Visit to potential demo-sites in Gudbrandsdalen Valley, Norway
Mari Olsen and Turid Wulff Knutsen of the Oppland County Authority (OFK) met with NGI’s Anders Solheim in Lillehammer on Monday September 3rd to discuss potential nature-based solutions, which OFK plans to propose and implement in PHUSICOS. Following the meeting, Jon Sylte from Gausdal Municipality joined us as we toured the area to get a closer look at the potential sites.
One possible nature-based solution is to replace an old (1995) flood barrier with a new barrier placed 100-250 m away from the tributary river Gausa. This will provide space for the river during periods of flooding and improve the capacity for upstream flood levels, as well as contribute positively to the flood plain ecosystem. The picture above shows Lake Finntjern, with the original dam. The idea is to raise this by 0,5-1,0m.
One of the bogs proposed for retention basins is behind the trees in the right-hand part of the photo, The road will be raised by roughly 1-2m relative to its lowest point.
Another nature-based solution is to utilise bogs and a small lake located upstream as retention basins to delay flooding to two small rivers which frequently cause problems, such as erosion, in the populated areas downstream during floods. The measures may be carried out by establishing small dams, with suitable drainage to ensure normal discharge in the rivers throughout the year. The measure in the bogs can be carried out by raising two short stretches of already existing forestry roads.