Demonstration-Project DEUS 21: A concept for a sustainable urban water infrastructure

As dynamic as the changes are today in many towns above ground, underground they are often still very conventional: the traditional pipelines and systems of water supply and sewage disposal found today in industrialised countries began their existance in the middle of the nineteenth century. They supply drinking water and water for fire fighting and dispose of polluted water and rainwater. Since it is indisputable that water supply and sewage disposal play a dominant role for each individual and the national economy as a whole, there is the need to find new and sustainable alternatives to today's large-scale centralised structures. Adapted small-scale systems with modular compenents which use the latest technologies represent a promising solution for sustainable water management. Such systems also have application advantages for newly industrialising and developing countries. This paper will describe the innovative concept for sustainable urban water infrastructure called DEUS 21 which is an acronym for the German "decentralized urban water infrastructure system". The DEUS 21 concept utilises rainwater for water supply, and collects residential wastewater together with biogenic kitchen wastes for joint anaerobic treatment. The concept is due to be implemented in a newly developed residential area with about 100 single family homes in the municipality of Knittlingen, Germany, starting in September 2005. The paper describes the concept of DEUS 21, presents the system dynamics based approach to modelling water and energy flows and balances associated with various water infrastructure concepts and given an overview of the appraoch of the sustainability assessment of the DEUS 21 concept in comparison to the conventional approach. The paper also reports on practical aspects related to the planning phase.