Copenhagen’s water supply is not prepared for the growing pressure caused by future heatwaves, according to HOFOR, Denmark’s largest water utility. The company warns that lengthy approval procedures are slowing efforts to expand drinking-water capacity across the capital region, where it serves around one million people.
HOFOR, the Greater Copenhagen Utility Company (Hovedstadsområdets Forsyningsselskab), is calling for closer cooperation between the Danish state, municipalities and water suppliers. The warning follows a recent heatwave during which consumption reached record levels and the company struggled to replenish its reservoirs quickly enough.
Record demand strained Copenhagen’s water supply
During the heatwave, HOFOR urged residents across the Copenhagen area to reduce their consumption. The combination of high temperatures and dry weather led to an unusually sharp increase in demand.
“We experienced record-high water consumption in the capital region. It was so much water that we had difficulty keeping up,” HOFOR drinking-water expert Martin Rygaard told Danish public broadcaster DR.
The utility does not expect Copenhagen to run out of drinking water entirely. However, another prolonged heatwave could produce temporary drops in water pressure, particularly for residents living on the upper floors of apartment buildings.
“We will not be left completely without water, but we fear that there may be periods when residents on the upper floors experience a drop in pressure and less water coming out of the tap,” Rygaard said.
HOFOR is renovating parts of its infrastructure to make the distribution system more efficient. The company nevertheless argues that maintenance alone will not provide enough additional capacity to cope with more frequent periods of extreme demand.
Approval procedures can take up to ten years
Expanding the system requires permits for new groundwater wells, waterworks and higher extraction volumes, as well as renewed authorisations for existing facilities. According to HOFOR, obtaining these approvals can take several years and, in some cases, as long as a decade.
“When we need permits, for example to extract more groundwater or renew existing permits, there is a very thorough administrative process that drags on for many years and, in some cases, up to ten years,” Rygaard said.
“We need the process to become simpler and therefore faster.”
The company is not asking authorities to abandon environmental controls. Its concern is that the present timetable makes it difficult to increase capacity before longer and more intense heatwaves place sustained pressure on Greater Copenhagen’s drinking-water system.
Climate change will bring more heatwave days
The pressure is expected to increase as Denmark’s climate becomes warmer. According to the Danish Meteorological Institute (Danmarks Meteorologiske Institut, DMI), the country recorded an average of around two heatwave days per year between 1981 and 2010.
Under a medium-emissions scenario, that figure is projected to rise to approximately five days per year by the end of the century. Less severe warm spells are also expected to become considerably more common, with around 11 additional days per year.
Higher temperatures can cause consumption to rise rapidly as households use more water for gardens, pools and other outdoor activities. This creates short but intense peaks in demand, even if Denmark’s overall annual water resources remain comparatively abundant.
The challenge is therefore not only the availability of groundwater, but also whether utilities can extract, treat, store and distribute enough drinking water at the times when demand is highest.
Denmark’s government promises talks with water utilities
Environment Minister (miljøminister) Maria Reumert Gjerding of the Socialist People’s Party (Socialistisk Folkeparti, SF) said the government was taking the shortage of clean water “very seriously”.
The minister identified two priorities. The first is protecting groundwater by prohibiting pesticides in areas where drinking-water resources are formed. The second is adapting the country’s water system to a future marked by climate change and more frequent drought.
“We cannot avoid the fact that we are facing a future with climate change and more drought, in which clean drinking water will become scarce. Unfortunately, there are no simple solutions,” Gjerding said in a written statement.
“I will enter into dialogue with the water utilities as soon as possible so that we can draw up a plan together and find the best way forward.”
The dispute over approval times highlights a broader problem for Danish climate adaptation: infrastructure intended to operate for decades must be planned before extreme conditions become routine. For Copenhagen, the immediate risk is not a complete loss of supply, but repeated pressure problems and water-saving appeals during summer heatwaves unless capacity can be expanded more quickly.
