there, at over 2000 metres above sea-level, lies an important water reservoir - rugezi marsh. it's in danger of drying out. agricultural and energy industries are destroying the basis of its existence. our reporter, julia henrichmann, met up with environmentalists determined to find a solution. >> the rugezi marsh is a 20-kilometer-long stretch of wetlands in northern rwanda. francis musoke is a leading conservationist in the region. >> this swamp helps first of all to filter the water. that is very key to biodiversity. at the same time the swamp harbors these different birds as you can see. but another aspect is that it feeds two different lakes on the other side, but remember also the swamp feeds into ntaruka hydropower station, so those are very key aspects as to why the swamp has to be protected. >> the wetlands are home to many birds, including the grey crested crane. an endangered species. and the ibis. the areas where the birds nest, raise their young and search for food are under pressure. >> one of the greatest dangers is that people sneak in sometimes because you can