The Pangani River (also called Luffu and Jipe Ruvu, especially in older sources, and probably once called Rhaptus) is a major river of northeastern Tanzania
. It has two main sources: the Ruvu, which rises as Lumi at Kilimanjaro, passes through Lake Jipe, and empties into the Nyumba ya Mungu Reservoir - and the from west coming and mainly from Mount Meru
fed Kikuletwa, that also enters into the Nyumba ya Mungu Reservoir. Just after leaving the Reservoir the stream becomes the Pangani that empties into the Indian Ocean at the town of Pangani.
For much of its length the river flows along the regional borders of Kilimanjaro Region and Manyara Region
, before flowing into Tanga
Region, which contains the 68 MW Pangani Power Station and the Pangani Falls Dam. There are several inhabited islands within the river. The river is full of crocodiles; hippopotami are scarcer in its lower parts.The Pangani is 500 kilometres (310 mi) in length.
The mouth is located 52 kilometres (32 mi) south of Tanga.The river is tidal for a distance of 22 miles (35 km) from the entrance.The southern side of the entrance is marked by a perpendicular bluff named Bweni, about 200 feet (61 m) high; there is a village of the same name, Bweni, situated here. The northern side of the entrance is a flat sandy beach that extends from the head of the bay. There are several settlements at the entrance, two on the northern and two on the southern bank. Historically, the town of Pangani, on the river's left bank, had a reputation for fevers.At its estuary, by Pangani town, the river is about 600 feet (180 m) in breadth, and 12–15 feet (3.7–4.6 m) deep.
Several tributaries coming from the Pare Mountains, the Usambara Mountains
and the Wasegiia wilderness join the Pangani in its course. These include the Kibaya, Komkuza, Kwachigulu, Kwamwadyau and Mnyusi.