Environment and development
in coastal regions and in small islands
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Project Summary
Reducing the impact of flooding in Lagos, Nigeria

Revision date: 5th October 2001
Title:  Reducing the impact of flooding in Lagos, Nigeria. (Former title: Urban flood control, Lagos, Nigeria)
Goals: To mitigate the impact of flooding in Lagos, Nigeria; Phase 1 (1998-1999) objective: 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.
Location: Lagos, Nigeria
Starting date: July 1998
Partners: 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.
Project leader:

Dr. Larry Awosika, Nigerian Institute for Oceanography and Marine Research, P.M.B., 12729 Victoria Island, Lagos, Nigeria.
Tel/Fax: 234 1 2619517
e-mail: niomr@linkserve.com.ng, larryawosika@yahoo.com


The project activities have consisted of a study into the efficiency of the main drainage channels and public awareness activities. 

  1. A 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.

  2. An awareness campaign was conducted using a public forum and the media to inform the public about the results of the study.

  1. A 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.

  2. 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. 

  3. 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.                       

  4. 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.

Future directions:
  1. 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, and CSI.

  2. 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 drainage channels.


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