Tanzania: Working towards better ecosystems in Pangani river basin

20 March 2008 | News story

A new project in Tanzania's Pangani river basin aims to improve water flows for the benefit of all its users.

Extending from the mountainous southern reaches of Kenya down to the lowlands of the Tanzanian coast, the Pangani river basin is reeling from over-use and over-allocation.

The basin is stressed, with many latent and emerging conflicts among its users, and current supplies are unable to meet demand. Realising that the national situation generally was headed for disaster, the Tanzanian government elaborated a new water policy in 2002 which sought to redistribute the waters of the Pangani basin in a more equitable manner. Traditionally users in the northern highlands have had abundant water supplies, while consumers in the drier southern coastal areas have suffered more deprivation.

Several factors have contributed to the current state of the Pangani basin, including increased demand for water, changing climatic conditions, competing uses, over-abstraction and watershed degradation.

The new policy contends that basic human needs will take priority in water allocation, followed by environmental issues after the government acknowledged the importance of healthy ecosystems for sustainable development.

But a crucial question remains: how much water does the environment need to stay healthy?

In a bid to answer this, IUCN has been giving technical support to a project of the Tanzanian water ministry conducted through its Pangani Basin Water Office in Moshi, at the foot of Mount Kilimanjaro. The Integrated Flow Management (IFM) project seeks to determine how much water is needed for the basin’s ecosystems to maintain themselves and their functions. Detailed studies of the hydrology, river health, estuary health and socio-economics of the basin were carried out as initial steps of the IFM, leading to the current phase in which scenarios for six different water allocation options have been devised by a multi-disciplinary team of Tanzanian experts.

Guided by a team of experts from South Africa who have pioneered the field, the Tanzanians – drawn from the government, academia, and NGOs – developed water allocation scenarios taking into account the social, economic and environmental impacts. These include agricultural expansion as a priority; hydropower production as a priority; keeping the status quo; impact on other sectors by boosting the condition of ecosystems; implementing the national water policy with a focus on agriculture; implementing the water policy with a focus on hydropower. Impacts on livelihoods, utilities and the economy were also assessed.

Both the Tanzanian government and the South African consultants are very excited by the prospects of this project, hoping it can be replicated throughout the country. The consultants point out that much of the pioneering work on assessment flows is being carried out in Africa with the focus on sustainable livelihoods.

Notable results have already been produced. For instance, poverty reduction measures traditionally call for increasing agricultural output. But in Pangani, water allocation currently favours the agricultural sector so there is not much more room for growth here and it’s an option that could be ruled out. Advocates of boosting hydropower are normally at odds with conservationists. However the downstream site of the Pangani hydropower station, which is a more degraded environment, means that by increasing water for hydropower output, the environment would also benefit, keeping both sides happy.

Long term, water allocation of the Pangani river basin should also look at small scale investment and water storage for the dry season.

These current options provide a starting point for discussion, and it’s likely that the optimum scenario will be drawn from a combination of these different strategies, with a view to raising awareness of the benefits of the new system among stakeholders by June 2008.


This image shows the courtship behavior of Indian Bull frogs (Holobatrachus tigerinus). During the monsoon, the breeding males become bright yellow in color, while females remain dull. The prominent blue vocal sacs of male produce strong nasal mating call.