Urban Poverty & Climate Change in Dar es Salaam, Tanzania:

Table 2: Information on significant floods in Dar es Salaam, 1983-2006
Monthly rainfall
No. Year Months Longterm Actual Percentage of
Remarks
mean (mm) (mm) longterm mean
1 1983 May 197.8 405.6 205 The rain was enhanced by El Niño.
Tropical cyclone Albera was
2 1989 December 117.8 175.6 149 largely responsible for the heavy
rain.
There was continuous rainfall for
3 1995 May 197.8 374.2 189 at least two days during the
March–May rain season.
October 69.3 250.8 361 The rain was associated with a
4 1997 November 125.9 152 121 strong El Niño episode.
5 1998
December
January
February
March
117.8
76.3
54.9
138.1
231
107.3
123.7
155.2
April
254.2 319.9 126
6 2002 April 254.2 569.4 224 The rain was enhanced by El Niño.
7 2006
November
December
125.9
117.8
240.9
230.4
191
196
The rain was enhanced by El Niño.
Source: Provided by Tanzania Meteorological Agency (TMA), 2010
196
141
225
112
The rain was associated with
strong El Niño episode.
A recent study by Watkiss et al. (2011) shows that currently 140,000 people in Dar es
Salaam are below the elevation map’s 10 m contour line, and over 30,000 are considered
at risk. Measures to gauge and convey risk to the public in advance of flood events are
thus of critical importance in helping people to prepare for them. The Tanzania
Meteorological Agency undertakes these tasks, providing both near term (24 hour) and
seasonal forecasts and warnings (see Box 1).
Box 1: Flood Early Warning Systems in Dar es Salaam
The Tanzania Meteorological Agency (TMA) issues flood warnings for Dar es Salaam. It
provides warnings and advisories on extreme rainfall and flooding based on daily weather
monitoring. Cloud evolution is monitored through observations and by using satellite
pictures. The evolution and pathway of tropical cyclones along the Western Indian Ocean
are also monitored on a real time basis
Warnings and advisories are disseminated to the public as needed, through various
stakeholders such as the mass media and the disaster management department at the
Prime Minister’s Office. Flood warnings and advisories are given up to a day in advance
(24 hour forecast) or at seasonal timescales (up to two months in advance).
Source: Provided by Tanzania Meteorological Agency (TMA), 2010
It should be stressed, however, that flooding in Dar es Salaam’s unplanned settlements is
also largely a function of inadequately maintained storm drains and poor waste disposal
practices, and not just extreme rainfall. In fact, in the study team observed that some
settlements in Msimbazi Valley tended to flood even in the absence of rainfall in the city
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