastation in New Orleans. Several key levees broke, and large parts of the city were flooded, resulting in more than 1800 deaths and $81 billion (USD) in damage. After Katrina, considerable effort was put into improving the dikes. Local architects, such as David Waggonner, advocated for the reconceptualisation of the city’s relationship with its natural surroundings and the characterisation of New Orleans as a ‘living city in the Delta’.

Dutch dialogues

In a series of discussions called the ‘Dutch Dialogues’, Dutch water experts and US stakeholders explored the options for a new water strategy for New Orleans. H+N+S were involved in the specialised field of water and design. Though the dialogues, a perspective was developed for the city: flooding would be limited by ample storage space for water (catchments) and water would become a visible, attractive and integrated aspect of the city. Following these dialogues, H+N+S was contracted as part of a US-Dutch team, to develop a concrete Water Management Strategy for the city.

Approach

Integral + Innovative

An innovative aspect of the proposals was the close connection between science, engineering and design. This integrated approach is unique not only for New Orleans, but also by Dutch standards. In cooperation with hydraulic engineers, water issues were quantified accurately and proposals for a monitoring system were developed. The concept for the system was developed jointly and tested interimly , with adjustments made on the basis of results and calculations. Local insights throughout the city were taken into account and integrated in the overall system plan. Specific characteristics of the town and the subsoil were also considered and integrated into the design. From this information and research, comprehensive plans could be formed for the development of individual sub-basins.

Result

Sharing the burden

The new approach positions water as a much more integrated, intertwined aspect of the city, through to small-scale neighbourhoods and individual plots of land. It is at this grassroots level that many of the new measures are necessary and targeted. In the new approach, areas may no longer simply discharge the excess water from their individual plots, but first capture and store it locally, to reduce pressure on the water system. Each part of the city makes a contribution to easing the water problem, and therefore, also actively contributes to the solution.

Delay, store, drain

Pressure on the city drainage system during heavy rainfall is reduced, by creating mechanisms to hold rainwater and let it seep into the ground, before it enters the drainage system. The next step is to locally retain water. Finally, after the water is retained, it can slowly be discharged. In practise, the holding, storage and disposal of water (delay, store, drain) is smoothly integrated into a cohesive system.

Water in the everyday environment

Existing and new water coarses within the city is no longer diverted straight into drainage gutters, but instead forms part of a green network and the basis of an urban ecosystem. The banks of river systems are as green as possible and feature hiking and cycling trails. Streets are renewed and newly profiled to offer plenty of space to slow water movement. Wadis and permeable paving are crucial in this area. The people of New Orleans are also inspired by the new approach of a ‘delta town’ and on private plots, green roofs and rain gardens are increasingly being incorporated.

International team

The Urban Water Plan New Orleans was prepared by an international team under the overall leadership of Waggonner & Ball Architects.

Bosch Slabbers, H+N+S Landscape Architects, Robbert de Koning, and Palmbout Urban Landscapes were responsible for the design, in cooperation with: Waggonner & Ball Architects, Manning Architects, Brown +Danos Landdesign, FutureProof, Bright Moments Geosyntec Consulting, Arcadis, Deltares, Royal Haskoning , TU Delft, City of Rotterdam, City of Amsterdam, CDM, GCR, KBR, Dewberry, Waldemar S. Nelson Engineers, Eustis Engineering, Sherwood Design Engineers.
Supervion by: Han Meyer, Ton Schaap, Lodewijk van Nieuwenhuijze