Dams Safety and Society

175 Pages·2022·16.958 MB·English

by  Ljiljana Spasić-Gril

Dams Safety and Society
This book addresses current international practices applied for dam safety assessments
by looking at a portfolio of dam safety projects in various developing countries (Armenia,
Georgia, Tajikistan, Mauritius, Madagascar, Sri Lanka, Myanmar and V ietnam) spread
across three continents (Europe, Africa and Asia). Safety assessment involved the review
of 134 existing dams and comparison with the best international practices in developed
countries. A large part of dam safety assessment involves understanding of dam hazards,
standards applied in the design and maintenance, as well as expectation and social cir-
cumstances under which the dams have been designed and constructed in a particular
country. For example, standards for design floods, ground investigation, selection of de-
sign soil parameters and design earthquakes etc. used are often either non-existent or in-
adequate, which could lead to an unsafe design. If there are no standards to be applied in
dam design and construction, consultants are often under pressure from clients to come
up with minimalistic investigation and designs which, a few years after dam construction,
show signs of deficiencies. Very often countries have no regulations and standards for
requirements that should cover the maintenance and operation of dams.
The book also describes the Portfolio Risk Assessment of Dams, which can be
used as a tool by clients and the funding agencies to identify priority assessment and
rehabilitation projects that consider societal and economic losses. It also demonstrates
how the implementation of Emergency Preparedness Planning could significantly re-
duce the number of people at risk.
The book aims to help clients, consultants and funding agencies which are en-
gaged in dam safety assessment projects in developing countries to focus on issues that
are based on past lessons learnt.

Dams Safety and Society
Ljiljana Spasic-Gril
Cover image: Ljiljana Spasic-Gril
First published 2023
by CRC Press/Balkema
Schipholweg 107C, 2316 XC Leiden, The Netherlands
e-mail: [email protected]
www.routledge.com – www.taylorandfrancis.com
CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business
© 2023 Ljiljana Spasic-Gril
The right of Ljiljana Spasic-Gril to be identified as author of this
work has been asserted in accordance with sections 77 and 78 of the
Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this book may be reprinted or
reproduced or utilised in any form or by any electronic, mechanical,
or other means, now known or hereafter invented, including
photocopying and recording, or in any information storage or retrieval
system, without permission in writing from the publishers.
Although all care is taken to ensure integrity and the quality of this
publication and the information herein, no responsibility is assumed
by the publishers nor the author for any damage to the property or
persons as a result of operation or use of this publication and/or the
information contained herein.
Library of Congress Cataloging-in-Publication Data
A catalog record has been requested for this book
ISBN: 978-0-367-33534-2 (hbk)
ISBN: 978-1-032-30510-3 (pbk)
ISBN: 978-0-429-32045-3 (ebk)
DOI: 10.1201/9780429320453
Typeset in Times New Roman
by codeMantra
For our dearest Mila

Contents
Preface xi
Acknowledgements xv
List of abbreviations xvii
About the author xix
1 Introduction 1
1.1 Background on dam safety 1
1.2 This book 3
Note 4
2 Main aspects in dam safety assessment and principles and
concepts applied 5
2.1 Data collection and assimilation 5
2.2 Approach to dam safety evaluation 5
2.2.1 Information on dam design life 5
2.2.2 Safety criteria for assessment of the design life of dams 6
2.2.3 Dam risk classification 6
2.2.4 Potential failure modes 7
2.3 Site inspection 9
2.4 Safety evaluation of design, construction, and operation 12
2.4.1 Hydrology, flood routing, design, and safety check floods 12
2.4.2 Dam breach assessment 15
2.4.3 Sedimentation 16
2.4.4 Geological, geotechnical, geotechnical, and
geophysical conditions 16
2.4.5 Seismicity 17
2.4.6 Reservoir basin 20
2.4.7 Dam body 21
2.4.8 Overflow spillway 24
2.4.9 Outlet works 26
2.4.10 Review of instrumentation, operation and maintenance
and emergency preparedness plans 27
Notes 30
viii Contents
3 Case studies: Eurasia/Western Asia – Armenia 31
3.1 About the country 31
3.2 About the dams 32
3.3 Dam safety projects II 33
3.3.1 Scope of the project 33
3.3.2 Field investigations 34
3.3.3 Studies 34
3.3.4 Typical deficiencies and structural rehabilitation works
proposed for existing dams in operation 37
3.3.5 Specific dam safety issues related to the Marmarik dam 38
3.3.6 Portfolio risk assessment 42
3.3.7 Dam safety plans 43
3.4 Conclusions and challenges 43
Notes 44
4 Case studies: Eurasia/Western Asia – Georgia 45
4.1 About the country 45
4.2 About the dams 46
4.3 Irrigation and drainage community development project - dam
safety action plan 46
4.3.1 Scope of the project 46
4.3.2 Field investigations 47
4.3.3 Studies 48
4.3.4 Typical deficiencies and rehabilitation works proposed
for four dams 51
4.3.5 Safety aspects of the Rioni diversion weir 51
4.3.6 Risk assessment 55
4.3.7 Dam safety plans 56
4.4 Conclusions and challenges 56
Notes 57
5 Case study: Central Asia – Tajikistan 59
5.1 About the country 59
5.2 About the dams 59
5.3 Nurek dam 61
5.3.1 Background 61
5.3.2 Main project features 62
5.3.3 Dam safety and reservoir management project and
Nurek HPP rehabilitation project 66
5.4 Usoy dam and Lake Sarez 69
5.4.1 Introduction 69
5.4.2 Risks 70
5.4.3 Lake Sarez risk mitigation project 70
5.5 Conclusions and challenges 73
Notes 74
Content s ix
6 Case study: South Asia – Sri Lanka 75
6.1 About the country 75
6.2 About the dams 76
6.3 Dam safety and reservoir conservation project 78
6.3.1 Project background 78
6.3.2 Profile of dams 79
6.3.3 Inspections and condition of dams 80
6.3.4 Operation and maintenance (O&M) 82
6.3.5 Emergency preparedness 82
6.3.6 Reservoir conservation 83
6.3.7 Dam safety legislation 84
6.3.8 Portfolio risk assessment 84
6.4 Conclusions and challenges 85
Notes 85
7 Case studies: South East Asia – Myanmar 87
7.1 About the country 87
7.2 About the dams 88
7.3 Dam safety assessment of five large irrigation dams 89
7.3.1 Background 89
7.3.2 Main features of the dams 89
7.3.3 Issues arising from site visits and dam safety reviews 90
7.3.4 Recommendations in the interest of safety 97
7.4 Conclusions and challenges 100
Notes 100
8 Case studies: Southeast Asia – Vietnam 101
8.1 About the country 101
8.2 About dams 102
8.3 Dam rehabilitation and safety improvement project 104
8.3.1 Project background 104
8.3.2 Dam classification, design and safety check floods 106
8.3.3 Reservoir sedimentation 108
8.3.4 Spillway capacity and safety against overtopping 108
8.3.5 Seepage through the embankment 110
8.3.6 Erosion of slopes due to dispersive soil properties 110
8.3.7 Upstream slope protection 110
8.3.8 Seismic stability of dams 111
8.3.9 Monitoring of dams 111
8.3.10 Capacity of local consultants 111
8.4 Conclusions and challenges 111
Notes 112