So, at Gladsaxe new sports facilities for the Gymnasium have been built around and over ponds and canals for a new drainage system that holds back flood water so it can be dealt with locally by the system over a more reasonable period. For this project costings have been given to show how the different parties have benefitted financially. A traditional project with an underground storm basin would have cost 102 million DKK. The completed project with surface solutions cost 72 million DKK. The municipality has influenced the project and gained financially by providing advice and expertise that was financed from the project costs. The citizens of Gladsaxe saved 30 million DKK on supply expenses and they gained sports facilities, playgrounds, nature trails and new urban spaces.
At the headquarters of Nordisk a nature park of 31,000 square metres has been built with half laid out across the roof of car parks. Covered with grass and meadow plants, it absorbs rain water rather than having it run off the alternative of hard roofing into drains and provides a pleasant new facility for staff and visitors to the company.
In Middlefart management of water is seen as an opportunity to create a Climate City to turn 450,000 square metres into a greener and healthier neighbourhood.
In Køge there is scheme to establish new green spaces and rain water from roofs will be cleaned and returned for washing clothes and flushing toilets.
In Viborg a large new park is being laid out with lakes that retain water that can be cleaned and returned to the water system. Again there is considerable gain from such careful management of storm water … the utility company gains access to a large space where it can manage and clean the water, the municipality can influence the design from the start and gets a new park and the citizens are protected from flooding caused by a sudden cloud burst and gain a new recreational space.
Not all the schemes are on such a large scale. Helenevej in Frederiksberg is the first climate street in Denmark with a permeable surface that absorbs large amounts of water when there is a cloudburst and at Vilhem Thomsens Allé in Valby, rainwater is handled within the courtyard of the housing scheme creating a recreational space and reducing water bills as retained water is now used rather than metered water for watering the planting. The utility company gains financially because it does not have to construct new pipes to take rainwater away from the area.
If people still need to be convinced about the need for such schemes, the exhibition has stark figures for the financial cost of wasting water. An average Danish family uses 40 litres of water per person each day for flushing toilets and for washing which is roughly the amount of rainwater that could be collected from a roof surface of 40 square metres so if water could be stored until it is needed then the roof on a house, on average 200 square metres, could provide all the water needed for washing clothes and flushing toilets rather than the family using drinking water … with a potential saving for a family of 5,000 DKK a year in water charges.
The Rain is Coming - how climate adaptation can create better cities
Danish Architecture Centre until 6 April 2015