Project Overview

The Climate of Lesotho

Lesotho lies within the summer rainfall area of Southern Africa and more than 85% of the annual rainfall occurs in the seven months from October to April. Mean annual rainfall ranges from less than 600mm in the lower Senqu valley to 1000mm along the mountain ranges.

Inter-annual variations in rainfall are significant with prolonged dry or wet periods occuring. At higher altitudes, witer nights are very cold and even in the low-lands, frost occurs on over 80 days of the year. In the mountains areas with elevations exceeding 3000m, frost can occur on over 250 days in the year.

Lesotho’s Water Resources

Water is a resource that Lesotho has in relative abundance. Lesotho’s water resources far exceeds its possible future requirements, even allowing for possible future irrigation projects and for general development and improvement of living standards.

The average total available water in Lesotho is about 150m&;#179/s and current national consumption is not more that 2mm³/s.

Estimates of the natural mean annual run-off at the sites of the main project. (Feasibility study estimates).

Dam River Catchment Area(km²) Mean Annual(hmm³) Run Off(m³)/s
Katse Malibamats’o 1860 656 20.8
Mohale Senqunyane 938 367 11.6
Mashai Senqu 7977 1569 49.7
Tsoelike Senqu 10 375 1891 59.9