By Diederik van Duuren, Dimitrios Bouziotas and Henk-Jan van Alphen
Neighborhoods typically rely on large centralised systems for their drinking water provision, storm water management and wastewater disposal. However, this dependence could be replaced by a decentralised model that promotes a new, circular path for water. This new path supplements central infrastructure with an array of decentralised technologies that aim at making the neighborhood smarter, more resilient, climate change-proof and able to utilise local water resources. By introducing a modeling framework for circular water neighborhoods, this new path can be modeled in an integrated way, and beneficial effects across multiple urban water cycle domains can be evaluated, including drinking water consumption, wastewater generation and storm water retention. A recently published study by KWR and WML, which is featured as a cover article for June in the journal Water, describes such a framework. The developed framework is based on a simulation model and features key performance indicators that evaluate the performance of integrated decentralised solutions at multiple water cycle domains, conveying useful high-level information to stakeholders.
The demonstrated framework is applied to provide an ex ante evaluation of the design options of SUPERLOCAL, a newly developed area in Limburg, the Netherlands. This area is being (re-)designed as a circular, water-wise neighborhood, where multiple decentralised technologies are combined. SUPERLOCAL is a circular transformation project in Kerkrade that will consist of 130 households. A so-called closed water cycle is designed and will be implemented in 2020 in order to adapt to climate change, address resource scarcity and enhance interaction between neighbors. The social housing corporation (HEEMwonen), municipality of Kerkrade, water utility (WML) and waste water authority (WBL) collaborate closely in this project.
What is different in this local water-wise neighborhood from conventional neighborhoods? Firstly, rainwater will be collected and stored to prevent runoff and floods. Some of this rainwater will be treated to drinking water standards in a decentralised, modular treatment plant, in order to cover part of the neighborhood demands. Secondly, households will use less drinking water due to the introduction of different water-aware, in-house technologies. Besides water saving, these technologies also help separate the wastewater streams: vacuum toilets (use only one litre per flush) and food grinders (not common in the Netherlands) produce a black water stream, which can be converted to biogas and fertilisers. Also, different types of water-saving showers will be tested, which produce grey wastewater that will be treated in natural helophyte filters. This treated waste water will be tested for different reuse purposes such as a common laundrette and, alternatively, as a source for producing drinking water.
Co-creation of knowledge
This modelling framework is part of a larger BTO WiCE project where KWR, together with the SUPERLOCAL partners, develops a methodology to evaluate the performance and impact of this innovative neighborhood. Mapping the multiple values created, as well as assessing and evaluating results, have been central points of this process. The model that is created based on this study can be used during the following years to evaluate the impact of the project and translate it to understandable information for laypeople. Furthermore, this model makes it possible to calculate different scenarios and to test different system configurations and scales. This will provide insights which hopefully will be evaluated in other BTO WiCE projects. The approach developed in this project can also be useful for the development of other water-wise neighborhoods. The close collaboration between research and practice partners in this project shows how the co-creation of knowledge contributes both to scientific understanding and the practical realisation of water-wise neighborhoods.
- Journal Towards Circular Water Neighborhoods: Simulation-Based Decision Support for Integrated Decentralized Urban Water in Library KWR
- WiCE on kwrwater.nl