Abstract:
Rainwater harvesting (RWH) should be regarded as a continuum of techniques that link in-situ
soil-water conservation at one extreme to conventional irrigation at the other. In-situ RWH, comprises
a group of techniques for preventing runoff and promoting infiltration. Micro-catchment
RWH comprises a group of techniques for collecting overland flow (sheet or rill) from a catchment
area and delivering it to a cropped area in order to supplement the inadequate direct rainfall. The
transfer normally occurs over a relatively short distance entirely within the land-holding of an
individual farmer and the system is therefore sometimes known as an "internal catchment"..
Macro-catchment RWH comprises a group of techniques in which natural runoff is collected from
a relatively large area and transferred over a longer distance. Examples of each of these categories
of RWH exist in parts of Tanzania, but their potential is largely neglected by research and
extension services and they are under-exploited. The purpose of this paper was to assess the extent
to which the different rainwater harvesting systems, are used in Tanzania. The findings show that
there is a widespread practice of rainwater harvesting in Tanzania. Rainwater harvesting with
storage of water for livestock has received government support in the past. However, many storage
reservoirs have been destroyed by siltation. On the other hand rainwater harvesting for crop
production has not received an adequate support from research and extension services. Therefore,
although farmers are practicing rainwater harvesting, they are faced with shortage of appropriate
technologies and knowledge
