The highland zone covers the south-eastern part of the basin including the central Mbeya plain and Poroto highlands. It covers the districts of Mbeya DC, Mbozi DC, Mbeya City, and small parts of Chunya DC and Momba DC. The area is traversed by several hills punctuated by fertile valleys with altitude ranging from 600 to 2,400 m above sea level and mean annual rainfall ranging from 700 to 2,300 mm. It is characterized by generally good fertile soils, reliable and plentiful rainfall, moderate temperatures, and high agricultural potential. There are three predominant soil types of moderate to high fertility including deep volcanic soils, clay soils with a good mixture of sand and alluvial loam, and silt soil within the valleys. The prevalent vegetation types include a mixture of acacia bushland and grassland of brachystegia woodlands most of which has been widely cleared to create land for the expanding agricultural activities. Major crops grown in this zone include coffee, maize, beans, tea, and banana, and to a smaller extent Irish and sweet potatoes, paddy, pyrethrum, and cocoa. Livestock keeping is widely practiced too.
The zone is home to Mbeya City, the largest urban area in Lake Rukwa basin with population of about 385,279 (2012 National Census). Other smaller urban areas in the zone include Mbalizi, Mlowo, Vwawa, and Tunduma. These urban areas are characterized by better socioeconomic infrastructure (e.g. roads, hospitals, markets, communication, etc) and are thus attractive to businesses, skilled labor, and private investors. All these factors combined are responsible for the high population and concentration of socioeconomic activities in the zone compared to other zones in the basin.
Agriculture is the most important socioeconomic activity employing about 70% of the population in the zone. Other major activities include business, formal employment, and livestock keeping. There is a high concentration of irrigation activities in the Highland zone compared to other zones in the basin. All the major industries in the basin are located in the Highland zone, in close proximity to Mbeya City for operational, logistical, and commercial reasons. There are also some limited mining activities taking place in the zone most notably Limestone and Marble.
The heavy concentration of socioeconomic activities has serious implications on the management and use of water resources in the zone. The area experiences significant water shortages especially during the dry season resulting in disruption in different socioeconomic activities. Competition for water use between different sectors and within individual sectors during the dry season often results in escalation of water use conflicts. Most of the observed water shortages can be attributed to inadequate water storage and distribution infrastructure. The area receives sufficient rainfall and if adequate storage infrastructure were available to store some of the run-off during the rainy season for use during the dry season, then most of the observed water shortages would not be occurring.
The other challenge the zone is facing relates to environmental degradation and pollution of water sources due to various human activities. Poor farming practices, deforestation, inadequate sanitation facilities, and pollution from untreated industrial and mining effluent pose a bigger threat to water resources than the current water demand and use levels.