Bihar Floods- Why UNO has not yet intervened and asked Nepal to control release of water in Kosi River?

Actually, the Koshi Dam is controlled entirely by India. Although it is in Nepal, according to a treaty, Nepal does not have authority to control that dam. That dam has been used just for the benefit of India, and the sufferings of Nepalese people near that area is intolerable. This year, it was unfortunate that it also hit Indian people, but Nepalese people in that area suffer every year.