Climate change is making our cities more vulnerable to extreme weather events, including storms and floods. Rotterdam, the second-largest city in The Netherlands, is no exception. That’s why the team at Dakakker, an urban rooftop farm in the heart of the city, built a smart roof. This intelligent water storage system is automatically driven by the weather forecast and helps the city in its battle against floods.
The Dakakker is a 1,000 square meter urban rooftop farm in Rotterdam. A green paradise in an industrial city: organic fruits, vegetables, flowers, and herbs are grown, bees are kept and chickens wander around freely. But that’s not all. Part of the roof of the building where the Dakakker is located has been transformed into a smart roof. This part of the roof is equipped with a ‘smart flow’ system and a phone card with a 24/7 connection to the weather forecast. If heavy rainfall is predicted and the roof is full of water, the system responds by making extra water storage capacity available up to 24 hours in advance. The roof will slowly start releasing water, up to 12 hours in advance. This way, the roof is half empty or completely empty when the storm is coming and has plenty of room for new rainwater.
Black versus green versus smart roofs
Traditional black roofs don’t have any water storage capacity, making them the least effective for climate change adaptation. The green roof of the Dakakker however, can collect up to 60 liters of water per square meter. The smart roof even has a double capacity and can hold up to 120 liters per square meter.
The smart roof at the Dakakker is around 120 square meters, which is relatively small. And although not all roofs will be suitable for a smart roof, due to the weight of the extra water, the scaling potential is huge. What if there would be 4,000 square meters or an entire neighborhood equipped with this system? It would highly increase the capacity of cities to deal with extreme rainfall and prevent flooding due to rainwater runoff.