Purification of water

An important aim of the Kävlingeå River Project, as well of the national drive to recreate wetlands, has been to reduce the amount of nutrients transported by streams and rivers to lakes and sea. The Kävlingeå River Project has, in cooperation with a neighbouring project within the Höje å River, conducted extensive monitoring studies of the ability of ponds and wetlands to reduce nitrogen, phosphorus and suspended particles. These studies have been carried out in three ponds for a period of four to ten years. The results are shown in the diagrams.

Our studies show a yearly nitrogen reduction in ponds ranging from 0,4 to 2,2 tons per hectare and a corresponding reduction of phosphorus of 16 to 47 kg. Nutrient reduction in the studied ponds is likely to be above the average reduction of all the ponds and wetlands within the project, due to a somewhat higher load of nutrients. To achieve the maximum reduction, it is important to ensure that the individual pond or wetland is as large as possible and that the supply of nutrient rich water reaching the pond is as big as possible.

Studies carried out during 2005-2008 in the southwestern part of Skåne have shown that restoring wetlands in areas dominated by peaty soils may involve a risk of nutrient outflow, mainly phosphorus. This leakage is largest while the wetland is new and then gradually declines. It is likely that these wetlands too will function as nutrient sinks in the long run. 

Biodiversity

The Kävlingeå River Project has carried out surveys of birds, benthic fauna and vegetation in several of the ponds and wetlands built within the project. These surveys have shown that plants and animals are quick to arrive and establish themselves at new ponds and wetlands. Within a year or so, the flora and fauna of these newly created environments are as diverse as those of similar naturally occurring wetland environments. Several rare and threatened species have been recorded by the Kävlingeå River Project, such as Garganey, Shoveler and Curlew. Rare plants noted during surveys are Bristle-Leaf Bulrush and Fries' pondweed. Surveys of benthic fauna have yielded rare species of beetles, shield bugs and snails.

Although new wetlands generally accommodate a large number of species, species-richness varies a great deal between ponds. In order to achieve environments for as many species as possible, it is necessary to create a variety of types of ponds and wetlands within a region. In the future, there may also be reason to adapt measures to the preferences of certain organisms in order to benefit specific species. Shallow wetlands supplied by groundwater, for instance, are valuable to many species of amphibians, snails and submersed vegetation.

Recreation and outdoor life

The placement of ponds and wetlands within the Kävlingeå River Project has not primarily been determined by the need for recreational areas/areas for outdoor life. However, nearness to populated areas is considered an advantage when assessing the need for and benefits of building a pond or wetland in a certain place. Measures have been taken to improve access to the wetlands and their surroundings, including footpaths, stiles and hides. 

Bridges, rowing boats, canoes and benches are evidence of the recreational value of these newly created ponds and wetlands. They are popular places for walks during the summer, while in winter many ponds are used for skating.