Coventry University DOCTOR of PHILOSOPHY Investigating The
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Coventry University DOCTOR OF PHILOSOPHY Investigating the potential of using simple SuDS in informal settlements in Lagos, Nigeria to transition to a sustainable surface water management system Mezue, Margaret Award date: 2019 Awarding institution: Coventry University Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of this thesis for personal non-commercial research or study • This thesis cannot be reproduced or quoted extensively from without first obtaining permission from the copyright holder(s) • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 11. Oct. 2021 Investigating the potential of using simple SuDS in informal settlements in Lagos, Nigeria to transition to a sustainable surface water management system Margaret Mezue September 2017 A thesis submitted in partial fulfillment of the University’s requirements for the Degree of Doctor of Philosophy i | P a g e Some materials have been removed from this thesis due to Third Party Copyright. Pages where material has been removed are clearly marked in the electronic version. The unabridged version of the thesis can be viewed at the Lanchester Library, Coventry University. ii | P a g e Some materials have been removed from this thesis due to Third Party Copyright. Pages where material has been removed are clearly marked in the electronic version. The unabridged version of the thesis can be viewed at the Lanchester Library, Coventry University. iii | P a g e Declaration I declare that this project is the result of my own work and all the written work and survey are my own, except where stated and referenced otherwise. This thesis has not been accepted or submitted for any comparable award elsewhere. I have given consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organisations. Signed: Margaret Mezue Coventry University, September 2017 iv | P a g e ABSTRACT Rapid urbanisation, coupled with climate change, highlights the underperformance and failure of current conventional water management systems. Flooding during the rainy season has become a yearly phenomenon for most countries across Africa, with the poor, living in slums or informal settlements being impacted the most. In order to better manage this problem, this research investigated the potential of adopting a sustainable alternative: sustainable surface water management (SSWM) systems. A transition framework was developed to deliver SSWM focused on informal settlements using sustainable drainage systems (SuDS) as the major driver. SSWM systems reduce runoff by treating stormwater as close as possible to its source, preferably on site. Presently, there appears to be a paradigm shift towards more SSWM practice in developed countries with the growing adoption of SuDS to replace or work in conjunction with, existing conventional drainage methods. However, less-developed countries (LDCs) such as those in West Africa still rely solely on conventional drainage methods. Lagos, Nigeria was chosen as the study site, as it suffers regular flooding, is surrounded by informal settlements, and the existing drainage infrastructure is generally not fit for purpose. A mixed research method was adopted to collect data for this study. This entailed the administration of questionnaires, interviews and focus group meetings with relevant stakeholders, including residents, community leaders and government officials. Data was collected in 2 visits between April and August 2015 across 9 settlements in Lagos. The first visit comprised the administration of 150 questionnaires across the visited sites, and 76 of these were retrieved. Focus group meetings were also conducted to familiarise the respondents with SuDS. During the second visit, 154 questionnaires were retrieved of the 200 distributed, and interviews were carried out with 15 participants, including residents (formal and informal alike), community leaders and government officials. The result from this study indicated that the informal settlers experienced more flooding episodes and also more severe incidences than those living in formal areas. Compared to the formal settlers, negative impacts were much worse and flood waters remained for longer periods in the informal settlements. Further findings showed that the government placed little or no emphasis on addressing these flooding issues in the informal areas. Additionally, the realisation that conventional systems are failing was highlighted in the results, as respondents indicated that blocked gutters were a major cause of flooding. It was also found that the informal residents were interested in the concept of SSWM and its implementation using SuDS in order to address the ongoing flooding issues. These findings clearly demonstrate a need to address these issues, hence, for the first time a framework has been developed focused on informal settlements to set out a process whereby SSWM could be achieved. This framework aims to guide stakeholders in the water management sector to achieve SSWM through the adoption of SuDS. The transition framework has been designed by adapting and building upon 4 existing water v | P a g e management frameworks, but tailored to suit developing countries. It has been evaluated by field experts across four countries: Nigeria, Gambia, Uganda and the UK. The evaluation process indicates that the framework is fit for purpose and can deliver SSWM. The design consisted of 4 iterative phases: Phase 1, knowledge/change; Phase 2, strategy; Phase 3, tactics; and Phase 4, implementation and maintenance. It identifies the implementation of SuDS as an essential tool to ensure SSWM. This study has collected data on flooding issues and events amongst selected informal settlements that have not been previously investigated or recorded. This data was a pre- requisite for the development of a novel framework to guide the transitioning to SSWM by all stakeholders. The use of simple yet effective methods have been investigated and evaluated to sustainably manage runoff in this study. Furthermore, the framework delivers a sense of responsibility to residents as well as officials to effect positive and sustainable change to their water management systems, not just in Nigeria but in other LDCs. Keywords: Conventional drainage, Flooding, Informal settlements, Transition framework, Sustainable Drainage Systems (SuDS), Sustainable Surface Water Management (SSWM), Stakeholders, Urbanisation. vi | P a g e Dedication This work is dedicated to God Almighty in whom I live, move and have my being, without whose grace this would be impossible. I also dedicate this work to my parents. Dad, Late Lambert Levi Brown Ogolo, many years ago you planted a seed, and God willing it has come to fruition. I hope I have been able to live up to your expectations and have made you proud. Mum, Mrs. Valentina Veronica Anne Ogolo, words are not enough to say thank you for all your sacrifices and support, moral and otherwise. Finally, my kids Kamsiyochukwu Mezue and Munachiso Mezue, this is dedicated to both of you, who have been the reason for it all. You have both been my greatest motivators to see this to a finish. vii | P a g e Acknowledgement A very big thank you to my supervisory team, my director of studies Professor Susanne Charlesworth, for your immense support, patience and encouragement. You have been a support pillar without which this would not have been possible. Dr. Frank Warwick, for your time, support and encouragement I can never thank you enough, Dr. Marion Macllelan and Dr. James Bennett your time, guidance and encouragement are extremely appreciated. My family, you are the giants upon whose shoulders I stand, words can never be enough to say how grateful I am. Special mention to my husband, Nnaemeka Mezue, thank you for everything, I am grateful for the sacrifices you have made and still are making, thank you for believing in me. My sister, my best friend Ayawarifa Mekoma, my angel sent from God, we both know words cannot begin to describe how grateful I am for all you do. My brother Gilbert Ogolo, you have been my rock, for your constant support, sacrifices and proving over and over you have my back; you as well know words can never be enough to say thank you. I am eternally grateful to you all. My friends, without whose support and guidance this would have been impossible. Elizabeth Olowu, Dr. Jennifer Okolai, Rhume Eburu, Mr. Franklin Onwa, Dr. Ernest Nnadi, the Oyedes, Ogadinma Mba, Dornu Longe. I appreciate every single one of you and thank you all for standing in the gap for me. I would also like to acknowledge the staff of the Ministry of Environment Lagos State and Dr. Olaniyi Ayodeji, for all your support during my field study to Lagos Nigeria, I appreciate the time you all took out of your busy schedules to assist me. viii | P a g e Table of Contents CHAPTER 1: INTRODUCTION ................................................................................