The rare spray toad is endemic to the Kihansi Falls habitat in Tanzania, but it may find itself moving home as its presence is reducing much needed power generation at the 180MW Kihansi hydro plant in Iringa.
The energy and minerals minister, Edgar Maokola-Majogo said that about 7m3 of water, equivalent to producing 15MW of electricity has to be sprayed on the toads every second in order for them to survive, and this was not possible in the current power crisis. Rainfall permitting, water flows of 7m3/sec, would only generate 52MW of power at the 180MW plant.
As a result, the minister has ordered a study that may ultimately lead to the relocation of the toad or the creation of a captive breeding programme. Five hundred toads have already been flown to the US where studies will be conducted to determine if the toads can survive in different environmental conditions.
The Kihansi hydro project is located in the Rufiji basin, about 550km southwest of the capital city Dar-es-Salaam. Construction of the hydro project began in 1994 and the scheme comprises a 25m high concrete gravity dam which impounds a small reservoir with a total storage of 1.6M m3, 1M m3 of which is used for daily regulation. The spray toad was discovered in 1996, but by this time it was too late to stop construction. The first of three 60MW Pelton turbines went into commercial operation on 22 December 1999. For more information about the spray toad and the Kihansi hydro plant see IWP&DC December 2000, pp23 and March 2000, pp18-22.