Lake Ohrid area has been a UNESCO World Natural Heritage Site since 1980. The lakeshore reedbeds and wetlands provide a critical habitat for a high number of wintering water birds, including rare and threatened species. The diversion of the Sateska River in the former Yugoslav Republic of Macedonia into the lake increased its watershed area, and consequently the agricultural run-off and sediment input. Sediment loads have also increased, due to unsustainable forest management and subsequent erosion, causing destruction of wetlands in parts of the lake in both countries.