the impact of flooding in Lagos, Nigeria.
(Former title: Urban flood control, Lagos, Nigeria)
||To mitigate the impact of
flooding in Lagos, Nigeria; Phase 1
to determine the causes of flooding in Lagos and the implications of
tidal and sea-level changes as well as societal impact on the efficiency
of drainage channels to discharge flood waters; Phase 2 (2000-2001)
objective: to reduce the impact of flooding on settlements through
public information and awareness-raising campaigns.
||Nigerian Institute for Oceanography
and Marine Research, Lagos State Ministry of Environment and Physical
Planning (Department of Drainage);
United Nations Educational, Scientific and Cultural Organization (UNESCO):
UNESCO Abuja- Office, Nigeria, and the Coastal
Regions and Small Islands (CSI) platform.
Dr. Larry Awosika, Nigerian Institute for
Oceanography and Marine Research, P.M.B., 12729 Victoria Island, Lagos,
Tel/Fax: 234 1 2619517
project activities have consisted of a study into the efficiency of the
main drainage channels and public awareness activities.
study was conducted to determine the efficiency of the main drainage
channels in Victoria and Ikoyi Islands, Lagos.
This included surveys of the drainage channels and their
outfalls; analysis of the tide gauge, storm surge and meteorological
data; and the preparation of a report for government in August 2000.
awareness campaign was conducted using a public forum and the media
to inform the public about the results of the study.
report was prepared in August, 2000, entitled ‘Study of main
drainage channels of Victoria and Ikoyi Islands in Lagos, Nigeria
and their response to tidal and sea level changes’.
This showed that flooding of Victoria and Ikoyi Islands
predominantly occurs during the rainy season, May to October.
Flooding is more serious when rains coincide with
astronomical high tides.
Analysis of the eight major drainage channels revealed several
problems: clogging of the drainage channels by domestic waste and
blocking of some channels by buildings; low gradient of the channels
and variable channel width from head to outfall; collapsed drainage
channel walls; reverse gradients in most channels such that when
heavy rains coincide with high tides, tidal waters flow back into
the channels through the outlets causing excessive flooding.
A questionnaire survey of the residents showed that few people were
well prepared to tackle the problems; that the drainage channels
were ineffective because they were either blocked by sand or refuse;
and that refuse containers are inadequate leading to dumping of
refuse in the drainage canals by residents.
The report, which was submitted to the Lagos State
Ministry of Environment and Physical Planning, made several
recommendations, including rerouting, repairing, fencing and
screening of several channels; construction of new channels;
increasing beach height; and a public awareness campaign to
discourage dumping of solid refuse in the drainage channels.
A successful media and public forum was conducted on
6th June, 2000. More
than 200 participants attended, including several government
agencies, print media, radio and television stations.
Short term public
familiarisation/sensitisation activities are being undertaken in
2001 by the Nigerian Institute for Oceanography and Marine Research,
UNESCO Abuja-Office, and Clean-up-Nigeria – a non-governmental
organization, focusing on the proper disposal of refuse and the
regular cleaning of drainage channels. Posters, handbills and
pamphlets have been prepared and distributed. Street discussions
near the drainage channels and discussions on radio and television
have been held.
Long term rehabilitation of drainage channels: this will include the
development of a comprehensive master plan for the rehabilitation of
the drainage system in Victoria and Ikoyi Islands. A project
proposal for external funding will be developed in collaboration
with the Ministry of Environment and Physical Planning of Lagos
State, the Nigerian Institute for Oceanography and Marine Research,
Short term public
familiarisation/sensitisation activities: while awaiting the
preparation and implementation of a comprehensive drainage
rehabilitation plan, certain critical issues will continue to be
targeted, in particular the reduction of garbage disposal in the