New buildings in Amsterdam might be required to store and reuse rainwater

This could make the city more resilient to adverse climate change

All future buildings in Amsterdam, as well as those undergoing major renovations, might be required to collect and reuse rainwater or discharge it with delays. These new rules are set out in a municipal ordinance, which is yet to be agreed upon by the city council later this month. The changes should make the city more climate-proof by preventing flooding of streets and drought during heat waves.

Creating the conditions for a climate-resilient city

Next week, on 14 April, a committee with the City Council of Amsterdam will discuss the ordinance on rainwater, requiring all new buildings to have rainwater retention systems. This might ultimately prevent homes from suffering water damage and streets from becoming flooded.

According to the city authorities, sewers are unable to collect the entire amount of water coming from a downpour. Furthermore, it would be better that all the moisture did not end up in the sewers but rather in the ground, for example. This way, the collected water might be used in periods of heat and drought.

There are various ways to collect water, including infiltration crates, where the liquid is collected in a box and is gradually sunk by the ground. Gardens, including roofs terraces, are also an alternative. Some systems even allow for the rainwater to be used for the toilet or washing machine.

The idea of water storage, as the city website points out, is already included in the plans of many new buildings. Furthermore, the water boards (district authorities, charged with regional water management, including flood defence systems) already had rules for buildings larger than 1,000 m².

Now, this might be extended to the entire capital of the Netherlands and apply for future buildings and those that undergo transformations, such as adding up new floors or changes from office to residential status.

After a committee discussion on the matter next week, the city council shall make a decision on the ordinance on 21 April.