Water has been critical to where cities originate their development, and to the standard of living of their inhabitants (L. Mumford, 1961). However, too much or too little water can have devastating consequences (Iain White, 2013). According to Iain White in his article about regional ecology and resilience, maximized use of hard surfaces that generate run-off and by the development of a drainage system made from concrete and designed to move precipitation quickly into the nearest course have been the conventional strategies that are actually risky for our urban environment. Opportunities for infiltration and evaporation would be minimized, since many of the times, green spaces have been significantly sacrificed due to intensive development growth.
Jenfelder Au is a future sustainable project within the frame of IBA projects in Hamburg that showcases a small scale green neighborhood model, which strongly implements water sensitive urban design (WSUD) approach in its forward thinking planning. Located in Jenfeld, a district in East Hamburg, the site formerly functioned as Lettow-Vorbeck Barracks. This project, which planning is designed by West 8 through competition, illustrates solutions to protect the neighborhood’s natural resources, as well as make it becomes more climate resilient in the future. The main focus and feature of Jenfelder Au is sustainable water and energy management. According to IBA, The municipal infrastructure enterprise Hamburg Water would like to implement the drainage concept „Hamburg Water Cycle“ for the first time on a grand scale and incorporated into newly constructed buildings.
Rainwater, black water (from toilets) and grey water (remaining waste water) will be collected in segregated form and used. All households will be equipped with vacuum toilets, enabling the entire collected black water to be fed to a biogas plant. The biogas thus gained will be used to generate heat and electricity for the new district in a local heat and power station having a neutral effect on the climate (IBA).
The site planning layout encourages the cycle of rainwater to be closer to the natural one, where evaporation and groundwater infiltration are possible due to the project’s lavish greenery and perforated streetscape design. The project introduced a decentralized drainage system in a form of landscape and waterscape features, in order to collect and flow most of rainwater directly into the main retention pond in the middle of the site, which will retain water longer rather than let it lost as run-offs. It is a method where both urban surface water and groundwater can be regenerated and replenished naturally, while water pollution and clogging can be minimized. Water harvesting system is incorporated not only in the landscape design, but also in the building design, to create an enclosed system where as much water resource as possible could be reused.
In total, about 770 easily accessible residential units (single family homes, duplexes, terraced houses, and town houses, as well as multiple family dwellings) are planned to be built on a well developed site area covering more than 10 hectares of land. Approximately 4.5 hectares of land are provided for commercial sites, to provide shopping amenities to the neighborhood within a radius of 400 m to 1.2 km. Elementary and secondary schools are also going to be provided nearby the residential area.