Water supply and sewerage – Adaptation

Flood directive emphasises the natural treatment of stormwaters

In terms of water supply and sewerage, a municipality's responsibilities are related to the development of water supply and sewerage and drawing up an emergency plan. In addition, a municipal public health official controls the quality of drinking water, while the permit and monitoring tasks are the responsibility of the environmental protection authorities. EU's flood directive expands the responsibility of the municipalities with respect to stormwaters

• By moving the stormwater infrastructure from the waterworks to the control of the municipalities and
• By emphasising the 'natural' treatment of stormwaters instead of pipings and flood control.

Financial damage caused by floods easily become extensive. In addition, they have a large-scale social impact. Floods caused by downpours pose a growing challenge.

Changes in precipitation have an impact on groundwater reserves

With respect to water supply and sewerage, key impacts of climate change include changes in the seasonal discharge and downpour situations. In connection with the rise in temperatures, changes in the precipitation change the division of discharges and discharge peaks. Discharges remain higher all through the winter and the discharge peak during the spring is evened out as there is less meltwater.

In some places, drought may cause problems, and lack of rain during the summer may be a problem for small intake works. Drought may also cause problems to the quality of the groundwater.

Stormwaters strain the wastewater treatment plants

Built areas which have an extensive surface impervious to water are most vulnerable to downpours. The problem is the greatest in areas where the stormwaters are able to burden the wastewater treatment plants due to a combined sewer system. In the case of spillovers, bodies of water are released with impurities and nutrients. In addition, rain water washes and carries impurities with it.

On the coast, seawater floods can hinder the operation of water supply and sewerage and even affect the quality of groundwater in some locations. Moreover, some of the wastewater treatment plants in Finland are located in flood risk areas.

Reference [1]