Publication: Return on Investment in Green Urban Development: Amelioration of Flood Risk in the Msimbazi River Catchment, Dar Es Salaam, Tanazania
Date
2017-04-01
ISSN
Published
2017-04-01
Author(s)
Turpie, Jane
Kroeger, Timm
De Risi, Raffaele
de Paola, Francesco
Letley, Gwyneth
Forsythe, Katherine
Day, Liz
Abstract
Rapid urbanisation is taking place at an
unprecedented rate throughout the world, with the rate of
growth often outpacing urban planning and the capacity of
city managers. As a result, existing natural areas within
cities,which provide a range of benefits to urban
dwellersare becoming smaller and degraded, and problems such
as flooding, air pollution and water pollution are becoming
worse in many places. African cities often lackthe resources
to deal with these problems. However, anumber of studies
have suggested that investing in the maintenance or
restoration of natural infrastructurein many cases may not
only address given problems at comparable or lower cost than
conventional engineering projects, but also generate
multiple additional benefits that ultimately translate into
cost savings and increased human wellbeing. Meanwhile, great
strides have been made in the design of sustainable
mechanisms to deal with urban environmental issues,
stormwater flows and the attendant pollution problems, and
management and planning of cities is increasingly taking a
holistic approach that includes the use and conservation of
semi-natural and natural areas within cities as part of a
green urban development strategy. One of the challenges of
green urban development will be to findthe right balance
between ecological infrastructure(natural systems), “green”
(= environmentally friendly)built infrastructure, and
conventional (“grey”) built infrastructure. Dar es Salaam,
located on Africa’s Indian Ocean Coast,faces a multitude of
environmental problems. Prominent among them is the problem
of flooding in and around the city centre, which frequently
brings the city to a standstill, as well as causing
infrastructural damage. Many factors have contributed to
this problem, including unplanned informal settlements in
the upper catchment and floodplain areas, a lack of drainage
and a lack of solid waste management. The impacts of
flooding are also exacerbated by high levels of pollution in
the rivers, which increases the risks associated with
flooding. In consultations for this study, stakeholders in
Dar esSalaam identified the Msimbazi River as being amongthe
most degraded ecosystems in the city and also the source of
the most serious flooding problems. The aim of the study was
to explore the potential costs and benefits of undertaking a
green urban development approach, including
catchment-to-coast restoration measures, to ameliorate flood
risk in the Msimbazi Rivercatchment.
Citation
“Turpie, Jane; Kroeger, Timm; De Risi, Raffaele; de Paola, Francesco; Letley, Gwyneth; Forsythe, Katherine; Day, Liz. 2017. Return on Investment in Green Urban Development: Amelioration of Flood Risk in the Msimbazi River Catchment, Dar Es Salaam, Tanazania. Promoting Green Urban Development in Africa;. © World Bank, Washington, DC. http://hdl.handle.net/10986/26702 License: CC BY 3.0 IGO.”