Towards a Baltic Sea Region Strategy in Critical ... - Helsinki.fi

CRITICAL INFRASTRUCTURE PROTECTION IN THE BALTIC SEA REGION
The harsh climatic conditions in Finland have created a special attitude to those
hazards the climate provides for the infrastructure of water supply. Pipelines are
built beneath the level of winter frost, which in south Finland is about 70 cm, and
water wells are well-protected against the low temperature.
The old, crystalline bedrock in Finland is part of the Precambrian Fennoscandian
craton and consists mainly of Archean and Paleoproterozoic rocks (Lehtinen et al.
2005). The majority of the Quaternary overburden observed today was deposited
about 10 000 years ago, during and after the Weichselian glaciation. The contact
between bedrock and overburden is very sharp.
Groundwater recharges in Finland in both Quaternary deposits and bedrock
fractures. In the costal area of south Finland the groundwater level reaches its
maximum in winter or in early spring (Soveri et al. 2000). During the spring and
early summer, the groundwater level decreases to the minimum. The remarkable
and useable groundwater resources are from shallow groundwater aquifers, mainly
from Quaternary permeable sand and gravel formations. About 7% of the land area
in Finland is covered by glaciofluvial deposits (Salonen et al. 2002) (Figure 1).
The significant aquifers in south Finland are located in the three Salpausselkä icemarginal
formations and other sand and gravel formations. The First and the
Second Salpausselkäs run parallel in hundreds of kilometers through the large
extensive area from the east to the Hanko area in the south of Finland. The Third
Salpausselkä, on the hand, has a smaller size and found deposited only in the
western part.
The water table of shallow groundwater is often quite near the surface and
therefore easy to exploit. The depths of the water tables vary from less than a
metre to more than thirty metres, with an average depth of about 2-5 metres.
Groundwater resources and water supply as part of critical
infrastructure
Freshwater is one of the most significant natural resources for life on Earth. Only
the well-advised use and protection of freshwater resources might preserve the
current level of current life and standard of living in Europe. Water resources and a
workable water supply belong to the critical infrastructure in society and need
special protection. The most important freshwater resources are located in
groundwater aquifers. In these formations, the water is well protected, better than
surface water, but even this water is at risk. The potential risks might be natural or
man made. The water supply system by itself is sensitive and vulnerable for
climatic, economic, technological or political risks and needs special protection.
Freshwater provides drinking water and household water to communities and
households and supports irrigation for farm production. Many industry processes
and productions need plenty of water of good quality. Approximately 0.7 million
cubic metres of groundwater per day are abstracted from the aquifers in Finland
(SYKE 2007). Groundwater (including the artificial recharge groundwater) from
glaciofluvial aquifers of sand and gravel formations contribute about 60 % of
public water supply, and the number is expected to increase up to 75 % in 2010
(Figure 2). The public water system serves about 4.7 million inhabitants in
Finland, about 0.5 million inhabitants in rural areas depend on local groundwater
resources and use private wells. The number of water works with more than 50
users, was 1900 in Finland in 2001. The calculation of water consumption per
192 NORDREGIO REPORT 2007:5