From the Wikipedia page 
Kalambo District is one of the four districts of the Rukwa Region of Tanzania, East Africa. The administrative seat is in Matai. The Kalambo River flows through the district and its mouth on Lake Tanganyika is about 15 km south of the town of Kasanga.
Kalambo District Council was officially established on 23 December 2012 after it was split off from the Sumbawanga District Council. Moshi Chang'a was the first District Commissioner, who served until his death in a auto accident in April 2014.