Lake lowering in sulphide-rich areas is currently a major environmental impact for surface water. This study focuses on whether there is a relationship between a gradient of lake lowering and surface water impacts in areas of sulphide-rich sediments, in order to better understand their contribution of heavy metals and sulfuric acid. Also, is it a reasonable method to use the reduced lake area in order to quantify the gradient? The survey was conducted by collecting water samples from reference lakes and lowered lakes from south to north in coastal areas within the county of Västerbotten. Water samples were then analyzed for TOC, pH, conductivity, anions, base cations, alkalinity, acidity, sulfate, Al, Cd, Fe, Mn, Cu, Zn and Pb. These parameters were then compared statistically using regression analysis and t-tests. The results show that no gradient was discernible in response to the reduced lake area. However, significant differences (p < 0,05) between the reference lakes and all the reduced lakes were visible for pH, conductivity, Cd, Cu, Zn and Al. The study shows that there is a correlation between lake lowering and negative impacts on surface water. However, to calculate a gradient from the reduced lake area is deficient as it is limited by the lakes volume reduction, and how the area around the lake has been affected. Further studies on the subject are therefore necessary. / FLISIK (för livskraftiga småvatten i kvarkenregionen)

In 1888, the lake Hjälmaren underwent a process of lowering by almost 2 metres with the aim of gaining 19.000 ha of arable land. This process had a wide array of ecological implications, and in connection with other historical events, it also resulted in spatial and social cracks dividing the city of Örebro laying on Hjälmaren’s west shore. The changing physical aspects of the city have led us to question the relationship of humans and species to the lake, but also to the stream Svartån connecting the lake and the city. Örebro used to be a city of collective practices and shared resources. It had much stronger ties to water as it used to be more present and made the city more centre-oriented. This does not apply today - the city’s development is oriented outwards, its centre lacks in quality non-consumerist spaces and capitalism and individualism are at the forefront. With this explorative design thesis, we propose solutions to activate Hjälmaren and Svartån. Our project widens the offer of common spaces and resources in Örebro, giving its residents more opportunities to interact in the everyday presence of water – just like in the past, but with a more modern spin.

During the first half of the 20th century, lake lowering was a common practice for agricultural drainage in Sweden. Although this phenomenon led to drastic changes in the Swedish landscape, it has been remarkably understudied. Furthermore, previous research on lake lowering, and on the adjacent subject of hydropower, has mostly taken a social constructivist approach. In contrast, the aim of this study was to generate a posthumanist, symmetric account of a lake lowering project, where the non-human actants involved in the network were seen to act. This in order to better understand the driving forces and power relations emerging in a large technical project. The study took the form of an actor-network analysis of the lowering of Lake Tämnaren in the south-east of Sweden. The analysis consists of a chronological account of the project between the years 1923-1967. During the years predating 1950, investigations into both material and social matters were carried out by two engineers who became spokespersons of the many collectives of actants affected by the lake lowering. In the years between 1950-1953 when the project was carried out, the spokespersons’ accounts of reality were challenged, with varying results. After the works had been completed, the question of maintaining a suitable water level in the lake remained controversial and concerned managing the newly built dam. In brief, the conclusions of the study highlight the role of material agency in transporting and changing power between actants in a network. Forms of material agency were for example: the lake flooding, the hardness of soil, or the floodgates of a dam remaining open.