Urban water quality

As a result of climate change, our planet is becoming drier, wetter, lighter and warmer. This is affecting the quality of surface water. The exact consequences differ from one area and location to the next. This knowledge dossier helps water management bodies such as district water boards and municipalities to gain more insight into both the potential effects of climate change and adaptation measures relating to surface water quality and aquatic ecology. It also features an overview of measures to counteract negative effects.

The primary reason for compiling the knowledge dossier on “Urban water quality” within the Climate-proof Cities focus area of the Dutch National Water and Climate Knowledge and Innovation Programme (NKWK-KBS) was to explore the effects of climate change and adaptation measures on urban water quality. The latest insights show that the observed effects on water quality and ecology also apply to lakes, ditches, canals and brooks. In parallel to the NKWK-KBS knowledge dossier, the Foundation for Applied Water Research (STOWA) initiated a similar study. This has resulted in the “Guide to Water Quality Stress Tests” (STOWA, 2023). In addition to urban areas, the method outlined in the guide can also be used for water systems in other areas. For that reason, in mid-2025, the results and products from the STOWA study were integrated into this knowledge dossier and the word “urban” was dropped.

How does climate change affect water quality and aquatic life?

Climate change is affecting the quality of surface water in several ways. The water quality can change as a result of physical or chemical changes that climate change is causing in the water itself. Cases in point are salinisation, which involves an increase in salt concentrations, and the concentrations of oxygen, nutrients and micropollutants in the water. In addition, climate change affects every living thing in the water, such as fish, aquatic plants, algae and mosquitoes.

How is climate change affecting the functional water quality?

Changes in the quality of surface water caused by climate change will have consequences for the various functional uses of surface water, i.e. the functional water quality. For example, blue-green algae are increasing as a result of climate change, which may impact the possibilities for angling and swimming in surface water.

How vulnerable is a water system to climate change?

In your capacity as a water management body, would you like more insight into a particular water system’s vulnerability to climate change? Various tools in this knowledge dossier can help you on your way.

Gain insight into the vulnerability of a water system

What makes a water system vulnerable to climate change?

One water system is more vulnerable to the effects of climate change than another. How come? Each system has different characteristics, which are affected by different factors: the system’s situation in the landscape, its genesis, its supply and discharge regime, pollution from various substances, and of course the dimensions of the water itself. That is why vulnerabilities must be determined separately for each individual system.

What effects do adaptation measures have on water quality?

Adaptation measures help us to climate-proof the environment, so we are in a better position to deal with increasing drought, precipitation and heat. However, some adaptation measures may have a negative impact on water quality. To prevent such a negative impact, it is important to know what effects may occur.

How can negative effects on water quality be counteracted?

Counteracting the negative effects of climate change or of adaptation measures on water quality may require taking measures. This knowledge dossier features an overview of tools that will help you to determine which measures are needed.

Go to the tools to find water quality measures

How do you design an area with an eye for water quality and climate change?

Would you like practical guidelines for factoring in water quality and climate change in area developments? The Guide to Assessing Water Priorities gives you practical advice.

Research constitutes the basis for this knowledge dossier

The background information to this knowledge dossier is found in the following research reports (in Dutch):

The Guide to Water Quality Stress Tests has been developed by a consortium of Ambient BV and Witteveen+Bos consulting engineers, with input from Deltares, Haskoning, Arcadis and TAUW experts, under the auspices of the Foundation for Applied Water Research (STOWA). The guide supplements products developed under the National Water and Climate Knowledge and Innovation Programme (NKWK). The results of the study have also been processed into a calculation tool (meta model) for compiling a stress test based on climate figures and a roadmap for defining potential water quality measures.

The National Water and Climate Knowledge and Innovation Programme (NKWK) studies of 2022 and 2023 were conducted by a consortium of the National Institute for Public Health and the Environment (RIVM), Deltares, Arcadis, TAUW and the Climate Adaptation Services foundation. The results of the report were processed into an interactive knowledge document (pdf, 13 MB) and a tool indicating limiting values for the functional water quality of urban water. The National Water and Climate Knowledge and Innovation Programme (NKWK) study of 2021 was conducted by the National Institute for Public Health and the Environment (RIVM), Deltares, Arcadis and Wageningen Environmental Research (WENR).

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Go directly to the knowledge document

Would you like to go straight to information on the impact of climate change and adaptation measures on water quality? Then view the knowledge document. This interactive guide shows how climate change and adaptation measures can affect the sensitivity of a water system.