Sites - Important Bird and Biodiversity Areas (IBAs)
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Kenya, Nairobi Province
37o 1.00' East 1o 14.00' South
Year of IBA assessment
Site description The Dandora Oxygenation Ponds are situated 20 km due east of Nairobi City centre, just off the Nairobi–Kangundo road but within the city limits. The main sewage treatment works for Nairobi City, they comprise three experimental ponds, eight facultation ponds and 24 maturation ponds, all bounded by embankments. The first phase of eight ponds was commissioned in 1980, followed by the much larger second phase in 1992. The older set has mud banks, with associated growth of aquatic and emergent macrophytes such as species of Cyperus and Typha;the newer ponds have gently sloping concrete banks. Water quality and the microflora and fauna change as water progresses through the ponds. The treatment is entirely natural and considered environmentally friendly. Processed water from the ponds is discharged into the Nairobi river.
Key Biodiversity See Box for key species. Dandora holds internationally important populations of Netta erythrophthalma (maximum 3,200 in 1994) and (in the northern winter, November–February) Anas clypeata. Duck are generally numerous, and there are often large flocks of Dendrocygna viduata and D. bicolor, Anas undulata, A. erythrorhyncha, A. hottentota and (among the Palearctic migrants) A. acuta and A. querquedula. January waterbird counts over the eight years 1994–2001 have recorded up to 65 species and a maximum of 22,450 waterbirds (mean, 11,900), duck usually being the most abundant single group. Over 1,000 Chlidonias leucopterus are frequently present. Other conspicuous waterbirds include ibises, herons, geese and a variety of migrant shorebirds. Migrant Motacilla flava and Anthus cervinus are attracted to the pond edges, and seasonal flocks of bishops and queleas occur in the rank vegetation surrounding the complex. The regionally threatened Casmerodius albus is a sporadic visitor, in small numbers.
Non-bird biodiversity: None known to BirdLife International.