Nieuwegein Circular Water

Technology

Water is often taken belatedly into account in the planning process for the sustainable development of a newly built area. Opportunities are missed as a result. This could for instance involve creating the possibility for the longer retention of rainwater, the separation of wastewater streams, and the re-treatment and reuse of water streams in the district itself for its own purposes.

The municipality of Nieuwegein’s main ambition is to create an attractive district with plenty of green. In the Nieuwegein Circular Water project we are developing techniques to take optimal advantage of the water-use opportunities, and to find solutions for dealing with water-quality risks associated with the (re)use of water streams.

Challenge

The challenge is to design a water system that satisfies the following wishes:

• Circularity: whereby enough water remains in the area so that water demand and supply are matched; and whereby water is reused as responsibly as possible and water streams are separated.
• Climate-adaptiveness: we are realising a system that is capable of processing extreme precipitation and, in dry periods (such as in 2018 and 2019), can help meet the water requirements for urban green spaces and other functions. The water can in this way also contribute to reducing heat stress.
• Visibility: water contributes significantly to the city experience and makes the living environment more pleasant (cooling, high appreciation).
• Development of a blue/green environment: water buffering (on roofs, façades, in the ground and the deep subsurface, public spaces, buildings) offers the option of having water available for the city at times of water scarcity (green roofs, green courtyards, public urban green spaces, etc.).
• Recognition and management of water-related risks:
  – microbial safety;
  – chemical water quality (preventing contaminants such as pharmaceutical residues from ending up in the environment);
  – flood prevention.

Solutions

The Nieuwegein Circular Water project revolves around the design of a sustainable water concept for built-up areas and its implementation in Nieuwegein.

The research has the following components:

1. Design of a circular water system for an urban city centre

• Sketch(es) of a circular water system for the city centre of Nieuwegein. A sketch is a three-dimensional image, which offers the possibility of exploring the options at different elevation levels. Thus: on the roof (for example blue/green roofs), façade, street level, and in the underground and deep subsurface.
• Technical design, which involves the further refinement of the sketches. These are elaborated in different modules, such as those for the blue/green roofs, greywater system, subsurface water storage, etc.

2. Water technology research

• In this component the most promising options from the design (component 1) are studied in greater depth, and water scenarios are created and elaborated.

3. Risk assessment and water quality

• This component is focused on the water-quality risks and how these risks can be managed under different scenarios. For the participating companies, this component in particular offers a clear added value compared to other water-reuse projects, because they will be able to test the treatment performance of their technology and to develop it further.