During the past 200 years, human beings have had an impact on almost all the wetlands in Sweden. Some of them were drained to create agricultural land, while forests and marshes were drained to increase forest production. Almost 90 per cent of all the wetlands in the agricultural landscape in southern and central Sweden have disappeared.
The shortage of food during the 19th century was an important and understandable driving force - the people of Sweden were starving!We have, however, been so efficient that many of the birds' resting places and breeding places have been destroyed. As a result, many species of bird that are associated with wetlands, such as ducks and wading birds, have declined in number.
Lowered five times
Lake Hornborga was also affected and, after the level of the water had been lowered five times by the 1930s, the lake almost dried out during the summer. The channels that had been dug quickly led the water out of the lake and the water meadows around the lake were soon being cultivated. In spite of this, the amount of arable land that was recovered was not as great as the companies that were responsible for lowering the water level had hoped. The spring flood was still far too large to enable dry land for cultivation to be created. Instead, the lake started to become overgrown by shore forests, bushes, sedge and reeds - until it was gradually turned into a marsh. One of Northern Europe's most renowned bird lakes was just a memory.
Following a government decision, a unique restoration programme began during the latter part of the 1980s with the aim of recreating a functioning bird lake. Almost 1,200 hectares of reeds were removed by specially-constructed amphibious machines, 700 hectares of forest and bushes were cut down and seven kilometres of channels were dug again. To raise the level of the water by an average of 85 centimetres, a dam and a three kilometre long embankment were built on the western side of the lake. In the autumn of 1992, the water began to be raised and the work was completed in 1995. After it had been raised, the average depth of the water in the lake is 0.9 metres.
The restoration has now been completed and no further increase in the level of the water is planned. Work on maintaining the land in and around the lake is, however, constantly in progress.
Lake Hornborga is part of a living cultural landscape and, without the grazing cows, which help to keep the shore meadows open, a great deal would rapidly be lost.
The knowledge that has been acquired from restoring Lake Hornborga is now being passed on. Even the specially-designed machines are being used elsewhere and large areas of Swedish wetland have been restored with Lake Hornborga as a role model.