Water resources
Sweden is rich in water. Lakes account for 9 % of the total area
of the country. There are almost 100 000 lakes, 90 % of which
have an area of less than 1 square km. The four largest lakes
constitute a quarter of the total lake area.
The average runoff in all rivers amount to nearly 200 cubic
km. This means that only 0.5 % of the theoretically available
resource is extracted for municipal use. Stockholm uses only
3 % of the average outflow from the third largest lake in the
country for supplying the metropolitan area with water. Other
users of water in Sweden, such as industry and farming, withdraw
approximately three times as much water as the municipal
sector.
Apart from the southeastern part of Sweden and the largest
islands and the archipelago islands, water supply constitutes no
major problems due to the abundance of available resources.
However, the quality of raw water varies and thus the level of
treatment needed.
The yearly average precipitation varies from 600 mm in the
southeast to over 1 500 mm in the mountains in the northwest.
An average figure for the southern part of the country, where
most people live, may be set at 700 mm.