Ensuring the safety of the converted borrow pit

Several measures should be taken to safeguard the safety of the converted borrow pit. As an open structure, there are three main dangers:

  • People, especially children, and animals may fall into the borrow pit.
  • The water may become contaminated and a source for mosquito breeding.
  • The water from the borrow pit may become unsafe for consumption.

To improve the safety of the borrow pit, a number of measures may be taken in close cooperation with the group of people who manage it:

  • Install fencing to improve safety: The borrow pit may be fenced, either with plant material or by excavating trenches. This reduces the risk of people or animals straying into the storage pond. Tree fencing may also contribute to reduced evaporation from the pond surface. In some cases, the selection of trees may contribute to reducing the incidence of malaria (see next point).
  • Reduce the incidence of vector-borne diseases, in particular malaria: Shallow ponds often become breeding habitats for mosquitos. Vector breeding is considerably less in deeper water. It is important to actively manage and use the pond so that there is sufficient movement of water. Introducing larvae-eating fish species to the ponds can also reduce the risk of mosquito infestation. Tilapia (Oreochromis niloticus) are particularly effective (known to remove more than 90 percent of the larvae) and are a commercially attractive source of protein. The management of vegetation around the borrow pit and the removal of small water-filled depressions can also reduce mosquito breeding. Some trees are known to repel malaria mosquitos, e.g., the olon tree (Zanthoxylum heitzii), native to Central Africa. A number of as-yet experimental methods may control mosquitoes, such as the use of vegetable oil with white colorant. This colorant will reduce evaporation losses (as sunlight is reflected) and the oil will make it more difficult for mosquitos to land on the water.
  • Install hand pumps and sand filters to safeguard water quality: In some areas there is no source of water other than the borrow pit. However, by virtue of being open-surface water bodies, these pits do not provide safe water for direct human consumption. This can be overcome by placing a hand pump and sand filter on the borrow pit, or by household treatment of the water. It is essential to segregate the area where livestock is drinking in order to safeguard the quality of the borrow pit.