Climate change is showing its face in the Pangani basin. The Pangani River Basin covers an area of about
56,300 km2, with 5% of this in Kenya and 95% spanning the Arusha, Kilimanjaro and Tanga regions of
Tanzania. The Pangani River drains Mount Kilimanjaro and Mount Meru as well as the Usambara
and Pare Mountain ranges which are famous for their endemic biodiversity. The Pangani River passes
through the arid Maasai Steppe and feeds the cities of Arusha and Moshi before it reaches the Indian Ocean
where it supplies freshwater to the coastal town of Pangani and the mangrove forest at the
delta.

Flows in the basin have been reduced from several hundreds to less than 40 cubic metres per second. And that remaining water is seriously overallocated. The main sources of demand are inefficient furrow-based irrigation systems. The consequences are felt throughout the basin, from the irrigation fields in the centre of the basin and the electricity producers further downstream, to the coastal communities that see saltwater move inland and fish stocks decline.The shortage of water are leading to tensions between water users from the various sectors. Large and smaller conflicts are on the rise. The pressure is increasing as the awareness that in future even less water may be available is growing. Especially for the urban centres of Moshi, Arusha and Pangani, the need to meet the needs of the population - expected to rise to 163,000 m3 per day in 2025 - is becoming a worry.

Cloud forests are of great importance in the hydrological functioning of watersheds in subhumid East Africa. However, the montane forests of Mt. Kilimanjaro are heavily threatened by global change impacts. Based on an evaluation of over 1500 vegetation plots and interpretation of satellite imagery from 1976 and 2000, land-cover changes on Kilimanjaro were evaluated and their impact on the water balance estimated. While the vanishing glaciers of Kilimanjaro attract broad interest, the associated increase of frequency and intensity of fires on the slopes of Kilimanjaro is less conspicuous but ecologically far more significant. These climate change-induced fires have lead to changes in species composition and structure of the forests and to a downward shift of the upper forest line by several hundred metres. During the last 70 years, Kilimanjaro has lost nearly one-third of its forest cover, in the upper areas caused by fire, on the lower forest border mainly caused by clearing. The loss of 150 km2 of cloud forest - the most effective source in the upper montane and subalpine fog interception zone - caused by fire during the last three decades means a considerable reduction in water yield.