In this chapter we move back in time, to when it was not an usance to base our city designs on the natural systems of water and ecology. By the end of the 1980s the dogma of separation of functions, and dividing the city in areas for working, living, leisure and traffic was slowly abandoned and especially the focus on the traffic system, more in particular the car, was leading to uproar. In this timeframe an alternative to apply the principles of nature in urban design was very new and, in the beginning, needed to be conquered on the traditionalists who would pertain using their old-school design standards. In this chapter the development story of Westerpark, and Heilaar-Steenakker is presented. This area in the western outskirts of the city of Breda, in the south of the Netherlands, was one of the first, maybe even the first to use knowledge about the water system, ecological typologies and nature as the basis for urban planning. This article starts with a description in sections two and three of the policy context at national level to illustrate the momentum of change from rationalism towards ecological planning. In section four the policy context in Breda in the early nineties is presented as the context within which the planning of Heilaar-Steenakker (Sect. 8.5) and Westerpark (Sect. 8.6) could be based in a strong sense of the natural processes of ecology and water that formed the landscape in history.
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Climate change and urbanization will increase the frequency and magnitude of urban flooding and water quality problems in many regions of the world. In coastal and delta areas like The Netherlands and the Philippines, where urbanization is often high, there has been an increase in the adoption of sustainable urban drainage systems (SUDS). SUDS are installed around the world with the expectation to reduce urban flooding and reduce the pollution impact on receiving waters. Most cities in Asia are starting to implement SUDS as their strategy to make their cities sustainable and resilient.The combination of SUDS with appropriate wastewater treatment and management systems have the potential to be multifunctional in alleviating flood run-off, improving water quality, alleviating heat stress and as a source for reusing the stormwater and wastewater.Since the earliest SUDS are implemented in Europe decades ago it is advised to use the lessons learnt in this process. International knowledge exchange is promoted in projects as IWASTO where several organisations from the Philippines and The Netherlands join forces on a specific region as the Pateros riverin Manila with the aim to minimise the pollution impact on this receiving water. The first findings of this project related to storm water and wastewater management are presented in this paper. In this stage of the project high level support models that map the challenges in the city (such as flooding and heatstress) arevaluable tools for implementing cost effective sustainable drainage for improving water quality.
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Small urban water bodies, like ponds or canals, are often assumed to cool their surroundings during hot periods, when water bodies remain cooler than air during daytime. However, during the night they may be warmer. Sufficient fetch is required for thermal effects to reach a height of 1–2 m, relevant for humans. In the ‘Really cooling water bodies in cities’ (REALCOOL) project thermal effects of typical Dutch urban water bodies were explored, using ENVI-met 4.1.3. This model version enables users to specify intensity of turbulent mixing and light absorption of the water, offering improved water temperature simulations. Local thermal effects near individual water bodies were assessed as differences in air temperature and Physiological Equivalent Temperature (PET). The simulations suggest that local thermal effects of small water bodies can be considered negligible in design practice. Afternoon air temperatures in surrounding spaces were reduced by typically 0.2 °C and the maximum cooling effect was 0.6 °C. Typical PET reduction was 0.6 °C, with a maximum of 1.9 °C. Night-time warming effects are even smaller. However, the immediate surroundings of small water bodies can become cooler by means of shading from trees, fountains or water mists, and natural ventilation. Such interventions induce favorable changes in daytime PET.
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