| Great Area Ruaha River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Tanzania |
| Subdivision Type2: | Region |
| Subdivision Name2: | Iringa Region |
| Subdivision Type3: | Region |
| Subdivision Name3: | Dodoma Region |
| Subdivision Type4: | Region |
| Subdivision Name4: | Morogoro Region |
| Length: | 475km (295miles) |
| Source1: | Lukosi River |
| Source1 Location: | Iringa Region |
| Source2: | Yovi River |
| Source2 Location: | Morogoro Region |
| Source3: | Kitete River |
| Source3 Location: | Morogoro Region |
| Source4: | Sanje River |
| Source4 Location: | Iringa Region |
| Source5: | Little Ruaha River |
| Source5 Location: | Iringa Region |
| Mouth: | Rufiji River |
| Mouth Location: | Pwani Region |
| Basin Size: | 83970sqkm |
The Great Ruaha River is a river in south-central Tanzania that flows through the Usangu wetlands and the Ruaha National Park east into the Rufiji River. It traverses and marks the borders between Iringa Region, Dodoma Region and Morogoro Region. The Great Ruaha river has a basin catchment area of 83970sqkm.[1] The population of the basin is mainly sustained by irrigation and water-related livelihoods such as fishing and livestock keeping.
Great Ruaha is about 475km (295miles) long, its tributary basin has a catchment area of 68000km2 and the mean annual discharge is 140m2 per second. The Great Ruaha River supplies 22 percent of the total flow of the Rufiji catchment system. Thirty-eight species of fish have been identified in the Great Ruaha River.
The river's headwaters are in the Kipengere Range In west Njombe Region. From there the Great Ruaha River descends to the Usangu plains, an important region for irrigated agriculture and livestock in Tanzania. The river eventually reaches the Mtera Dam and then flows south to the Kidatu Dam. These two generate about 50 percent of Tanzania's electricity. The river continues southwards and flows across the Selous Game Reserve before reaching the Rufiji River. The major rivers contributing to the Great Ruaha River are Lukosi, Yovi, Kitete, Sanje, Little Ruaha, Kisigo, Mbarali, Kimani, and Chimala whereas the small ones include Umrobo, Mkoji, Lunwa, Mlomboji, Ipatagwa, Mambi, and Mswiswi rivers.
Decreased flows in the Great Ruaha have been recorded since the early 1990s,[2] resulting in complete drying of sections of the river in 1993 and in dry years since (illustration above). This has been attributed to uncontrolled and poor water management, with the large rice irrigation schemes playing a major role.
By 2019, the Great Ruaha experienced no water flow for several months per year. A report published by the World Bank listed the Great Ruaha as an endowment in crisis due to environmental factors.