Water management is already on the road to adaptation, but more action is needed
Operational security of water management must be ensured under all circumstances. Finland has experienced significant disruptions in water supply and wastewater management due to storms, heavy rains, and droughts in the 21st century, prompting water utilities to enhance their preparedness. This has led to the development of local and regional water management strategies, with municipalities intensifying cooperation in areas such as water supply, emergency water supply, and wastewater treatment. Despite these efforts, many plants still lack a comprehensive climate risk assessment, and contingency plans often fail to incorporate climate change considerations.
Drought affects water availability
In response to climate change, droughts are becoming more frequent and prolonged, particularly in southern and central Finland. This poses significant challenges for water utilities reliant on groundwater, as well as those utilizing surface water and managing sewage. Groundwater availability is decreasing, especially in small bodies or where intake approaches maximum yield. Additionally, groundwater level drops can alter water flow directions and increase bank infiltration, leading to water quality degradation. Surface water facilities are also at risk, as drought can cause oxygen depletion, fish deaths, and internal water body stress. During heatwaves, water consumption rises due to increased household use for irrigation, worsening water supply issues. Furthermore, prolonged droughts increase the risk of sewer network blockages and soil cracking, which can damage water and sewer pipes.
Heavy rains and floods hit the water services
The frequency of heavy rains and floods is escalating in Finland, with predictions indicating a tripling of flood risks by 2100. This rise in precipitation and flooding can significantly enhance groundwater and surface water quality, yet it also poses challenges to wastewater drainage and treatment systems. The influx of nutrients, solids, and contaminants into groundwater, especially in areas with thin soil cover, increases the risk of contaminating water intake wells. Surface water quality is also compromised by increased organic matter, pathogens, and nutrients due to heightened water currents. The deteriorating quality of surface waters necessitates enhanced water treatment at various facilities, including surface water, artificial groundwater, and bank infiltration plants. Sewage disposal systems may face increased strain, leading to overflows and bypasses. Furthermore, dilution or cooling of wastewater can disrupt biological treatment processes.
Temperature rises and storms affect water services directly or indirectly
Climate change introduces higher temperatures and more variable weather, including more frequent extreme events. These changes impact groundwater and surface water quality and the management of water supply. Storms and thunderstorms can introduce uncertainties, such as power outages, affecting water supply. In winter, while groundwater formation increases, the reduction in microbiological activity can lower water quality. The need for de-icing roads in winter can elevate chloride levels in groundwater. Warmer surface waters, reduced oxygen content, and algal blooms pose challenges to surface water plants, bank infiltration, and artificial groundwater facilities. Recreational water use and changes in agricultural practices, such as altered farming schedules and increased agrochemical use, further degrade surface water quality. Increased temperatures also affect drainage, leading to odor nuisances and hydrogen sulfide formation, which can damage sewer networks.
Main adaptation measures
Key adaptation strategies include relocating water intake wells and wastewater pumping stations to safer areas, enhancing water treatment capacities, exploring the yield of small groundwater formations, and ensuring backup water and power solutions. Effective planning, inter-facility cooperation, land use management, and the utilization of information systems and modeling are crucial for adapting to climate change. In 2025, an online tool named Vilso was introduced on the Vesi.fi webpage to assist Finnish water utilities in assessing their adaptation needs to climate change.
Johanna Herttuainen
Senior Coordinator
Finnish Environment Institute
Finland
