Nechranice dam also seems to be the longest bulk embankment dam in the Central Europe (More than 3km). The part of the reservoir and surrounding area has been declared as a part of the Natura 2000 Network
(Natura 2000 is the largest network of protected areas in the world).
Although I didn't look into the recreational sports activity in the area but found that it has a very diversified population of migration and non-migrational birds. A beautiful region to be sure.