Glomma is the largest river in Norway located in the eastern parts of Norway. The river basin (41 200 km2) is the most populated river basin in Norway, though the population density is low in a global comparison.
The north-western parts of the Glomma basin consist of high mountain areas (Jotunheimen area with Norways highest peak: Gallhøpiggen (2468 m asl.) with high precipitation and glaciated areas. The eastern part is covered by forest areas, whereas the central and southern parts comprise large agricultural areas.
The large side-branch entering into River Glomma between Lake Mjøsa and Lake Øyeren. is often referred to as the Laagen Watercourse. It contains Norways largest lake, Lake Mjøsa, which has a surface area of 350 km2, and a maximum depth of 450 m. At the entrance of Lake Øyeren, River Glomma forms Northern Europes larges inland delta, The Northern Øyeren Nature Reserve, which is regarded as an extremely important wetland for migratory water fowl (Ramsar Site).
Glomma and Laagen river basin has 47 hydro power stations and 26 regulations and water and diversion schemes. Overall storage is ca. 3 500 mill. m3. Hydropower development has a long historical tradition where ecological considerations has been taken when minimum flow requirements (i.e. environmental flow) has been set by the authorities.
The basin has in addition to hydropower development, clearly been influenced by the human impact. The influence is typical for industrialised countries, and includes land use changes (new farmland, deforestation, flood embankments, housing, industrial development, infrastructure, etc) and pollution.
The pollution situation in the river has improved considerably over the last 25 years. However, there are still many small settlements which do not have efficient effluent treatments.
Fishing, both commercial and leisure fisheries, are considered as important. The regulation and the pollution discharges have created problems for these activities. Large amounts of money have been invested in abating the eutrophication of the lake Mjøsa and Lake Øyeren. This abatement has been successful, but a new pollution problem have arisen, that from environmental toxins entering the food chain, making it risky to consume fish. The many regulations has also affected the fisheries negatively many places.
In STRIVER, Glomma will be utilised in twinning case studies on environmental flow methodologies (twinned with Sesan) and pollution load modelling (twinned with Tungabhadra). The well-established procedures for public participation will also be explored in addition to experiences with IWRM.