PARIS €19.24 (-0.21%)

Copenhagen city - Denmark

Adaptation to climate change : flood protection


Prepare the Danish capital for future climate challenges and reduce its vulnerability to flooding. Copenhagen's wish to increase its resilience to flooding - and its wish to optimise wastewater collection systems and treatment plants to ensure that wastewater is not released into the natural environment - are part of a major initiative launched by the public authorities in the 90s.


The customer's objectives

Copenhagen, a pioneering city in terms of sustainable development and environmental protection, wished to address the increase in flooding due to climate change, convert the former industrial port area into a recreational and swimming area, and build a new residential area there.


Veolia's solution

Aquavista™ Plant manages the wastewater collection system and the three treatment plants in real time based on the weather to avoid saturation. Aquavista™ Plant is a sophisticated tool for real-time modelling and control of flows in the city's wastewater collection systems and the three wastewater treatment plants and is combined with a weather monitoring system developed in partnership with the Danish Meteorological Institute. This smart grid ensures that polluted water is not discharged in the harbour during storms through a smart modular software package.



Aquavista™ Plant has been equipped with a prediction tool since 2011: SURF Flood Forecast (SURFF) which anticipates flooding. It indicates where, when, and how high the water will overflow. It also schedules the operations to be carried out by operators and local authorities, such as switching treatment plants into ‘rain’ mode to increase their water collection capacity 6 to 12 hours before the precipitation arrives. 

90 %

Reduction of the number of wastewater spills in Copenhagen Harbour

93 %

 new works and infrastructure investment costs avoided 


Share of pollution removed from Copenhagen Harbour  



The SURFF early warning system is able to predict flooding 6 to 12 hours before it occurs. It uses algorithms that allow real-time network monitoring (optimisation of valves, pumps, and tanks) and ‘switches’ wastewater treatment plants to rain mode to avoid congestion and overflowing.

The solution allowed existing assets to continue to be used - optimisation of existing wastewater treatment plants and network control systems - significantly limiting investments compared to what would have been required to create new infrastructure on the network.

Customer benefits


SURFF improves the city's resilience to flooding: 90 % of annual overflow situations have been removed and sea pollution from wastewater discharges has decreased by a third. Copenhagen Harbour is currently a popular residential area where water leisure activities attract a lot of people.

SURFF has also reduced greenhouse gas emissions associated with wastewater treatment by 10 to 12 % by optimising energy consumption.



The astute investment in SURFF, a rainwater and wastewater management tool, has reduced the amount of energy required to treat them by 10 to 15 %.

The reduction in flooding-related costs is difficult to calculate. However, taking the example of the severe flooding in Copenhagen in 2011 which cost the city 700 million euros, if an alert system has been installed, the city would have saved 35 million euros.



SURFF is very effective in planning what to do in the event of high rainfall, even before it starts. It has also improved the quality of the seawater in harbour which is a popular bathing area.

Contract scope

Site: city of Copenhagen

Population: 2 931 445

Equipment: SURFF tool

Contract term

Since 1992

Business sector


Intelligent and scalable software solutions via the deployment of a smart grid combined with an anticipation strategy through weather monitoring.


The SURFF flood alert system prepares the city for the challenges of climate change and makes it more resilient.

 • 10 to 15 % reduction in energy used for wastewater treatment in a plant already PLC-controlled. Online measurements show a 10 to 12 % reduction in greenhouse gas emissions.

• A third less pollution related to the discharge of wastewater into the sea around Copenhagen. 


Copenhagen Harbour has become a fashionable residential area, the real estate value of which has increased, that offers leisure and bathing activities that are very popular with locals.

The SURface Flood Forecast (SURFF) tool which predicts flooding also plans the actions to take to protect the population.

SURFF's success is also related to a successful partnership between operators and engineers, the training provided, and the pilot tests run. The challenge was to take the recommendations of all stakeholders into account: public water services, local authorities, university research centres and institutes, and, of course, the city's population.