Calms dam

For a cleaner Baltic Sea

Törnebybäcken, which drains most of the Kalmarslätten just west of Kalmar, is one of the municipality's most nutrient-laden watercourses. Kalmar Airport contributes with the supply of mainly nitrogen which is used to keep the runways ice-free.

Through a unique collaboration between the Swedish Civil Aviation Administration and Kalmar Municipality, a large part of mainly nitrogen but also phosphorus, which would otherwise be added to the Western Lake (a bay of the Baltic Sea), can be removed in the landscaped wetland park Kalmar Dämme. It is nature's own purification plant, where a whole series of natural processes take place that reduce the nitrogen and phosphorus content.

Kalmar Dam has a total water area of about 18 ha.

Biodiversity is increasing

In Kalmar Dam, both overwater and underwater plants have been planted. This is to get an aquatic plant filter with as large a growing area as possible. This streamlines the purification processes. 

Efficient processes benefit plant and animal life. The plants capture dissolved nitrogen and phosphorus. They also provide protection for many different species of small animals, several of which begin the decomposition process of the organic material before fungi and bacteria take over and complete the process.

The large water area also creates suitable habitat for several different kinds of birds. The ducks find plenty of protein-rich food, necessary for the young's rapid growth.

A rebuild of the outlet was made in 2013 with the intention of raising the level in the Dam and increasing the flow for a better treatment effect. At the same time, an adjustment was made to the design of the outlet to promote the possibility for pike and perch to be able to go up into the dam and spawn and eventually increase the amount of these fish in the Baltic Sea.