Mapping climate change - barriers and opportunities for action

Possibilities for adaptation
Traditionally, the immediate response to managing extreme rainfall has been to install larger sewer
pipes and to build retention basins, or to manage surface water locally. In many situations, an
expansion of the existing drainage systems could take place in connection with ongoing renovation
work. Locally, it will be possible to climate-proof against water damming up e.g. in critically sited
basements, or initiatives could be launched to divert the water to where it does least damage. In
practice, an expansion of the sewer system will not always be the most socio-economically
appropriate solution.
Today, some municipalities already partially compensate property owners for the connection charge
(a lump sum) if the owner installs a dry well on his ground to divert rainwater, or another local
rainwater bypass solution. The Danish Nature Agency has analysed the different models that can
provide incentive to reduce the drainage of rainwater into the central sewers. The opportunity for
establishing local infiltration solutions depends on e.g. local soil conditions, and this option is
therefore not present on all locations. Another solution could be to retain and store the rainwater in
basins on the individual property. However, this type of solution may be associated with large costs
for the individual property owner.
Initiatives completed and in progress
Strategic climate change adaptation in Greve Municipality
Due to a greater number of intense flooding events, Greve Municipality has decided the city's surface
and wastewater management system is to be able to cope with 30% more water. The required adaptation
of the system is being carried out at a total of 42 urban districts addressing the most critical areas first.
This climate change adaptation initiative includes both existing and future run-off and drainage
systems, and the entire surface water management system and local watercourses are being included in
the scale-up, which is expected to be completed by 2020. The adaptation initiative is being implemented
using a strategy model that is based on a combined landscape and surroundings model, as well as a
hydraulic model, which calculates how water flows in the drainage systems and in watercourses.
The municipality has also been working on emergency response plans to ensure the municipality will be
able to execute a timely response in the event of extreme rainfall and/or elevated water levels, thus
reducing the extent of damage.
With the enhanced capacity of watercourses and surface water and drainage systems, and the
emergency response planning, the municipality is expected to be able to prevent more negative impacts
from extreme rainfall in future.
Key stakeholders have identified a number of legislative obstacles for financing and incorporating
climate change adaptation efforts in surface water and wastewater planning. A process has therefore
been initiated in order to solve the current problems and to ensure the proper legislative framework
is in place for carrying out the socio-economically best solutions.
The Danish Water Sector Reform Act introduced a price cap which entails that additional expenses
may only be added to charges under special circumstances, e.g. operational expenses for
environmental and service goals. Regulation in the area is however unclear and this has kept many
of the water utility companies from seeking approval of a supplement to the price cap.
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